Volume 16, Issue 3 (Sep 2009) - Society of Ecological Chemistry

Transkrypt

SOCIETY OF ECOLOGICAL CHEMISTRY AND ENGINEERING
ECOLOGICAL CHEMISTRY
AND ENGINEERING S
CHEMIA I INŻYNIERIA EKOLOGICZNA S
Vol. 16
No. 3
Opole 2009
EDITORIAL COMMITTEE
Witold Wacławek (University, Opole) - Editor-in-Chief
Milan Kraitr (Western Bohemian University, Plzen, CZ)
Jerzy Skrzypski (University of Technology, Łódź)
Maria Wacławek (University, Opole)
Tadeusz Majcherczyk (University, Opole) - Secretary
PROGRAMMING BOARD
Witold Wacławek (University, Opole) - Chairman
Jerzy Bartnicki (Meteorological Institute - DNMI, Oslo-Blindern, NO)
Mykhaylo Bratychak (National University of Technology, Lviv, UA)
Bogusław Buszewski (Nicolaus Copernicus University, Toruń)
Andrzej Kulig (University of Technology, Warszawa)
Bernd Markert (International Graduate School [IHI], Zittau, DE)
Nelson Marmiroli (University, Parma, IT)
Jacek Namieśnik (University of Technology, Gdańsk)
Wanda Pasiuk-Bronikowska (Institute of Physical Chemistry PAS, Warszawa)
Lucjan Pawłowski (University of Technology, Lublin)
Krzysztof J. Rudziński (Institute of Physical Chemistry, PAS, Warszawa)
Manfred Sager (Agency for Health and Food Safety, Vienna, AT)
Mark R.D. Seaward (University of Bradford, Bradford, UK)
Jíři Ševčik (Charles University, Prague, CZ)
Piotr Tomasik (Agricultural University, Kraków)
Roman Zarzycki (University of Technology, Łódź)
Tadeusz Majcherczyk (University, Opole) - Secretary
EDITORIAL OFFICE
Opole University, Chair of Chemical Physics
POB 313, ul. Oleska 48, 45-951 OPOLE
tel./fax +48 77 455 91 49
email: [email protected]
http://tchie.uni.opole.pl
SECRETARIES
Agnieszka Dołhańczuk-Śródka, tel. +48 77 401 60 45, email: [email protected]
Małgorzata Rajfur, tel. +48 77 401 60 42, email: [email protected]
SECRETARIES' OFFICE
tel. +48 77 401 60 42
Copyright © by
Society of Ecological Chemistry and Engineering
Wydawnictwo dofinansowane przez
Ministerstwo Nauki i Szkolnictwa Wyższego w Warszawie
oraz Wojewódzki Fundusz Ochrony Środowiska i Gospodarki Wodnej w Opolu
ISSN 1898-6196
Dear Readers,
We would like to inform you, that our quarterly
Ecological Chemistry and Engineering S/Chemia i Inżynieria Ekologiczna S
starting from vol. 14(1) 2007
has been selected by the Thomson Scientific in Philadelphia for coverage in:
Science Citation Index Expanded
Journal Citation Reports/Science Edition
We thank very much
all Editorial Board members and Reviewers
for their efforts
and also Authors for presenting valuable papers
Editors
Szanowni Czytelnicy,
Miło jest nam poinformować, że kwartalnik
Ecological Chemistry and Engineering S/Chemia i Inżynieria Ekologiczna S
począwszy od vol. 14(1) 2007 został wybrany
przez the Thomson Scientific w Filadelfii do umieszczenia w następujących bazach:
Science Citation Index Expanded
Journal Citation Reports/Science Edition
Serdecznie dziękujemy Członkom Rady Programowej i Recenzentom
za dokładanie starań o wysoki poziom naukowy czasopisma,
a także Autorom za przedstawianie interesujących wyników badań
Redakcja
CONTENTS
Elena MASAROVIČOVÁ, Katarína KRÁĽOVÁ and Matúš PEŠKO
Energetic plants - cost and benefit .....................................................................
Marina V. FRONTASYEVA, Sergey S. PAVLOV, Liguri MOSULISHVILI
Elena KIRKESALI, Eteri GINTURI and Nana KUCHAVA
Accumulation of trace elements
by biological matrice of Spirulina platensis ......................................................
Waldemar WARDENCKI, Tomasz CHMIEL, Tomasz DYMERSKI
Paulina BIERNACKA and Beata PLUTOWSKA
Application of gas chromatography, mass spectrometry
and olfactometry for quality assessment of selected food products ...................
Magnuss VIRCAVS
Chemical composition and assessment of drinking water quality:
Latvia case study ...............................................................................................
Stephan FRANKE, Agnieszka SAGAJDAKOW, Lidia WOLSKA
and Jacek NAMIEŚNIK
Integrated approach - the effective tool for pollution level control
of sediments from Lake Turawskie ....................................................................
Małgorzata Anna JÓŹWIAK and Marek JÓŹWIAK
Influence of cement industry on accumulation of heavy metals
in bioindicators ..................................................................................................
Adam SMOLIŃSKI and Natalia HOWANIEC
Sustainable production of clean energy carrier - hydrogen ................................
Krzysztof BARBUSIŃSKI
Fenton reaction - controversy concerning the chemistry ...................................
Klaudiusz GRŰBEL, Alicja MACHNICKA and Jan SUSCHKA
Scum hydrodynamic disintegration
for waste water treatment efficiency upgrading .................................................
Grzegorz ŁAGÓD, Mariola CHOMCZYŃSKA, Agnieszka MONTUSIEWICZ
Jacek MALICKI and Andrzej BIEGANOWSKI
Proposal of measurement and visualization methods
for dominance structures in the saprobe communities .......................................
Ewa RADZIEMSKA, Piotr OSTROWSKI and Tomasz SERAMAK
Chemical treatment of crystalline silicon solar cells
as a main stage of PV modules recycling ...........................................................
Dorota KULIKOWSKA
Charactarization of organics and methods treatment of leachate
from stabilized municipal landfills ....................................................................
263
277
287
301
313
323
335
347
359
369
379
389
260
VARIA
15th International Conference on heavy metals in the environment ............................
Invitation for ECOpole’09 Conference ......................................................................
Zaproszenie na Konferencję ECOpole’09 ..................................................................
Guide for Authors on submission of manuscripts ......................................................
Zalecenia dotyczące przygotowania manuskryptów ...................................................
405
407
411
415
416
SPIS TREŚCI
Elena MASAROVIČOVÁ, Katarína KRÁĽOVÁ i Matúš PEŠKO
Rośliny energetyczne - koszty i korzyści ...........................................................
Marina V. FRONTASYEVA, Sergey S. PAVLOV, Liguri MOSULISHVILI
Elena KIRKESALI, Eteri GINTURI i Nana KUCHAVA
Akumulacja pierwiastków śladowych
w biologicznej matrycy z Spirulina platensis ....................................................
Waldemar WARDENCKI, Tomasz CHMIEL, Tomasz DYMERSKI
Paulina BIERNACKA i Beata PLUTOWSKA
Zastosowanie chromatografii gazowej, spektrometrii mas
i olfaktometrii w ocenie jakości wybranych produktów spożywczych ..............
Magnuss VIRCAVS
Skład chemiczny i ocena jakości wody pitnej.
Łotwa - studium przypadku ...............................................................................
Stephan FRANKE, Agnieszka SAGAJDAKOW, Lidia WOLSKA
i Jacek NAMIEŚNIK
Kompleksowa ocena stopnia zanieczyszczenia osadów dennych
Jeziora Turawskiego ..........................................................................................
Małgorzata Anna JÓŹWIAK i Marek JÓŹWIAK
Wpływ przemysłu cementowego na kumulację metali ciężkich
w organizmach bioindykatorów .........................................................................
Adam SMOLIŃSKI i Natalia HOWANIEC
Zrównoważona produkcja czystego nośnika energii - wodoru ..........................
Krzysztof BARBUSIŃSKI
Reakcja Fentona - kontrowersje dotyczące chemizmu ......................................
Klaudiusz GRŰBEL, Alicja MACHNICKA i Jan SUSCHKA
Intensyfikacja oczyszczania ścieków
z wykorzystaniem hydrodynamicznej dezintegracji piany .................................
Grzegorz ŁAGÓD, Mariola CHOMCZYŃSKA, Agnieszka MONTUSIEWICZ
Jacek MALICKI i Andrzej BIEGANOWSKI
Propozycja pomiaru podobieństwa struktury dominacji
zbiorowisk saprobów i wizualnej prezentacji zmian tej charakterystyki ...........
Ewa RADZIEMSKA, Piotr OSTROWSKI i Tomasz SERAMAK
Obróbka chemiczna krzemowych ogniw słonecznych
jako najważniejszy etap w recyklingu modułów fotowoltaicznych ...................
263
277
287
301
313
323
335
347
359
369
379
262
Dorota KULIKOWSKA
Charakterystyka oraz metody usuwania zanieczyszczeń organicznych
z odcieków pochodzących z ustabilizowanych składowisk
odpadów komunalnych ...................................................................................... 389
VARIA
15th International Conference on heavy metals in the environment ............................
Invitation for ECOpole’09 Conference ......................................................................
Zaproszenie na Konferencję ECOpole’09 ..................................................................
Guide for Authors on submission of manuscripts ......................................................
Zalecenia dotyczące przygotowania manuskryptów ...................................................
405
407
411
415
416
E C O LO GIC AL C H E M IS T R Y AN D E N GIN E E R IN G S
Vol. 16, No. 3
2009
Elena MASAROVIČOVÁ*1, Katarína KRÁĽOVÁ* and Matúš PEŠKO*
ENERGETIC PLANTS - COST AND BENEFIT
ROŚLINY ENERGETYCZNE - KOSZTY I KORZYŚCI
Abstract: Biomass energy has been recognized as one of the most promising and most important renewable
energy sources in the near future. In some countries of EU (like Slovakia and Poland), renewable energy
sources cover only around 6% of energy demand, whereby energy gained from biomass does not extend 3% in
the overall energy production. Hence European Commission has already supported all potential activities
related to alternative sources of energy, whereby biomass showed crucial position. It was emphasized that
besides of woody plant species as energetic plants can be also used both crops (mainly maize, rapeseed,
sunflower, soybean, sorghum, sugarcane) and non-food plants (eg switchgrass, jatropha, algae). In general,
energetic plant is a plant grown as a low cost and low maintenance harvest used to make biofuels, or directly
exploited for its energy content (heating or electric power production). Moreover, by-products (green waste) of
crops and non-food plants can be also used to produce biofuels. It was stressed that European production of
biodiesel from energy crops has grown steadily in the last decade, principally focused on rapeseed used for oil
as a substance in FAME (fatty acid methylester) production. Similar tendency was observed for bioethanol (as
a biocomponent in gasoline) prepared mainly from maize or cereals. Support of biofuel production reflected
response of many governments of EU countries to the long-term climatic changes and continuously increasing
price of crude oil as well as recently observed excess of cereals. At present bioethanol and FAME primarily
produced from the crops (maize and rapeseed) are used in the traffic. However, in the past these crops were
used only as a food. Consequently, a new ethical problem appeared: discrepancy between utilization of maize
and rapeseed as a food or as an alternative source of energy. It should be emphasize that large resources of
biomass energy are related also to forestry residues, forestry fuel wood and fast growing woody plants, mainly
willow, poplar, black locust and European alder. The first two mentioned species have already great tradition
for their plantation cultivation. In above-mentioned context, new biotechnological approach showed that
energetic plants have also significant application for environment friendly management, mainly in
phytoremediation technology. Phytoremediation was presented as a cleanup technology belonging to the costeffective and environment-friendly biotechnology. Thus several types of phytoremediation technologies being
used today were briefly outlined.
Keywords: alternative energy source, bioethics, biofuels, energetic plants, environment, phytoremediation
Introduction
In the worldwide scale biomass is the greatest source of renewable energy [1]. The
amount of energy stored in the biomass is approximately 7.5-times greater than is global
*
Faculty of Natural Sciences, Comenius University Bratislava, Mlynská dolina, SK-84215 Bratislava,
Slovakia
1
Corresponding Author: [email protected]
264
Elena Masarovičová, Katarína Kráľová and Matúš Peško
energy consumption. From the total technically exploitable energetic potential the
greatest share responded to biomass [eg 2]. Under condition of Slovakia it is actual to
use for energetic purposes forest biomass including energetic coppices, agricultural
biomass, wastes from wood-processing industry as well as food industry and waste
biomass from industrial and communal field. The use of forest biomass for energetic
purposes is relatively favourable. It is mainly residual wood and wood mass which could
not be used for other purposes (residua after timber production, smallwood of trees,
salvage timbre felling, etc.). For combustion are suitable wood pieces, wood chips,
briquettes or pellets made from forest biomass. It was shown that very perspective is
mainly cultivation of energetic forest coppices (willow, poplar, black locust tree). Woodworking industry represents approx. 40% portion from total technically utilizable
potential of biomass (wastes originated from mechanical processing of wood, filings,
bark). Biomass from the agriculture (straw, plant residues) arised either from cultivation
of crops (maize, cereals, rapeseed) or from food industry (pressing of oilseeds and fruits,
cutting of fruit trees or vine) (in details see [3]).
In the past few years, primary energy production from biomass in the EU has been
steadily increasing to 66.4 million Mg of crude oil equivalent in 2007. Wood-based
biomass is the main source for bioenergy in Europe, followed by waste and
agricultural-based biomass. Most of the biomass is used for heat, and to a lesser extent,
in combined heat and power (CHP) applications. In the EU the main producers are
countries with large territories and large forestry resources such as France, Sweden,
Germany, Finland and Poland. Biomass will play an increasingly important role in the
EU energy market with respect to the 20% target for renewable use by 2020 and in the
future reduction of CO2 emissions in Europe [1].
Biomass as a source of renewable energy
Compared with other countries energetic use of biomass in Slovakia nowadays
expressively falls behind to its potential energetic, economic and environmental
possibilities. The portion of assessing biomass on total consumption of primary
fuel-energetic sources is only 1%. However, considering all above-mentioned facts the
most perspective approach is the use of biofuels (biodiesel and gasoline with bioethanol)
on the basis of plant biocomponents (fatty acid methyl ester [FAME] from rapeseed or
sunflower oil in biodiesel; ETBE, (ethyl tert-butyl ether) or bioethanol in gasoline).
Biofuels are likely more ecological than conventional fossil fuels [4] what could be
a substantial argument mainly from the aspect of worldwide concentration increase of
greenhouse gases, mainly CO2 [5]. Further arguments supporting the use of biofuels are:
continually increasing price of liquid fossil fuels, the use of soils with lower quality class
for cultivation of technical crops, overproduction of crops with lower quality which
could not be used as a food. At present extraordinary attention is devoted to the study of
exploitation of both, second generation biofuels (produced from technical crops, which
could not be used as a food, as well as from biomass wastes) [6, 7] and third generation
biofuels (produced from transgenic - GM - energetic plants or from algae). However, the
most important biomass in Europe as a source of renewable energy is presented by
fast-growing trees like willow, poplar and to some extent alders (cf. [8, 9]).
Energetic plants - cost and benefit
265
Energetic plants
In general, energetic plants - EP (energy crops) are the plants grown as a low cost
and low maintenance harvest used to make biofuels, or directly exploited for its energy
content (heating or electric power production). If carbohydrate content is desired for the
production of biogas, whole-crops such as maize, Sudan grass, millet, white sweet clover
and many others, can be made into silage and then converted into biogas [6, 7]. Energy is
generated by burning plants grown for this purpose, often after the dry matter is
pelletized. EP are used for firing power plants, either alone or co-fired with other fuels.
Alternatively they may be used for heat or combined heat and power production. EP are
typically densely planted, high yielding species cultivated for the purpose of producing
(non-food) energy - burning wood or biofuel. According to Weger [10] for the choice of
suitable energetic plants following criteria could be considered: a) high biomass
production (mass, volume, energy content, b) manageability of cultivation (effective
cultivation techniques), c) biomass suitability for biofuel production (with respect to
different criteria for solid, liquid and gaseous fuels, respectively), d) economy of biomass
production (at a given economic conditions and financial subvention); e) environmental
aspects (eg greenhouse gases balance, invasive plant species, etc).
There are many species used as EP (eg [11]). Some of them are herbs (eg Zea mays,
Brassica napus, Triticum aestivum, Helianthus annuus, Helianthus tuberosus, Sorghum
bicolor, Miscanthus spp., Jatropha curcas), shrubs or trees (eg Populus spp., Salix spp.,
Alnus glutinosa, Ailanthus altissima, Ulmus montana). Since cultivation of the most of
above-mentioned herbs are in general very well known, therefore in the following text
our attention will be paid to cultivation of energetic trees - energy forestry. Basis for this
approach is sustainable tree biomass production presented eg by Andersson et al [12].
Energy forestry
Energy forestry is a form of forestry in which a fast-growing shrubs or trees are
grown specifically to provide biomass or biofuel for heating or power generation [cf. 12].
There they grow specifically to provide biomass or biofuel for heating or power
generation [cf. 13]. There are two forms of energy forestry: short rotation forestry
(SRF) and short rotation coppice (SRC) (in detail see [11, 14]). The first one are
species like alder, ash, birch and poplar grown for 8 to 20 years before the first harvest.
SRC uses high yield varieties of poplar and willow grown for 2 to 5 years before the first
harvest. This woody solid biomass can be used in applications such as district heating,
electric power generating stations, alone or in combination with other fuels [8, 9].
In forestry, plantations of trees are typically grown as an even-aged monoculture for
timber production, as opposed to a natural forest, where the trees are usually of diverse
species and diverse ages. A plantation is not a natural ecosystem. Plantations are also
sometimes known as "man-made forests" or "tree farms", though this latter term more
typically refers to specialist tree nurseries which produce the seedling trees used to create
plantations. More generally, a plantation is forest land where trees are grown for
commercial use, most often in a planted forest, but may also be in a naturally regenerated
forest. In the United States, the term “Tree Farm” is a trademark of the American Tree
Farm system, a third party verification system for certifying sustainable forestry. The
266
American Tree Farm system dates back to 1941 as a program to improve forestry
practices on farms. The term tree farm is also sometimes used to describe the sale of live
trees for landscaping. A plantation is usually made up of fast-growing trees planted either
to replace already logged forests or to substitute for their absence. Plantations differ from
natural forests in several ways: (a) plantations are usually monocultures - the same tree
species is planted in rows across a given area, whereas a conventional forest would
contain far more diverse tree species; (b) plantations may include introduced tree species
not native to the area, including unconventional types such as hybrid trees and
genetically modified (GM) trees. Since the primary interest in plantations is to produce
wood or pulp, the types of tree found in plantations are those that are best-suited to
industrial applications. For example, pine or spruce are widely used because of their fast
growth rate and are good for paper and timber production; (c) plantations are always
young forests. Typically, trees grown in plantations are harvested after 10 to 60 years,
rarely up to 120 years. This means that the forests produced by plantations do not contain
the type of growth, soil or wildlife typical of old-growth natural forest ecosystems. Most
conspicuous is the absence of decaying dead wood, a very important part of natural forest
ecosystems [cf. 8, 9].
SRF plantation for biomass as an alternative energy is stem production followed
either by replanting or by coppicing. Single stem systems utilise a range of hardwoods
and softwoods, whereas a coppice system utilises hardwood genera, primarily Salix and
Populus. In order to maximise the stored chemical energy in the biomass (in terms of
GJ/ha/yr), a SRF coppice grower should ideally plant tree species with vigorous growth
and coppicing ability best suited to the local conditions. When grown at relatively high
densities as compared with traditional plantation forests, this would result in high mean
annual increments of biomass. Although many parameters are important determinants of
the suitability of a tree species grown for SRF, total biomass yield (in terms of
megagrams of aboveground dry matter per hectare per year, Mg d.m./ha/yr), is
considered to be the most important as it indicates the ability to produce actual
marketable fuelwood product. Biomass yields vary with species, age of root stock,
population density, length of rotation and time of harvest [eg 8, 11]. Typically the yield
of a first coppice Eucalyptus harvest can be double that of the single stem harvest, with
the second coppice harvest yielding around 150%, and the third coppice harvest yielding
100%, ie similar to that of the establishment crop harvest. Similarly, reported yields of
Salix viminalis were 5.7 Mg d.m./ha/yr after 2-yr growth in the establishment rotation
compared with 8.3 Mg d.m./ha/yr following the first 2-yr coppice rotation.
Energetic plants and climatic changes
Anthropogenic factors continue to elevate atmospheric CO2 concentration, which on
average has already exceeded 377 ppm in the year 2006 [15] which shows a substantial
increase from 280 ppm in the year 1750 (IPCC 2001). The change in atmospheric CO2 is
correlated to the 0.8°C increase in global average surface temperature in the past century,
and the warming rate of about 0.2°C per decade [16]. Biomass can be used to produce
C-neutral fuels to power for transportation industry [17]. Biomass fuels are C-neutral
because they release recently-fixed CO2, which does not shift the C-cycle. Biomass may
267
generate the same amount of CO2 as fossil fuels per unit C, but every time a new plant
grows it removes that same CO2 from the atmosphere [11].
Support of biofuels reflected response of energetic plants production to the
long-term climatic changes in connection with quantitative and qualitative parameters of
bio-components in biofuel. In agricultural practice it was recognized that the screening of
new varieties of rapeseed (for biodiesel) or maize (for bioethanol) should be done in the
relationship to the actual or long-term climatic changes with respect to resistance against
the drought and temperature stress. This fact is a challenge for agronomists, plant
physiologists and production ecologists to solve the above-mentioned topic. Selection of
growth parameters and climatic factors which are the most important for formation of
plant biomass and seed production (eg maize and rapeseed) will be needed.
Causes of both short-term and long-term climatic changes on the earth are discussed
for many years (eg Kyoto Protocol 1997, summit OSN, Bali 2007). Nowadays
9 milliards Mg of carbon are emitted from anthropogenic sources into atmosphere [18].
We suppose that high greenhouse gases concentration in atmosphere will increase
temperature of our planet, mainly in the north hemisphere.
Besides the most important greenhouse gas, CO2 the further greenhouse gas - N2O
outcoming from fertilization (especially rapeseed) is intensively discussed [19]. This gas
was classified as a third most important greenhouse at all. Its global warming potential
(GWP) is 296x higher than GWP of CO2 [5]. It could be supposed that N2O emission
will increase in connection with higher cultivation area of rapeseed.
In the last century in Slovakia increase of mean year air temperature approx. about
1.1°C and decrease of year sum of atmospheric rainfall about 5.6% were observed.
Intensive decrease of both relative air humidity (to 5%) and snow cover in the whole area
of Slovakia were observed. These observations confirmed that mainly southern part of
Slovakia is gradually dried - potential evapotranspiration increased and soil humidity
decreased; changes in global irradiance were not found [18].
In actual agriculture it should be focused to maintenance management, which is
system with natural soil recovery and without environment destructions. This approach
will need a new climatic regionalization and new structure of crops to use effectively all
natural sources - mainly irradiance balance and water regime. Geneticists should focus
to find new genotypes and hybrids with higher resistance to abiotic and biotic stresses.
The EU Energy and Climate Change Package (CCP) was finally adopted by the
Council on April 6, 2009. The Renewable Energy Directive (RED), which is part of this
package, was completed in December 2008 and was entered in force on June 25, 2009.
This package includes the „20/20/20” goals for 2020 [1]:
20% reduction in greenhouse gas (GHG) emissions compared with the levels of the
year 1990
20% improvement in energy efficiency compared with current forecasts for the year
2020
20% share for renewable energy in the EU energy mix (consumption). Part of this
20% share is a 10% minimum target for renewable energy consumed in transport to
be achieved by all Member States (most, but not all of this 10% will come from
increased biofuel use).
268
Invasive and genetically modified energetic plants - potential risk for
the environment?
Several biofuel crops, which many countries are promoting as an alternative to fossil
fuels, have many traits in common with invasive species [20, 21]. These species fulfil
characteristics of an ideal biomass crop: low energy into maintenance relative to the
production of energy-rich biomass; efficient use of irradiance, water and nutrients;
C4 photosynthesis; nutrient translocation into storage organs during the non-growing
season; and perennial growth. Domestication of non-native crops, in fact, is considered
one of the main pathways of biological invasions [22]. In particular, according to Barney
and DiTomaso [21], biofuel feedstock can survive in conditions that mimic natural
habitat.
The enhancement of environmental tolerance in GM energetic plants likely will
increase the risk of invasion into surrounding environments. Similarly, enhancement of
aboveground biomass production via biotechnology could allow such cultivars to be
more competitive with native vegetation or other cultivated crops. Genetic modification
can change the phenotype or physiology of a plant species sufficiently to lead to
alterations in plant-plant interactions and ecological functions. Thus, it is important to
recognize that, like non-native species, even native plants - if modified - would pose an
unknown risk of becoming invasive [23].
On the other hand, as exemplified by the sterile biofuel crop miscanthus
(Miscanthus × giganteus), a lack of seed production can decrease the risk of escaping
cultivation dramatically [24]. Sterile cultivars can decrease the likelihood of biofuel
species escaping from production fields. However, it should be stressed that
Miscanthus × giganteus is an allopolyploid that does not produce viable seed and
reproduces vegetatively. Therefore allopolyploidy does not guarantee continued sterility
and vegetative propagation is often associated with invasiveness or directly contributes to
it [20].
Based on above-mentioned facts it should be beneficial to perform genotype-specific
pre-introduction screening for a target region, which consists of risk analysis,
climate-matching modelling, and ecological studies of fitness responses to various
environmental scenarios. Such screening procedure will provide reasonable assurance
that economically beneficial biofuel crops will pose a minimal risk of damaging native
and managed environment [21].
Biofuels - environment friendly approach
Practical application of biofuels in the last decade arised from crude oil crisis as well
as from global rise of temperature connected with higher production of greenhouse gases,
mainly CO2. Thus promotion of the production and use of biofuels could contribute to
a reduction in energy import dependency and in emissions of greenhouse gases.
Moreover, biofuels, in pure form or as a blend, may in principle be used in existing
motor vehicles and utilized by current motor vehicle fuel distribution system. The
blending of biofuel with fossil fuels could facilitate a potential cost reduction in the
distribution system in the EU. Some countries are already using biofuel blends of 10%
and higher. The Commission Green Paper „Towards a European strategy for the security
269
of energy supply” sets the objective of 20% substitution of conventional fuels by
alternative fuels in the road transport sector by the year 2020 (in detail see [25]).
Biofuel is renewable fuel that can be prepared from vegetable oils, animal fats, or
recycled restaurant greases. Biodiesel is safe, biodegradable, and reduces serious air
pollutants such as particulates, carbon monoxide, hydrocarbons, and air toxics. In spite of
these facts progress in biofuel use is nowadays still discussed.
First-generation biofuels rely on food plant species (crops) as their feedstock.
Corn, soy, rapeseed and sugarcane all have readily accessible sugars, starches and oils.
Thus to change them into biofuels simply involves either fermenting the sugars or
transform the fatty oils through transesterification. Second-generation biofuels use
lignocellulosic biomass as feedstock (mainly wood, ie trees), non-food plants like
switchgrass (Panicum virgatum) and agricultural residue (as well as other organic
wastes) such as corn stalks. Using specially designed microorganisms, the feedstock’s
tough cellulose is broken down into sugar and then fermented. Alternatively,
a thermochemical route can be taken whereby the biomass is gasified and then liquefied,
a process known as „biomass-to-liquid” (BtL). Rather than improving the fuel-making
process, third-generation biofuels seek to improve the feedstock. Designing oilier
crops, for example, could greatly boost yield. Scientists (geneticists) have designed
poplar trees (ie GM poplars) with content to make them easier to process. Researchers
have already mapped the genomes of sorghum and corn, which may allow genetic
agronomists to change the genes controlling oil production. Thus, third generation
biofuels are carbon neutral when consumed meaning that the crops consume the same
amount of carbon from the atmosphere as they will release when combusted. This is done
through GM and nowadays it is not yet commercially available. Fourth-generation
technology combines genetically optimized feedstocks, which are designed to capture
large amounts of carbon, with genomically synthesized microbes, which are made to
efficiently make fuels. Key to the process is the capture and sequestration of CO2,
a process that renders fourth-generation biofuels a „carbon negative” source of fuel.
However, the weak link is carbon capture and sequestration technology, which continues
to elude the coal industry (in detail see [26]). For carbon negative crop the amount of
carbon consumed during the crops growth is bigger than the amount released when
combusted in an engine. This is made possible through genetic engineering of the crops.
Taking into account all of the issues lately with global warming fourth generation
biofuels become a very attractive option as a renewable energy source. A carbon negative
fuel will reduce carbon levels in the atmosphere allowing us to combat global warming as
we also shift to a renewable fuel [27].
Considering the above-mentioned facts from the aspect of biomass utilization for
biofuel production significant possibilities for applied physiological and production
research of some crops, eg rapeseed [28-30], sunflower [31], soya, amaranthus (FAME,
addition to biodiesel), maize, potatoes, barley (ETBE and bioethanol addition to
gasoline) are shaped. From cultivation and climatic aspect the most perspective for
Slovakia are rapeseed (FAME) and maize (ETBE and bioethanol), technological
processing of which is realized by companies Enviral and Meroco in factories for FAME
and bioethanol production. Annual output of 120 millions dm3 of bioethanol and
100 000 Mg of FAME are challenge for achievement of the goal - up to 2010 to enhance
the portion of biofuels in conventional fuels from actual 4.75% to 5.75%. It will be
270
necessary to secure the presented biethanol production predominantly from
self-production. However, the increased demand for maize and rapeseed could not be
secured by raising of cultivation area but by increasing yield per hectare. Slovakia with
mean yield per hectare corresponding to 6 Mg of maize falls behind countries without
tradition in maize cultivation, such are Czech Republic or Poland. For comparison: in
neighbouring Austria achieve yearly on average 10 Mg maize per hectare. Similar
situation is also in the case of FAME. At present 65% of FAME demand realizes
Slovnaft from the import. After recent start of the plant in Leopoldov in the future the
majority of FAME could originate from inland production [25].
With respect to the fact, that assortment of actually utilized rapeseed and maize
cultivars (which is available at Central and Testing Institute in Agriculture in Bratislava,
Slovakia) was obtained on the basis of biomass of vegetation organs as well as on the
quantity and quality of fruits (seed of rapeseed, maize grain) it is necessary to complete
the missing physiological parameters which will serve as a base for economic yield of
crops. Based on these data it will be possible to select and advise such cultivars of
rapeseed and maize which will be suitable for cultivation also from the aspect of on the
long-term changing climatic conditions of Slovakia.
In the agricultural experience it was shown that in respect to climatic changes in
Slovakia (perspective of a climate characterized with higher temperature and drought,
[18]) it would be necessary to perform screening of new cultivars and lines of crops,
which will be more resistant against stress induced by drought and temperature as well as
against black frost in the regions where the snow cover will be not sufficient. This fact
present a challenge for agronomists, plant physiologists and production ecologists to
contribute to solving of this problem - to select those parameters which are the most
important for the production of plant biomass and from the climatic factors to determine
those which are the most important from the aspect of the influence of plant biomass
production. It would be necessary to take such actions which will secure that the use of
crops for technical purposes will not limit their utilization as agricultural crops.
The major benefit of biofuels is the potential to reduce net CO2 emissions to the
atmosphere. Enhanced C management may make it possible to take CO2 released from
the fossil C cycle and transfer it to the biological C cycle to enhance food, fiber, and
biofuel production as well as sequester C for enhancing environmental quality [11].
According to EU Energy and Climate Change Package biofuels have to meet certain
criteria to be considered for the 10% goal: They must meet the sustainability criteria, eg
they must reduced GHG emissions by at least 35% compared with fossil fuels beginning
autumn 2010. From the year 2017 the reduction has to be 50%, and at least 60% for new
installations. Biofuels made out of ligno-cellulosic, non-food cellulosic, waste and
residue materials will count double towards the goal (calculation made on energy basis),
renewable electricity consumed by cars will be counted by factor 2.5. However, accoring
to European Comission, biofuels may not be made from raw material obtained from land
with high biodiversity value such as primary forest and other wooded land areas
designated by law or by relevant competent authority for nature protection purposes,
highly biodiverse grassland or highly biodiverse non-grassland. Biofuels shall not be
made from raw materials produced on the land with high carbon stock such as wetlands,
peatlands or continuously forested areas [1].
271
Phytoremediation - cost-effective green biotechnology
Environmental pollution with xenobiotics including toxic metals is still serious
global problem. Development of phytoremediation technologies for the plant-based
clean-up of contaminated substrates is therefore of significant interest. Phytoremediation
is environment-friendly and cost-effective green technology for the removing of toxic
metals and organic pollutants from the environment using some species of the plants.
There are several types of phytoremediation technologies currently available for clean-up
of both contaminated soils and water. The most important of them are these: reduction of
soil metal concentration by cultivating plants with a high capacity for metal accumulation
in the shoots (phytoextraction), adsorption or precipitation of metals onto roots or
absorption by the roots of metal-tolerant aquatic plants (rhizofiltration), immobilization
of metals in soils by root uptake, adsorption onto roots or precipitation in the rhizosphere
(phytostabilization), decomposition of organic pollutants by rhizosphere
microorganisms (rhizodegradation), absorption of large amounts of water by fast
growing plants and thus prevent expansion of contaminats into adjacent uncontaminated
areas (hydraulic control) and re-vegetation of barren area by fast grown plants that
cover soils and thus prevent the spreading of pollutants into environment
(phytorestauration) [eg 32, 33].
The most effective but also technically the most difficult phytoremediation
technology is phytoextraction involving the cultivation of metal-tolerant plants that
concentrate soil contaminants in their aboveground tissues. At the end of the growth
period, plant biomass is harvested, dried or incinerated, and the contaminant-enriched
material is deposited in a special dump or added into a smelter. The energy gained from
burning of the biomass could support the profitability of this technology, if the resultant
fumes can be cleaned appropriately. For phytoextraction to be effective, the dry biomass
or the ash derived from aboveground tissues of a phytoremediator crop should contain
substantially higher concentrations of the contaminant than the polluted soil [34].
Metal-tolerant species (including some of energetic plants, eg Hordeum vulgare,
Triticum aestivum, Brassica napus, Brassica juncea, Helianthus annuus, Salix spp.,
Populus spp.) can accumulate high concentration of some toxic metals in their
aboveground biomass. One subset of larger category of metallophytes are
hyperaccumulators (metal extractors). However, besides hyperaccumulators the
fast-growing (high-biomass-producing) plants can also be used in phytoremediation
technology. In spite of lower shoot metal-bioaccumulating capacity of these species, the
efficient clean-up of contaminated substrates is connected with their high biomass
production. Perttu and Kowalik [35] have already recognized that it is both
environmentally and economically appropriate to use vegetation filters of short rotation
willow to purify waters and soils. Similarly, Aronsson et al [36] successfully used
short-rotation willow coppice for remediation of wastewater.
The time it takes for plants to reduce the amount of heavy metals in contaminated
soils depends on two factors: how much biomass these plants produce and their metal
bioconcentration factor, which is the ratio of metal concentration in the shoot tissue to
the soil [37]. The latter factor is determined by the ability and capacity of the roots to
take up metals and load them into the xylem, by the mass flow in the xylem to the shoot
in the transpiration stream, and by the ability to accumulate, store and detoxify metals
272
while maintaining metabolism, growth and biomass production [38-40]. With the
exception of hyperaccumulators, most plants have metal bioconcentration factors less
than 1, which means that it takes longer than a human lifespan to reduce soil
contamination by 50%. To achieve a significant reduction of contaminants within one or
two decades, it is therefore necessary to use plants that excel in either of these two
factors, eg to cultivate crops with a metal bioconcentration factor of 20 and a biomass
production of 10 tonnes per hectare (Mg/ha), or with a metal bioconcentration factor of
10 and a biomass production of 20 Mg/ha [41].
As mentioned above, two possible strategies have emerged to improve the
phytoextraction of heavy metals: growing plant phenotypes that are able to accumulate
large concentrations of heavy metals in their aboveground parts, or using phenotypes that
are able to produce high biomass with average heavy-metal concentration in their
harvestable tissue. Of course, it would be desirable to combine both features and design
plants that are specialized for fast growth and hyperaccumulation. This is the
fundamental aim that underlies efforts to generate transgenic plants for phytoremediation.
Pilon-Smits and Pilon [42] focused on the design and creation of transgenic plants for
phytoremediation of metals. Other than plant growth, which depends on numerous
genetic and non-genetic factors, the accumulation of heavy metals is controlled by only
a few gene loci and is therefore more easily accessible for genetic manipulation [43].
It should be stressed that from above-mentioned phytoremediation technologies the
most frequent practical application has phytoextraction which has been growing rapidly
in popularity worldwide for the last twenty years. In general, this process has been tried
more often for extraction of toxic metals than for organic substances. A living plant may
continue to absorb contaminants until it is harvested. After harvest a lower level of the
contaminant will remain in the soil, so the growth/harvest cycle must usually be repeated
through several crops to achieve a significant cleanup. After the process, the cleaned soil
can support other vegetation.
Phytoextraction as an environment friendly method could be used for cleaning up
sites that are contaminated with toxic metals. However, the method has been questioned
because it produces a biomass-rich secondary waste containing the extracted metals.
Therefore, further treatment of this biomass is necessary. Gasification (ie pyrolysis),
which occurs under reducing conditions, was a better method than incineration under
oxidizing conditions to increase volatilization and, hence subsequently recovery, of Cd
and Zn from plants. It would also allow the recycling of the bottom ash as fertilizer [44].
Recovery of energy by biomass burning or pyrolysis could help make phytoextraction
more cost-effective. Processing of biomass to produce energy and valuable ash in a form
which can be used as ore or disposed safely at low cost. Recovery of energy by biomass
burn or pyrolysis could help make phytoextraction cost effective [45].
Within the Brassica genus, there also exist some other species which show the
tendency to accumulate high metal concentrations, and which can be characterized as
metal accumulators. Some of these species grow fast and produce a high biomass.
Examples are Brassica juncea (Indian mustard), Brassica rapa (field mustard) or
Brassica napus (rapeseed) [46]. If soils, contaminated with heavy metals, are
phytoremediated with oil crops (such as Brassica spp.), biodiesel production from the
resulting plant oil could be a viable alternative to generate bioenergy. If biodiesel exhaust
fumes from such rapeseed plants - specifically selected for their high toxic metal uptake
273
capacity - will have hazardous metal emissions is virtually unknown. Further scientific
research to investigate this issue is essential. It is crucial that the remediation effect of the
plant will not be negated by higher toxic metal emissions of vehicles, running on
biodiesel obtained from phytoremediation plants [47].
Energetic plants vs bioethics aspects
In connection with the increasing trend of biofuel use an important ethical problem
occurred - perplexity whether crops (eg maize, cereals, potatoes, rapeseed, and
sunflower) could be used exclusively for alimentary purposes or also as an alternative
energy source. Astyk [48] published twelve ethical principles which describe all actual
aspects (both positive and negative) of biofuels. It can be observed that the former
enthusiasm was replaced by scepticism. After initial opinion that biofuels can save the
mankind advice appeared that biofuels are curse of this civilization. In the laic
community even such mind arised that biofuels represent a „silent tsunami” which leave
behind hungry and poor people. Moreover, serious factor also is the increase of the soil
portion designated for cultivation of technical crops at the expense of forests and natural
vegetation, what could be reflected in the biodiversity decline. These assumptions
evoked negative reflection in the world, too. Therefore, acceptance of fundamental
principles of bioethics is needed.
Conclusion
Worldwide increase of biofuel production responded not only to marked global
climatic changes but also to continually increasing price of crude oil and excess of
cereals in recent past. In March 2007, the leaders of EU obliged that up to year 2020 the
portion of alternative energy sources will be enhanced to 20%, there of the portion of
biofuels at least to 10%. Nowadays in EU countries the most important three types of
biofuels occurred - gasoline with the addition of ETBE or bioethanol, biodiesel and pure
plant oil (PPO). These biofuels are produced from agricultural crops which were in the
past utilized only for food industry (first generation of biofuels). In connection with the
increasing tendency of biofuel use an important ethical problem occurred - perplexity
whether crops (eg maize, cereals, potatoes, rapeseed and sunflower) could be used
exclusively for alimentary purposes or also as an alternative energy source. Serious fact
is also the increase of the soil portion designated for cultivation of technical crops on the
expense of forests and original natural vegetation, what is reflected in biodiversity
decline. These findings evoked negative reflection in the world. However, it should be
recognised that in the case of rapeseed, the oil can be used not only for FAME
production, but rapeseed cakes as a residue after seed pressing represent a high-grade
fodder for animal husbandry and the waste-straw represents staple for second generation
biofuels, because by hydrolysis of polysaccharides and subsequent fermentation superior
bioethanol can be prepared. Similarly, glycerol generated at FAME production (10%
portion) can be utilized either as a liquid fuel, in chemical and cosmetic industry or as
fodder for cattle. Designing of trees, that store significantly more carbon dioxide than is
their CO2 emission, are very perspective for production of the 'fourth generation' of
biofuels. Nevertheless, with the above-mentioned biological and ethical aspects further
274
spheres (sociological and political) of the global society are connected which is
important for incoming development of the human population, too.
Acknowledgements
This study was in part financially supported by Company for production and use of
biofuels, AZC, a.s., Bratislava, Slovak Republic.
References
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
Flach B. et al: Netherlands-Germany EU-27/ EU-27 Biofuels Annual. Annual Report 2009. Gain Report
Number: NL9014, Date 6/15/2009
http://gain.fas.usda.gov/Recent%20GAIN%20Publications/General%20Report_The%20Hague_
Netherlands-Germany%20EU-27_6-15-2009.pdf
Jasiulewicz M. and Jasiulewicz R.: Biomass from energetic plants as a renewable energy source. Stow.
Ekonom. Roln. Agrobiol. 2009, 7, 48-51.
Kisely P. and Horbaj P.: Possibility for the biomass utilisation in Rožňava region. Contribution
presented at the Workshop “Preparation of biomass as a fuel for small heating systems for biomass local solutions for local Requirement”. Kysucký Lieskovec, June 19-20, 2006.
http://www.biomasa.sk/files/jrccleanweb.pdf
Kráľová K. and Masarovičová E.: Minimalisation of the risks for environment at rapeseed cultivation
for use as biofuels. (in Slovak). [In:] A. Manová, F. Čacho (ed.): Proc. 28th Conference of Industrial
Toxicology 08. Tatranská Štrba, June 18-20, 2008, p. 311-315.
Crutzen P.J., Mosier A.R., Smith K.A. and Winiwarter W.L.: N2O release from agro-biofuel production
negates global warming reduction by replacing fossil fuels. Atmos. Chem. Phys. Discuss., 2007, 7,
11191-11205.
Carere C.R., Sparling R., Cicek N. and Levin D.B.: Third generation biofuels via direct cellulose
fermentation. Int. J. Mol. Sci., 2008, 9, 1342-1360.
Hertwich E.G. and Zhang X.: Concentrating-solar biomass gasification process for 3rd generation
biofuels. Environ. Sci. Technol., 2009, 43, 4207-4212.
Perttu K.L.: Environmental justification for short-rotation forestry in Sweden. Biomass Bioenergy,
1998, 15, 1-6.
Perttu K.L.: Environmental and hygienic aspects of willow coppice in Sweden. Biomass Bioenergy,
1999, 16, 291-297.
Weger J.: Energy crops in Czech Republic and in EU (In Czech). 2007.
http://www.vukoz.cz/vuoz/biomass.nsf/pages/eplodiny.html
Johnson J.M.F., Coleman M.D., Gesch R., Jaradat A., Mitchell R., Reicosky D. and Wilhelm W.W.:
Biomass- Bioenergy Crops in the United States: A Changing Paradigm. Am. J. Plant Sci. & Biotech.,
2007, 1, 1-28. http://www.globalsciencebooks.info/JournalsSup/images/SF/AmJPSB_1(1)1-28.pdf
Andersson F.O., Ågren G. and Führer E.: Sustainable tree biomass production. Forest Ecol. Manage.
2000, 132, 51-62.
Perttu K.L. and Kowalik P.J.: Modelling of energy forestry: growth, water relations and economics.
PUDOC, Wageningen 1989, 198 pp.
Sims R.E.H., Maiava T.G. and Bullock B.T.: Short rotation coppice tree species selection for woody
biomass production in New Zealand. Biomass Bioenergy, 2001, 20, 329-335.
Blasing T.J. and Smith K.: Recent Greenhouse Gas Concentrations. Oak Ridge National Laboratory,
United State Department of Energy. Available, 2006. http://cdiac.ornl.gov/pns/ current_ghg.html
Hansen J., Sato M., Ruedy R., Lo K., Lea D.W. and Medina-Elizade M.: Global temperature change.
Proc. Natl. Acad. Sci. USA, 2006, 103, 14288-14293.
Hoffert M.I., Caldeira K., Benford G., Criswell D.R., Green C., Herzog H, Jain A.K., Kheshgi H.S.,
Lackner K.S., Lewis J.S., Lightfoot H.D., Manheimer W., Mankins J.C., Mauel M.E., Perkins L.J.,
Schlesinger M.E., Volk T. and Wigley T.M.L.: Advanced technology paths to global climate stability:
energy for a greenhouse planet. Science, 2002, 298, 981-987.
Balajka J., Lapin M., Minďáš J., Šťastný P. and Thalmeinerová D.: Fourth National Report of SR about
State of Climate and Report about Attained Progress at Fulfilling Kyoto Protocol [in Slovak]. Ministry of
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
[28]
[29]
[30]
[31]
[32]
[33]
[34]
[35]
[36]
[37]
[38]
[39]
[40]
[41]
275
Environment of Slovak Republic and Slovak Institute of Hydrometeorology. Bratislava, Slovak
Republic. 2005.
Mosier A.R., Duxbury J.M., Freney J.R., Heinemeyer O. and Minami K: Nitrous oxide emissions from
agricultural fields: Assessment, measurement and mitigation. Plant Soil, 1996, 181, 95-108.
Raghu S., Anderson R.C., Daehler C.C., Davis A.S., Wiedenmann R.N., Simberlof D. and Mack R.N.:
Adding Biofuels to the Invasive Species Fire? Science, 2006, 313, 1742.
Barney J.N. and DiTomaso J.M.: Non-native Species and Bioenergy: Are We Cultivating the Next
Invader? BioScience, 2008, 58, 64-70.
Reichard S.H. and White P.: Horticulture as a pathway of invasive plant introductions in the United
States. BioScience, 2001, 51, 103-113.
DiTomaso J.M., Barney J.N. and Fox A.M.: Biofuel Feedstocks: The Risk of Future Invasions. CAST
Commentary QTA 2007-1, CAST, Ames, Iowa 2007.
Lewandowski I., Clifton-Brown J.C., Scurlock J.M.O. and Huisman W.: Miscanthus: European
experience with a novel energy crop. Biomass Bioenergy, 2000, 19, 209-227.
Masarovičová E., Kráľová K., Brestič M. and Olšovská K.: Production potential of rapeseed in
environmental conditions of Slovakia from aspect of use in „FAME“ production [in Slovak]. In:
D. Bratský (ed.); Proc. 8th International Conference Motor Fuels 2008. Tatranské Matliare, June 23-26,
2008, VTS Slovnaft, Bratislava, p. 520-536.
Rubens C.: WTF Are Fourth-Generation Biofuels? 2008. http://earth2tech.com/2008/03/04/wtf-arefourth-generation-biofuels/
Leigh M.L.: Fourth Generation Biofuels. 2009. http://ezinearticles.com/?Fourth-GenerationBiofuels&id=2139086
Remišová V. and Vinceová A.: Effect of air temperature on flowering onset of rapeseed in Slovakia (in
Slovak). [In:] J. Rožňovský, T. Litschmann, I. Vyskot (eds.): Phenology response of climate variability.
March 3, 2006, Brno, Czech Republic, p.1-5
Šrojtová G.: Course of climatic conditions and their effect on rapessed yield (in Slovak). [In:]
Proceedings of Research Papers of Research Institute of Crop Production in Piešťany - Institute of
Agroecology in Michalovce, Slovakia, 2005, p.15-22.
Šrojtová G.: Evaluation of relationship between climatic conditions rapeseed yield. (in Slovak). [In:]
Bioclimatology and water in the land: International Bioclimatological Conference. Bratislava: Library
and Publishing Center of the Faculty of Mathematics and Physics. Comenius University, Bratislava
2007, p. 209.
Jambor M., Zubal P. and Karaba S.: Rationalization of components of rapeseed and sunflower
cultivation technologies. Realization Methods. Research Institute of Crop Production, Piešťany, Slovak
Republic, p. 22. Kysucký Lieskovec, June 19-20, 2006.
Meagher R.B.: Phytoremediation of toxic metal and organic pollutants. Curr. Opion. Plant Biol., 2000,
3, 153-162.
Masarovičová, E. and Kráľová K.: Medicinal plants - past, nowadays, future. Acta Hort., 2007, 749,
19-27.
Krämer U.: Phytoremediation: novel approaches to cleaning up polluted soils. Curr. Opin. Biotech.,
2005, 16, 133-141.
Perttu K.L. and Kowalik P.J.: Salix vegetation filters for purification of waters and soils. Biomass
Bioenergy, 1997, 12, 9-19.
Aronsson P., Heinsoo K., Perttu K. and Hasselgren K.: Spatial variation in above-ground growth in
unevenly wastewater-irrigated willow Salix viminalis plantations. Ecol. Eng., 2002, 19, 281-287.
McGrath S.P. and Zhao F.J.: Phytoextraction of metals and metalloids from contaminated soils. Curr.
Opin. Biotech., 2003, 14, 277-282.
Gleba D., Borisjuk N.V., Borisjuk L.G., Kneer R., Poulev A., Skarzhinskaya M., Dushenkov S.,
Logendra S., Gleba Y.Y. and Raskin I.: Use of plant roots for phytoremediation and molecular farming.
Proc. Natl. Acad. Sci. USA, 1999, 96, 5973-5977.
Guerinot M.L. and Salt D.E.: Fortified foods and phytoremediation. Two sides of the same coin. Plant
Physiol., 2001, 125, 164-167.
Clemens S., Palmgren M.G. and Krämer U.: A long way ahead: understanding and engineering plant
metal accumulation. Trends Plant Sci., 2002, 7, 309-315.
Peuke A.D. and Rennenberg H.: Phytoremediation. EMBO Rep. 2005, 6, 497-501.
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1369103
276
[42] Pilon-Smits E. and Pilon M.: Phytoremediation of metals using transgenic plants. Crit. Rev. Plant Sci.
2002, 21, 439-456.
[43] Clemens S.: Molecular mechanisms of plant metal tolerance and homeostasis. Planta, 2001, 212,
475-486.
[44] Keller C., Ludwig C., Davoli F. and Wochele J.: Thermal treatment of metal-enriched biomass produced
from heavy metal phytoextraction. Environ. Sci. Technol., 2005, 39, 3359-3367.
[45] Li Y.M., Chaney R., Brewer E., Roseberg R., Angle J.S., Bake A., Reeves R. and Nelkin J.:
Development of a technology for commercial phytoextraction of nickel: economic and technical
considerations. Plant Soil, 2003, 249, 107-1105.
[46] Ebbs S.D. and Kochian L.V.: Toxicity of Zn and Cu to Brassica species: implications for
phytoremediation. J. Environ. Qual., 1997, 26, 776-781.
[47] Van Ginneken L., Meers E., Guisson R., Ruttens A., Elst K., Tack F.M.G., Vangronsveld J., Diels L. and
Dejonghe W.: Phytoremediation for heavy metal-contaminated soils combined with bioenergy
production. J. Environ. Eng. Land. Manage., 2007, 15, 227-236.
[48] Astyk S.: Ethics of biofuels. Energy Bull., 28.12.2006. http://www.energybulletin.net/node/24169
ROŚLINY ENERGETYCZNE - KOSZTY I KORZYŚCI
Abstrakt: Energia biomasy jest uznana za jedno z najbardziej obiecujących i najważniejszych odnawialnych
źródeł energii. W niektórych krajach Unii Europejskiej (np. Słowacja i Polska) odnawialne źródła energii
pokrywają tylko około 6% zapotrzebowania na energię, przy czym uzyskana energia z biomasy nie przekracza
3% w ogólnej produkcji energii. Dlatego Komisja Europejska popiera wszystkie potencjalne działania
związane z alternatywnymi źródłami energii, w których biomasa zajmuje kluczową pozycję. Podkreślono, że
oprócz gatunków roślin drzewiastych, jako rośliny energetyczne mogą być również wykorzystywane uprawy
(głównie kukurydzy, rzepaku, słonecznika, soi, sorgo, trzciny cukrowej) i inne rośliny niespożywcze
(np. proso, jatrofa, glony). Ogólnie rzecz biorąc, uprawa roślin energetycznych, wykorzystywanych do
produkcji biopaliw lub bezpośredniego uzyskania energii (ogrzewanie lub produkcja energii elektrycznej),
wymaga małych nakładów finansowych na jej utrzymanie i zbiór roślin. Ponadto, produkty uboczne upraw
(odpady zielone) i inne rośliny niespożywcze mogą być także wykorzystywane do produkcji biopaliw.
Podkreślono, że europejska produkcja biodiesla z roślin energetycznych stale rośnie w ostatnim
dziesięcioleciu, koncentrując się głównie na oleju rzepakowym stosowanym jako substancja w produkcji
FAME (estry metylowe kwasów tłuszczowych). Podobne tendencje zaobserwowano w przypadku bioetanolu
(jako biokomponentu benzyny), otrzymywanego głównie z kukurydzy i zbóż. Wsparcie produkcji biopaliw
jest reakcją wielu rządów krajów UE na długoterminowe zmiany klimatyczne i ciągle rosnące ceny ropy
naftowej, a także ostatnio zaobserwowany nadmiar produkcji zbóż. Obecnie bioetanol i biodiesel, głównie
wytwarzane z kukurydzy i rzepaku, są stosowane w transporcie. Natomiast w przeszłości rośliny te były
używane tylko jako żywność. W konsekwencji pojawiły się nowe problemy etyczne: rozbieżność między
wykorzystaniem kukurydzy i rzepaku jako żywności lub jako alternatywne źródła energii. Należy podkreślić,
że duże zasoby energii można uzyskać z biomasy pozostałości leśnych, drewna opałowego i szybko rosnących
drzew liściastych, głównie wierzby, topoli i olchy europejskiej. Uprawa pierwszych dwóch wymienionych
gatunków ma już duże tradycje. Nowe podejście biotechnologiczne pokazuje, że rośliny energetyczne mają
również duże znaczenie dla przyjaznego zarządzania środowiskiem, głównie w fitoremediacji, która jest
przedstawiona jako technologia oczyszczania oszczędna i przyjazna dla środowiska. W skrócie
zaprezentowano niektóre dziś używane rodzaje fitoremediacji.
Słowa kluczowe: alternatywne źródła energii, bioetyka, biopaliwa, rośliny energetyczne, ochrony środowiska,
fitoremediacja
Vol. 16, No. 3
2009
Marina V. FRONTASYEVA*1, Sergey S. PAVLOV*, Liguri MOSULISHVILI**
Elena KIRKESALI**, Eteri GINTURI** and Nana KUCHAVA**
ACCUMULATION OF TRACE ELEMENTS
BY BIOLOGICAL MATRICE OF Spirulina platensis
AKUMULACJA PIERWIASTKÓW ŚLADOWYCH
W BIOLOGICZNEJ MATRYCY Z Spirulina platensis
Abstract: A blue-green alga Spirulina platensis biomass is used as a basis for the development of
pharmaceutical substances containing such vitally important trace elements, as selenium, chromium and
iodine. Using neutron activation analysis the possibility of target-oriented introduction of these elements into
the Spirulina platensis biocomplexes retaining its protein composition and natural beneficial properties has
been proved. The curves of the dependence of the introduced element accumulation in the Spirulina biomass
on its concentration in a nutrient medium, which make it possible to accurately measure out the required doses
of the specified element in a substance, have been obtained. The peculiarities of interaction of various
chromium forms (Cr(III) and Cr(VI)) with the Spirulina platensis biomass have been studied. It has been
found that from a nutrient medium its cells mainly accumulate vitally essential form Cr(III) rather than toxic
Cr(VI). Using the EPR technique and colorimetry it has been demonstrated that the Spirulina platensis
biomass enriched with Cr(III) is free from other toxic chromium forms. The developed technique can be used
in pharmaceutical industry for the production of preparations containing Se, Cr, I, etc. on the basis of
Spirulina platensis biomass with the preservation of its natural beneficial properties and protein composition.
Keywords: Spirulina platensis, instrumental neutron activation analysis, essential elements, pharmaceuticals
The investigation of the role of microelements in living systems using modern
biochemical and analytical techniques is a promising direction in Life Sciences. The
results of these investigations can form a basis for a scientifically grounded approach to
the development of new therapeutic and preventive preparations containing such
necessary elements as Se, Cr, I, Zn, etc.
According to the well-known Bertrand diagram [1], for each particular
micro-element there is a certain concentration range of positive effect on the human
organism, with both excess and insufficient concentrations being harmful to the
*
Joint Institute for Nuclear Research, Frank Laboratory of Neutron Physics, 6 Joliot-Curie St.,
141980 Dubna, Moscow Region, Russian Federation, tel. +7(49621) 65609, fax +7(49621)65085
**
Andronikashvili Institute of Physics, Tbilisi, Georgia
1
278
M.V. Frontasyeva, S.S. Pavlov, L. Mosulishvili, E. Kirkesali, E. Ginturi and N. Kuchava
organism. Thus, it is evident that a precise choice of required doses depending on the
purpose of pharmaceuticals is the most important task in designing their substances.
As a rule, in metabolism and exchange processes, microelements are best
assimilated by the organism in a biologically accessible form, ie when they are included
into a biological macromolecule. Hence it follows that it is desirable that as a substance
base we use biologically active biomass, which is capable to assimilate required elements
in prescribed quantities. And, certainly, the choice of biomass should be determined by
its own beneficial therapeutic and preventative properties, as well as by the absence of
harmful impurities in concentrations exceeding permissible levels.
Taking into account the requirements mentioned above, the Adronikashvili Institute
of Physics (Tbilisi, Georgia) in cooperation with the Joint Institute for Nuclear Research
(JINR, Dubna, Russia) developed a technique for production of substances for
therapeutic and preventative preparations on the basis of blue-green algae Spirulina
platensis (S. platensis) [2-5].
Spirulina is a living microorganism and in the process of cell cultivation it is capable
to assimilate certain amounts of some microelements from a nutrient medium and to
incorporate them into the composition of its biological macromolecules. The analytical
control of this process makes it possible to establish a unique dependence between the
element concentration in the nutrient medium and its content in the obtained S. platensis
biomass. This dependence serves as a basis for substantiation of biotechnology for
production of substances for pharmaceutical preparations with required doses of a given
element. It is very important that concentrations of compounds added to the nutrient
medium as loading, have no influence on the conditions, in which spirulina cells grow
normally and retain their beneficial natural properties. That is why, along with the
analytical control, the protein composition of the obtained biomass was investigated by
the gel-electrophoresis technique.
Biotechnology of target-oriented incorporation of certain elements into S. platensis
biomass composition in the process of cultivation, was developed using as an example
such vitally important elements as Se, Cr and I.
Selenium. The studies of the role of selenium in the human organism over the last
20 years showed it to be such an important element that it was named the element of the
century at the 7th International Symposium «Selenium-2000» (Venice, October 2000).
Selenium is a normal component of some enzymes, proteins and amino acids. Its low
level in the organism raises the risk of such diseases as cardiomyopathy, cancer, endemic
osteoarthropathy, anaemia, etc. [6, 7]. The functions of Se are closely related to vitamin
E and beta carotene (which are contained in S. platensis biomass), therefore in the
treatment they are sometimes used in combination. Selenium contributes to the reduction
of harmful effects of free radicals and also allows detoxification of the organism from
such elements as As, Hg, Cd, Bi, etc. It participates in photochemical reactions related to
vision, can influence the immune and endocrine systems, etc. Selenium added to diet in
particular doses slows down the ageing processes, favours treatment of cardiological
patients and reduces the risk of cancer and AIDS [8, 9].
Iodine. Another equally important element incorporated in the composition of all
living organisms and plants is iodine. It is vitally important for their development, growth
and functioning. Iodine intake by the organism strongly depends on the state of the
environment and its deficiency often has an endemic character. Iodine influences
Accumulation of trace elements by biological matrice of Spirulina platensis
279
metabolism and enhances reduction-oxidation processes, thus iodine deficiency can
affect the physical, mental and emotional state of the organism. Among serious
symptoms and results of iodine deficiency are cardiological diseases (atherosclerosis,
vessel deformation, etc.), immunodeficiency (susceptibility to infections and colds),
emotional disturbance (irritability, sleepiness, etc.), mental disorders (deterioration of
memory, low level of intellectual development - low IQ, cretinism and others) [10].
Unfavourable ecological situation and lowering of living standards of population in
many countries of the world, as well as studies on the assessment of iodine deficiency at
the level of populations have put this problem among UN priorities in the sphere of
human health.
Chromium. Chromium interaction with S. platensis biomass is of special interest. Cr
is known to be a vitally important trace element, which possesses, at the same time,
significant toxic properties. It exists in various valence states (from +2 to +6) and forms
numerous complex compounds, most stable of which are Cr(III) and Cr(VI). Kinetically
stable, non-toxic Cr(III) is most abundant in the environment. Toxic Cr(VI) penetrates
cells easier than Cr(III), participates in the reduction-oxidation processes inside them,
thus reducing to the stable Cr(III). These processes cause damage of cell genetic
material, oxidative injuries, formation of cross-links and thus, have carcinogenic,
genotoxic and mutagenic effects [11].
On the other hand, chromium is a necessary chemical element without which normal
functioning of the organism, is impossible. The most important function of chromium is
control of sugar. It is known to be the key constituent in the so-called glucose tolerance
factor. Cr contributes to insulin participation in metabolism of hydrocarbons (proteins,
lipids, nucleic acids) and to effective transfer of glucose into tissue cells. It also
influences the synthesis of macromolecules, activation of some enzymes and cholesterol
metabolism [12, 13].
The deficiency of Cr in the human organism results in the derangement of lipid and
fat metabolism, in depressed physical growth and in weight loss, decreased longevity and
impaired coordination of movements. Sometimes chromium deficiency is associated with
high cholesterol levels, tiredness and fatigue, alcoholic intolerance, etc. The Cr
deficiency most often becomes apparent in early childhood and young age through
disturbed protein metabolism. In all the above-listed cases the addition of Cr into the diet
helps to treat the diseases. Thus, the task to produce chromium-containing
pharmaceuticals designed to eliminate Cr deficiency, is an urgent question.
Material and methods
The strain IPPAS B-256 of S. platensis from the algeological collection of the
Timiryazev Institute of Plant Physiology of RAS was used in the experiments. To
stimulate growth, the spirulina culture was previously slightly treated in Potter
homogenizer in order to partly shorten its threads. The cultivation of S. platensis cells
was carried out in the Zaroukh standard water-salt nutrient medium at pH 8.5÷11, at
a temperature of 32÷34°С, continuous stirring and illumination with 5000 lx sodium
lamp.
The nutrient medium was prepared in two stages: the corresponding chemical
compound containing the element to be introduced (Se, Cr, I) was added as a loading
280
into the first part of the solution containing NaHCO3, K2HPO4⋅3H2O and Na2CO3 at
pH < 10, then this solution was mixed with the second part of the solution, containing all
remaining components [4, 5]. This method ensured intensive inclusion of a required
element into spirulina biocomplexes with the preservation of its natural beneficial
properties.
To study elements accumulation dynamic in the S. platensis biomass cultivation was
carried out in a nutrient loading with concentrations ranging:
for selenium - selenious acid H2SeO3 - from 0.5 to 15 mg/dm3
for iodine - potassium iodine KI - from 10–8 to 10–4 g/dm3
for chromium - Cr(III) - chromium acetate Cr(CH3COO)3
The investigation of dynamics of S. platensis biomass growth in the selected mode
demonstrated that the maximal growth occurred in 5-6 days (Fig. 1). In the preliminary
experiments, a range of permissible loading concentrations in the nutrient medium was
also determined, at which a required dose of a given element in biomass was provided
with the retention of its quality.
Fig. 1. Curve of growth of Spirulina platensis biomass
In each experiment, after cultivating for 5 days, the harvest of S. platensis biomass
was separated from the nutrient medium by filtering, rinsing and centrifugation. The
resulting substance was lyophilically dried in a special adsorption-condensation
lyophilizer of an original design [14].
The protein content in the obtained biomass was found (by Lowry technique [15]) to
be about 65% and corresponded to a normal level typical for natural S. platensis
biomass. The quality of biomass was also confirmed by comparison of
281
electrophorograms obtained by gel electrophoresis technique for samples grown with and
without loading.
Samples for analysis were prepared in the form of small pellets using a special
titanium mould. Neutron activation analysis (NAA) using epithermal neutrons,
a well-proven technique for determination of element composition of biological objects,
was used as an analytical technique. Due to resonance neutron activation, the technique
makes it possible to minimize matrix effects of biological samples and at the same time
to determine concentrations of over 30 major, minor and trace elements.
Analytical research was conducted at the IBR-2 fast pulsed reactor of the Frank
Laboratory of Neutron Physics JINR (Dubna, Russia). Experimental techniques and
analytical information treatment procedure are described in [16, 17].
First, the multielement composition of S. platensis biomass was studied by the NAA
technique and the concentrations of certain elements were compared with the
corresponding permissible level values [2]. The results of the investigations showed that
the concentrations of such toxic elements as As, Hg, Cd, Pb, etc. do not exceed those
permissible for the human organism, according to the data at the website:
http://www.spirulina.com/SPBNutrition.html.
Results and discussion
Selenium. Selenious acid H2SeO3 of various concentrations in the range of
0.016÷2770 µg/dm3 was used as a loading of the nutrient medium to obtain
selenium-containing S. platensis biomass. The results of determination of Se
concentration by the NAA technique are shown in Figure 2. As can be seen from this
figure, the curve of Se content in biomass versus its concentration in the nutrient medium
is well approximated by a polynomial of the 2nd order y = −0.00008x2 + 0.3x – 1.
Starting from Se concentration of 100 µg/dm3, an intensive growth of its accumulation by
cells with a possible maximum in the range of 1100÷1200 µg/dm3 is observed. For
pharmaceutical purposes, the range 100÷1000 µg/dm3 seems to be the most
advantageous: at high degree of Se assimilation the significant steepness of the curve
enables rather exact determination of its doses in a substance obtained.
Visual microscopic observation of the state of culture, determination of total protein
content in the biomass as well as investigation of its electrophorograms revealed natural
properties of the obtained selenium-containing biomass. Thus, by including Se in the
composition of its biological macromolecules, S. platensis preserves its beneficial
properties and compares favourably with other similar preparations, which are either
a mechanical mixture of Se compounds with spirulina powder [18] or are obtained at
such high Se concentrations in a medium that cells grow on the background of struggle
for survival and no normal quality of biomass can be retained [19].
Chromium. Chromium-containing S. platensis biomass with vitally essential form
Cr(III) was cultivated at the loading of the nutrient medium with chromium acetate
Cr(CH3COOH)3 in concentrations from 0.5 to 15 mg/dm3 (Fig. 3). The accumulation of
toxic Cr(VI) form by spirulina at loading of the nutrient medium with potassium
bichromate K2Cr2O7 in the similar range of concentrations (Fig. 3) was also investigated.
As can be seen from the curves obtained, spirulina assimilates mainly Cr(III), while the
degree of binding of Cr(VI) is approximately three times lower. As opposed to other
282
microorganisms, such as, for example, Arthrobacter оxydans, S. platensis prefers a nontoxic form of chromium to the toxic one, even if both forms are present in the solution.
Fig. 2. Selenium in Spirulina platensis biomass versus its content in a nutrient medium
Fig. 3. Observed chromium concentrations in Spirulina platensis biomass at different concentration
levels of Cr(III) and Cr(VI) in the growth medium respectively
283
Due to the fact that some microorganisms in the process of metabolism can interact
with a number of elements and change their valence, it was necessary to verify whether
under loading of the nutrient medium with Cr(III) compounds a toxic form Cr(VI) arises
in the possible chain of its valence change Cr(III) → Cr(V) → Cr(VI) or not. For this
purpose, the technique of colorimetric determination of Cr(VI) was applied using
diphenylcarbohydrazide (C6H5NHNH)2CO, which reacts with Cr(VI) in concentrations
of 0.1÷10 µg/dm3 to give a purple-red colour and yields a photometric peak at
λ = 540 nm [20]. The investigations showed that Cr(VI) was absent in all cases of
S. platensis cultivation with Cr(III) loading.
The presence of intermediate form Cr(V) was checked by the electron paramagnetic
resonance (EPR) technique with a sensitivity of the order of 5⋅10–10g of Cr(V). The
obtained results showed the absence of a resonance signal, which is typical for Cr(V), in
all samples under investigation.
It can be seen from Figure 3 that at loading concentrations within 5÷12 mg/dm3, the
curve of Cr(III) accumulation in S. platensis biomass does not reach its saturation level.
This makes it possible to obtain optimal chromium doses in the resulting biomass and to
recommend 30÷100 µg/dm3 for food supplement and 200÷250 µg/dm3 for therapeutic
and prevention purposes [5].
Iodine. Iodine-containing S. platensis biomass was cultivated in the nutrient medium
with loading of potassium iodide KI in the concentration range of 10–8÷10–4 g/dm3.
The curve of iodine concentration in biomass versus its concentration in
the nutrient medium (Fig. 4) can also be approximated by the 2nd order polynomial
y = 0.00001x2 – 0.003x + 0.4.
Fig. 4. Iodine in Spirulina platensis biomass versus its content in a nutrient medium
The biomass enrichment coefficient can be defined as a ratio between the iodine
(or other element) concentration in the biomass and the iodine concentration in the
nutrient medium in accordance with the curve obtained. This coefficient may serve as an
284
initial technological parameter governing the element dosage in treatment pills and the
choice of the pill mass for a given substance. For iodine, it is possible to produce pills
5 mm in diameter, of mass 0.5 g and with iodine content of 100÷200 µg.
The microscopic control of cytological state of the culture as well as of protein
content of the obtained biomass demonstrated in all cases that the normal state of
S. platensis and, consequently, its natural beneficial properties are retained.
Conclusion
The performed investigations demonstrated that the cultivation of S. platensis cells
under selected conditions allows target-oriented introduction of the required elements
(Se, Cr, I, etc.) into the composition of biological macromolecules with preservation of
their protein composition and natural properties of biomass. With the application of
NAA the curves of concentrations of necessary elements in the resulting S. platensis
substance versus concentrations of these elements in the nutrient medium were obtained.
The possibility of accurate determination of therapeutic and preventative doses of each
element according to these curves was demonstrated.
The results of NAA-analysis of multielement composition of S. platensis biomass
and their comparison with the permissible level demonstrated that the content of such
toxic elements as Hg, Cd, As, etc. does not exceed the permissible level accepted in
many countries of the world.
The developed technique can also be used for production of substances with
introduction of other vitally important elements such as Zn, Cu, Fe and others.
References
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
Mertz W.: Science, 1981, 213, 1332-1338.
Mosulishvili L.M., Kirkesali Ye.I., Belokobylsky A.I., Khizanishvili A.I., Frontasyeva M.V., Pavlov S.S.
and Gundorina S.F.: J. Pharm. Biomed. Anal., 2002, 30(1), 87-97.
Mosulishvili L.M., Belokobylsky A.I., Kirkesali E.I., Frontasyeva M.V., Pavlov S.S. and Aksenova N.G.:
J. Neutron. Res., 2007, 15(1), 49-54.
Mosulishvili L.M., Belokobylsky A.I., Khizanishvili A.I., Kirkesali E.I., Frontasyeva M.V. and Pavlov
S.S.: Patent of RF No. 2209077, priority of March 15, 2001.
Mosulishvili L.M., Belokobylsky A.I., Kirkesali E.I., Frontasyeva M.V. and Pavlov S.S.: Patent of RF
No. 2230560, priority of June 11, 2002.
Combs G.F. Jr.: Med. Klin., 1999, 3, 18-25.
Schumacher K.: Med. Klin., 1999, 3, 45-48.
Hobben D.H. and Smith A.M.: J. An. Diet. Assoc., 1999, 99(7), 836-851.
Clark L.C., Cantor K.P. and Allaway W.H.: Arch. Environ. Health, 1991, 46, 37-42.
Voinar A.I.: Trace elements in nature. Vysch. shkola (Higher Education), Moscow 1962 (in Russian).
Liu K.J., Husler J., Ye J., Leonard S.S., Cutler D., Chen F., Wang S., Zhang Z., Ding M., Wang L. and
Shi X.: Mol. Cell. Biochem., 2001, 222, 221-229.
Anderson R.A.: [In:] Essential and toxic trace elements in human health diseases. Ed. A.S. Prasad and
A.R. Liss. New York 1988, 189-197.
Mertz W.: [In:] Chromium in nutrition and metabolism. Ed. D. Shapcott and Y. Hubert. Elsiever/North
Holland Biomedical Press, Amsterdam 1979, 1-14.
Mosulishvili L.M., Nadareishvili V.S., Kharabadze N.E. and Belokobylsky A.I.: Patent USSR. N779765,
Bull. 42, 1980.
Practical training on biological chemistry. Eds. M.P. Meshkova and S.E. Severin, MSU Publ. 1979 (in
Russian).
Frontasyeva M.V. and Pavlov S.S.: JINR Preprint E14-2000-177, Dubna 2000.
285
[17] Ostrovnaya T.M., Nefedyeva L.S., Nazarov V.M., Borzakov S.B. and Strelkova L.P.: [In:] Activation
analysis in environmental protection. Dubna, D-14-93-325, 1993, 319-326.
[18] Hann M. and Stemgel H.: Patent of DE 3421644. 12.12.85. Diatetische Zusammensetzung.
[19] Tambiev A.H., Kirikova N.N., Mazo V.K. and Skalny A.V.: Patent, RU2096037.20.11.97, 1997.
[20] Urone P.F.: Anal. Chem., 1955, 27(13), 1354-1355.
AKUMULACJA PIERWIASTKÓW ŚLADOWYCH
W BIOLOGICZNEJ MATRYCY Z Spirulina platensis
Abstrakt: Biomasa niebiesko-zielonych glonów Spirulina platensis jest wykorzystywana jako główny
składnik opracowywanych preparatów farmaceutycznych zawierających takie niezwykle ważne pierwiastki
śladowe, jak selen, chrom i jod. Udowodniono, wykorzystując neutronową analizą aktywacyjną, możliwość
sterowanego wprowadzenia tych biopierwiastków do biokompleksu ze Spiruliną platensis, zachowując skład
jej białka oraz korzystne właściwości fizyczne. Krzywe zależności akumulacji wprowadzanego pierwiastka
w biomasie Spiruliny do jego stężenie w pożywce, umożliwiają dokładny pomiar obecnie wymaganej dawki
określonych pierwiastków w otrzymanym preparacie. Badano wpływ różnych stopni utlenienia chromu (Cr(III)
i Cr(VI)) na biomasę Spirulina platensis. Stwierdzono, że w komórkach glonów akumulowała się z pożywki
głównie niezbędna dla życia forma Cr(III), a nie toksyczna Cr(VI). Korzystając ze spektrometrii EPR oraz
kolorymetrii, wykazano, że biomasa Spiruliny platensis wzbogacona formą Cr(III) jest wolna od toksycznych
form chromu. Opracowana technika może być wykorzystana w przemyśle farmaceutycznym do produkcji
preparatów zawierających selen, chrom i jod itp. z biomasy Spiruliny platensis, z zachowaniem jej
korzystnych właściwości fizycznych i składu białka.
Słowa kluczowe: Spirulina platensis, instrumentalna neutronowa analiza aktywacyjna, mikroelementy
niezbędne, środki farmaceutyczne
Vol. 16, No. 3
2009
Waldemar WARDENCKI*1, Tomasz CHMIEL*, Tomasz DYMERSKI*
Paulina BIERNACKA* and Beata PLUTOWSKA*
APPLICATION OF GAS CHROMATOGRAPHY,
MASS SPECTROMETRY AND OLFACTOMETRY
FOR QUALITY ASSESSMENT
OF SELECTED FOOD PRODUCTS
ZASTOSOWANIE CHROMATOGRAFII GAZOWEJ,
SPEKTROMETRII MAS I OLFAKTOMETRII
W OCENIE JAKOŚCI WYBRANYCH PRODUKTÓW SPOŻYWCZYCH
Abstract: The volatile compounds in spirits and honeys were determined by headspace solid-phase
microextraction as sample preparation technique and gas chromatography (GC) with mass spectrometry (MS)
and olfactometry (O) detection. Identification of spirits and honey volatiles was made by comparison mass
spectra with data in NIST Mass Spectral Database. Additionally, flavour compounds detected by sensorypanel were registered in the form of olfactograms by fingerspan method. Analysis of raw spirits indicated the
presence of over 200 compounds, of which a significant number were identified (including esters, higher
alcohols, aldehydes, acetals, as well as furanes, sulphur compounds, terpenoids and benzene derivatives).
Among them over 50 were identified whose presence or high content can decrease the quality of distillates. In
the result of performed analysis of honeys, 163 volatile and semi-volatile compounds were identified (aliphatic
and aromatic acids, aldehydes, ketones, alcohols and phenols, terpenoids, furane and pyrane derivatives). In
the midst of them markers of each type of honeys were indicated. Formed determinant lists can be useful for
distinguish and quality control (for example finding adulterations) of Polish honeys. Besides, application of
GC-MS technique coupled with olfactometry make possible creating aroma profiles of investigated honeys.
Employed techniques were characterized by high sensitivity and repeatability, furthermore they are less timeconsuming.
Keywords: volatile compounds, aroma, raw spirits, honeys, solid-phase microextraction, gas chromatography,
mass spectroscopy, olfactometry
Volatile (odorous) compounds perform a vital role in shaping the organoleptic
quality of many food products [1-3]. For consumers, an organoleptic quality is equally
important and often decisive in the purchase. From chemical point of view, the aroma of
*
Chemical Department, Gdansk University of Technology, ul. G. Narutowicza 11/12,
80-233 Gdańsk-Wrzeszcz
1
288
Waldemar Wardencki, Tomasz Chmiel, Tomasz Dymerski, Paulina Biernacka and Beata Plutowska
most food products is a complicated mixture, sometimes consisting of several hundred
compounds. The analysis of aroma, ie the presence, content and composition of volatile
substances, can constitute a valuable source of information on the health quality of food.
A classical approach to the evaluation of organoleptic quality is based on the
exploitation of sensory analysis, carried out by a group of trained assessors. This analysis
is a perfect tool in carrying out marketing tests of consumers but because of great human
participation it has many limitations [4]. Because of these deficiencies a good
supplement of the evaluation of organoleptic food properties is instrumental analysis.
Appropriate instrumental methods allow a detailed and complex qualitative and
quantitative analysis of volatile components, which influence on the flavour composition
of food products [5]. The methods employed most often, allowing the creation and
recognition of aromagrams are chromatographic techniques, in particular gas
chromatography and so called electronic nose [6-9].
In recent years, intensive studies have been carried out regarding sensory activity of
the individual volatile components of various food products and the dependence between
the odour and the chemical composition of the volatile fraction of these products, using
gas chromatography with olfactometric detection (GC-O) [10-12].
The purpose of this work was identification and comparison of volatile compounds
present in headspace fraction of different raw agriculture spirits and honeys of different
origin and attempt finding the relation between flavour compounds content and quality of
these products.
Materials and methods
Investigated objects
Raw spirits
For this study 39 samples of raw grain spirits with an ethanol concentration of
approximately 90% (v/v) were collected from local agricultural distilleries (Pomeranian
province). All the samples, divided into three groups after the sensory analysis in
accordance to Polish Standard PN-A-79528-2:2002, were investigated. The first
13 samples did not fulfil the Polish Standard demands. Following 13 samples obtained
divergent evaluation marks. Some of the panelists reckoned them in accordance, some
others without accordance to Polish Standard demands. The last group of 13 samples
fulfilled Polish Standard requirements and obtained the highest organoleptic quality
assessment.
High purity water (MilliQ A10 Gradient/Elix System, Millipore; Bedford, MA,
USA) as well as standard substances and alkanes with a chain length from C5 to C20
(Sigma-Aldrich Poland, Steinheim, Germany) were also used in the research.
Honeys
Investigation was performed for 40 samples of several popular unifloral Polish
honeys (8 samples for each type), namely: acacia (A), buckwheat (B), lime (L),
honeydew (H) and rape (R). Honey samples satisfied quality requirements of
PN-88/A-77626. Rest of reagents was identical like in case spirit analysis.
Application of gas chromatography, mass spectrometry and olfactometry for quality …
289
Sample preparation (Headspace solid phase microextraction)
Raw spirits
Raw spirits were diluted with water to an ethanol concentration of 20% (v/v). 8 cm3
of sample were placed in a 15 cm3 vial with magnet stirring bar and capped with teflon
lined septa. During extraction the temperature of the vial was kept at 45°C, and the
sample was stirred (700 rpm) without the addition of salt. The SPME-fiber
(DVB/CAR/PDMS, 50/30 µm, 2 cm) was inserted for 40 min into the headspace of the
vial and immediately after the end of extraction placed in the injection port of the GC for
5 min for thermal desorption of the analytes.
Honeys
Weighed amount of honey (approx. 2.5 g) was placed in 15 cm3 vial with 0.5 cm3
water addition in order to receive homogeneous solution, then volatile compounds were
easier and faster crossed over to headspace. The vials were closed by PTFE/Silicone
lined septa to prevent loosing volatiles. To ensure phase equilibrium, samples were kept
at 60°C for 10 min. The SPME-fiber (like in case raw spirits) was exposited at the same
temperature for 40 min. Afterwards fiber was put into the GC injection port for 5 min at
250°C for quantitative desorption of the analytes. Isolation and pre-concentration stage
was supported by agitation (850 rpm).
Separation and detection (Gas chromatography)
A TRACE GC 2000 (Thermo Finnigan, Waltham, MA, USA) gas chromatograph
equipped with a split/splitless injector, an olfactometric detector (Sniffer 9000 System,
Brechbühler, Houston, TX, USA) and a TRACE DSQ quadrupole mass spectrometer
was used for identification of extracted volatiles. Separation was achieved on two
different columns for raw spirits analysis and one for honeys. Columns parameters were
as follows: Stabilwax-DA (Restek, Bellefonte, PA, USA) polar capillary column with
a modified polyethylene glycol bonded phase (30 m x 0.32 mm I.D., 0.5 µm film
thickness) and HP-5MS (Agilent Technologies, Santa Clara, CA, USA) non-polar
capillary column with a (5%-diphenyl/95%-dimethyl)-polysiloxane bonded phase (30 m
x 0.25 mm x 0.25 µm). The first one was used for both, raw spirits and honeys, whereas
the second only for agricultural distillates. The Stabilwax-DA column temperature
program for raw spirits was as follows: 45ºC held for 1 min and then ramped up
6ºC min–1 to 120ºC, then increased 5ºC min–1 to 180ºC and once again ramped up
8ºC min–1 to 240ºC and held for 7 min in this temperature. The total runtime was 40 min.
For honey different oven program was applied: starting temperature was 50ºC for 1 min,
next temperature increased 5ºC min–1 up to 200ºC, then grown 10ºC min–1 to 240ºC and
held for 15 min in this temperature. The total runtime was 10 min longer than in spirits
analysis. The initial oven temperature for the HP-5MS column program was
40ºC held for 10 min and then ramped up 3ºC min–1 to 120ºC, and once again ramped up
10ºC min–1 to 250ºC with a final isothermal period of 5 min. The total runtime was
55 min. The temperature of the injector was 250ºC in both cases. The carrier gas was
helium with a flow rate of 1.5 cm3 min–1(raw spirits) and 2.2 cm3 min–1 (Stabilwax-DA
column) or 1 cm3 min–1 (HP-5MS column). Additionally auxiliary gas - moist nitrogen
290
(flow rate - 12.5 cm3 min–1) was used in order to prevent drying up nose mucous sensory
evaluator. The detector operated in electron impact mode (70 eV) at 240ºC. The transfer
line temperature was 240ºC. Detection was carried out in scan mode in a range of
m/z 40÷400. For better characterization of volatile fraction the analysis were carried out
with the use of two detectors: olfactometric and mass spectrometer.
Results
Raw spirits
The chromatograms for a typical agricultural distillate sample with a low
organoleptic quality analyzed on two columns (non-polar HP-5MS and polar
Stabilwax-DA) are presented in Figure 1. The raw spirits volatile fraction analysis
indicated the presence of over 200 compounds of which a significant number were
identified. Identification was achieved with using various methods, but most importantly
on the basis of comparing their mass spectrums with spectrums available in the NIST
spectrum library. In addition, retention indexes were also calculated with the use of
a homologous series of alkanes with a chain length from C5 to C20. The identification of
some of the compounds was additionally confirmed by the consistency of their retention
indexes with values in literature, as well as on the basis of uniformity of retention times
and mass spectra with standard substances.
Fig. 1. Typical chromatograms of a raw spirit volatile fraction obtained using: a) non-polar HP-5MS
and b) polar Stabilwax-DA columns
291
With the aim of determining the dependence between the composition of the volatile
fraction of a product and its sensory quality, studies were conducted which were to make
possible the discovery of differences in the composition of the volatile fractions of aroma
compounds in agricultural distillates with different organoleptic quality. For the analysis,
raw spirits were chosen which differed in evaluations obtained during the sensory
analysis - 13 samples which obtained a high evaluation and fulfilled Polish Standards
requirements, 13 samples which obtained a low evaluation and were deemed to not meet
required Polish Standards by a portion of the panel as well as 13 samples, which did not
fulfill standard requirements and did not qualify for further rectification and the
production of spirits.
In the results of the conducted studies, over 100 compounds were identified which
appeared in distillates with a low organoleptic quality, which fulfilled the requirement
that the peak surface area of a given compound on a low quality sample’s chromatogram
is larger than any peak surface area of the same compound on chromatograms for
samples with a high organoleptic quality. Table 1 presents a list of selected exemplary
compounds (their retention indexes and references), whose high content or presence
could be the cause of poor quality of distillates. The fragment ions masses used during
peak integrations are given in brackets. For confirmation of this statement, olfactometric
detector and Stabilwax-DA capillary column were used. The GC-O analysis combined
with GC-MS analysis allowed for identification some of the flavours which are the cause
of decreasing quality. Identified flavours appeared most often in raw spirits samples are
listed in Table 2. Odours were identified by comparison of the retention times obtained
by GC-MS and GC-O. Empirical aroma description was compared with the literature
aroma description for confirmation of identified compounds. The olfactometric analysis
has shown that in spite of similarities in volatile fraction composition some relationships
in raw spirits quality were observed. Performed studies revealed the most general
conclusion: the richer the profile of the volatile compound is, the lower the quality of the
distillate. Despite the fact that practically every sample contains a unique set of volatile
compounds, a few relationships were observed between the chemical composition of
a distillate sample and its sensory properties. These conditions relate most of all to
a higher content of compound groups, such as acetals and esters, as well as two
compounds, dimethyl trisulfide and geosmin (2β,6α-dimethylbicyclo[4.4.0]decan-1β-ol).
Except for the above-mentioned compounds, the composition of the volatile fraction of
distillates with a low quality also includes aldehydes, terpenes, thiophene, furan or
guaiacol derivatives, xylenes as well as a very large group of other identified and
unidentified pollutants. Most of the discussed components are counted as aroma
compounds, and some, such as dimethyl trisulfide and geosmin, are characterized by
a very low sensory threshold. These compounds were confirmed by GC-O analysis as
those which decreases quality of raw spirits samples the most. The results obtained with
the use of two detectors were in good correlation. Dimethyl trisulfide’s aroma is
described in literature as a spoiled food-type smell, spoiled cabbage, garlic, onion-like,
musty, sulphuric, pungent. This compound was identified in beverages such as wine,
tequila and Yanghe Daqu (a Japanese wheat-based alcoholic beverage), and its sensory
detection limit in a 10% ethanol-water solution was 0.2 µg dm–3 [18, 25-27]. Geosmin is
a compound with an earthy and musty aroma, which is detectable practically in
ultra-trace quantities - its detection limit in wine is 60÷90 ng dm–3 [28]. Both compounds
292
are not typical fermentation products and are volatile metabolites produced by different
undesirable microorganisms, such as fungi or many types of Actinomycetes, which
develop in raw materials or as a result of infections during the fermentation process.
From the conducted studies, it appears that their increased content in agricultural
distillates significantly correlates with sensory analysis results and in most cases is even
a disqualifying attribute. All of the distillates with the worst sensory properties, except
for sample number 13, contain a significantly high quantity of at least one of these
compounds. Whereas dimethyl trisulfide appears in small quantities in both, high and
medium quality spirits, the geosmin peaks appear only on chromatograms for the
worst-quality distillates (GC-MS detection). However GC-O detection was characterized
by higher sensitivity for geosmin than GC-MS detection. Olfactometric detection
revealed that geosmin was detected in every medium and low quality samples. Even trace
quantity of geosmin and dimethyl trisulfide found in raw spirits influence on the quality
of rectified spirits as well as alcoholic beverages obtained from them.
Table 1
Selected compounds considered as responsible for decreasing organoleptic quality of raw spirits samples
Retention Indexes
HP-5MS Stabilwax-DA
<500
713
613
906
648
935
658
935
704
870
726
906
859
991
864
1162
864
1168
875
1010
931
1035
960
1086
961
1083
964
1412
977
1116
978
1106
1002
1252
1057
1265
1097
1244
1158
1486
1208
1462
1269
1565
1399
1680
1467
1692
1483
NF
1599
NF
1862
1882
Compound
Acetaldehyde* (43)
Ethyl acetate* (61)
3-Methylbutanal* (58)
2-Methylbutanal (58)
1-Ethoxy-1-butene (57)
1,1-Diethoxyethane* (45)
1,1-Diethoxy-2-methylpropane (103)
p-Xylene* (106)
m-Xylene* (106)
1-(1-Ethoxyetoxy)-2-methylpropane (73)
α−Pirene* (93)
1,1-Diethoxy-3-methylbutane (103)
1,1-Diethoxy-2-methylbutane (103)
Dimethyl trisulfide* (126)
1-(1-Ethoxyethoxy)-3-methylbutane (73)
1-(1-Ethoxyethoxy)-2-methylbutane (73)
Ethyl hexanoate* (88)
γ-Τerpinene* (93)
1,1-Diethoxyhexane (103)
2-Pentyl thiophene (97)
Ethyl octanoate*(88)
2-(1,2-Diethoxyethyl)-furan (125)
Ethyl decanoate* (88)
7,11-Dimethyl-3-methylene-1,6,10dodecatriene (69)
2-Methyl-6-p-tolyl-2-heptene (119)
Geosmin* (112)
Ethyl dodecanoate* (88)
References
IRnon-polar
435 [13]
615 [13]
649 [15], 650 [13]
658 [15], 660 [16]
IRpolar
718 [14]
902 [14]
936 [14]
726 [17,18]
859 [18]
861 [15], 864 [19]
860 [20]
931 [20]
955 [10]
1045 [14]
970 [21], 972 [22]
1003 [20]
1058 [20]
1274 [14]
1199 [20]
1398 [20]
1459 [23], 1466 [24]
1711 [14]
1597 [20]
* - identification confirmed on the basis of uniformity of retention times and mass spectra with standard
substances
293
Table 2
Identified odours during GC-O analysis
Odour description
sweet, fruity
sweet, musty, aldehydic
sweet, rum
sweet, synthetic
sweet, fruity, pineapple
vegetable, boiled cabbage, onion
sweet, fruit drop, fruity *
sweet, fruity
sweet, cheesy, musty *
sweet, fruity, pineapple *
sweet, unpleasant, sickening
sweet, acidulous
fresh, citrus, sweet
pungent, synthetic
vegetable, boiled cabbage, boiled onion *
sweet, plastic, synthetic
sweet, pungent, citrus, fruit drop *
green, peas, grass *
bread peel, synthetic *
pungent, bread peel
cabbage
synthetic, bread peel *
bread peel, pungent *
green, geranium
musty, pungent
green tea, citrus
mould-ripened cheese
green, floral *
sweet, pungent *
unpleasant, mousy, animal *
green, floral, geranium
medicine, vitamin, boiled chicken *
fresh, wet soil, geranium, green *
boiled cabbage, vegetable
musty
flowery, sweet champagne *
green, sweet, pungent *
wet basement, mouldy, musty, wet soil *
pungent, aniseed *
creamy, processed cheese
almond, synthetic
floral, green, geranium
Compound name
ethyl acetate + 1,1-diethoxyethane
2-methylbutanal + 3-methylbutanal
ethyl propionate
2-methylpropyl acetate
ethyl butyrate
dimethyl disulfid
2-methyl-1-butyl acetate + 3-methyl-1-butyl acetate
2-methyl-1-butanol + 3-methyl-1-butanol
ethyl hexanoate
dimethyl trisulfide
ethyl octanoate
ethyl decanoate
acetic acid phenylethyl ester
ethyl dodecanoate
geosmin
* - odours which appeared most often in aroma profiles
Honeys
Figures 2A and 2B presents typical honey chromatograms analysed by developed
methodology. At the first look, obtained volatile profiles of particular honey types differ
each other. The most characteristic chromatograms were received for buckwheat and
lime honeys.
294
Fig. 2. Comparison of chromatograms - five samples of honey types: A) full profile, B) exemplary
variety markers lime honey: 1 - limonen, 2 - 2-methylbutanol + 3-methylbutanol,
3 - phellandrene
295
Compounds in volatile fraction were identified by comparison of mass spectra with
data in NIST Mass Spectral Data Base (like spirit samples). Identity of chosen volatile
compounds was additionally verified on the basis of conformity of retention times and
mass spectra with standards. In result, 163 volatile and semi-volatile compounds
(aliphatic and aromatic acids, aldehydes, ketones, alcohols and phenols, terpenoids,
furane and pyrane derivatives) [29, 30] were identified from which the characteristic
compounds for each honey variety were indicated.
Fig. 3. Selected variety of honey markers: bukwheat (B), lime (L), acacia (A), rape (R), honeydew
(H)
Figure 3 presents 23 from 163 identified compounds of Polish honeys. It can be seen
that some compounds were found in two, three, four or even in all honey varieties, for
example benzyl alcohol, furfural. On the other hand, some compounds were present in
only one type of honey suggesting that they can be the markers, eg buckwheat
honey determinant can be pentanal, acacia hexanal and lime p-methylacetophenone.
296
Absence in only one type of honey have suggested that given compound can be a marker,
eg 2-ethylhexanol for buckwheat honey, methylbutanal (two isomers) for honeydew [30]
and p-cymene for rape variety. It is worth to notice that lilac aldehyde that was not
existed in a few honey types (acacia, rape and honeydew) can be honeydew marker, in
case of absence of all isomers in this type of honey. Furfural and methylbutanal [30] were
found in buckwheat honey in five and seven times greater quantity than in the rest of
honey types. The same situation was with p-cymen existing sevenfold greater in lime
honey. It can allow for distinguishing honey varieties in respect of this characteristic
amount. Like in spirits samples, Kovats retention indexes, useful information in
comparing interlaboratory results [30], were calculated and are shown in square brackets
in Figure 3.
Table 3
Selected flavour compounds identified in the investigated honeys.
RTGC-MS RTGC-O
Compound name
A B L H R
1.22;
1.71 methanethiol + acetaldehyde + + + + +
1.28
1.40
1.91
2.37
3.07
3.11
3.91
4.32
5.24
9.36;
9.41
10.91
dimethyl sulfide
2-methylbutanal + 3methylbutanal
2,3-butanedione
3-methylbutanoic acid ethyl
ester *
+ + + + +
-
+
-
+
-
+ + + + +
-
+
-
-
-
10.58
acetoin + octanal
12.06
rose oxide
11.78
12.98
dimethyltrisulfide
12.02
13.18
nonanal
13.30
14.05
15.59
15.65
14.42
15.19
16.74
16.80
16.16
17.38
dimethylstyrene *
furfural
benzaldehyde
linalol
3,9-epoxy-p-mentha-1,8(10)diene *
17.21
18.36
hotrienol *
18.36
19.56
phenylacetaldehyde
+ + + + +
18.88
19.96
benzoic acid ethyl ester
+ + + + +
22.08
23.24
beta-damascenone
+ + + + +
23.31
24.02
26.94
24.63
25.23
28.05
benzyl alcohol
2-phenylethyl alcohol
p-anisaldehyde
+ + + + +
+ + + + +
+ + + + +
30.30
31.41
3-aminoacetophenone
+ + + + +
Aroma description
acrid, faint, cooked cabbage, addled
eggs, acetic
sweet, honey, acrid, cooked vegetables,
sulphuric
sweet, almond, fermented, apple,
cheese
sweet, butter, cream
sweet, acetic, strawberry, raspberry
juice
+ + + + + sweet, tart, orange skin, sweety, cream
-
+ + +
-
sweet, acrid, tart, fragrant
sulphuric, vegetable, cooked cabbage,
+ + + + +
onion, rotten
synthetic, gummous, wax, mouldy,
+ + + + +
starched
+ + + + +
acrid, horseradish, anise
- + - - sweet, fruit, cherry, soft almond
- + - + sweet, almond, marzipan
+ + + + sweet, citrus, forest, geranium
-
-
+
-
-
-
+
-
-
+
- the biggest peak on the olfactogram.
* - compounds detected by one person of sensory-panel
fruit, herbal, dill
sweet, tropic, ginger, herbal, geranium,
green
sweet, honey, floral, herbal, chocolate,
lilac
sweet, multivitamin, apple, cumarin
sweet, herbal, delicate and apple,
raspberry
sweet, honey, floral, rose
sweet, floral, rose, violet
sweet, anise, marzipan, cherry
sweet, raspberry-currant syrup, grape,
gummous
Fig. 4. Comparison of olfactograms and chromatograms of honey samples
297
298
Flavour compounds detected by sensory-panel (3 estimators) were registered in the
form of olfactograms by fingerspan method. 37 volatile flavour compounds were
identified after comparison of their retention times from olfactogram with chromatogram
(Fig. 4). Retention time differences (between GC-MS and GC-O) were determinated by
passing standard mixture through the chromatographic system. It was caused by fact that
olfactometer was coupled with chromatographic column using longer transfer line in
comparison with mass spectrometer interface, different flow rate mobile phase in
proportion to auxiliary gas and various conditions in both systems. Additionally, for the
purpose of confirmation of the identity of detected flavour compounds their sensory
panel aroma description (Tab. 3) was compared with literature data. Identified flavour
compounds might be useful for distinguishing different types of honeys (eg furfural for
buckwheat and linalol for honeydew).
Conclusions
The use of headspace stationary-phase microextraction (HS-SPME) and capillary
gas chromatography/mass spectrometry (GC-MS) allowed not only for finding the
dependence between the composition of the volatile fraction of agricultural distillates and
their sensory quality, but also allowed for the discovery of differences between the
composition of aromatic volatile compounds in agricultural distillates, originating from
different sources.
The elaborated procedure, based on HS-SPME-GC-MS and GC-O [30, 31], applied
for analysis of several popular Polish honeys (lime, acacia, buckwheat, rape and
honeydew) after determination the volatile fraction allowed to distinguish honeys
botanical origin. Differences in the volatile and flavour fraction composition of various
Polish honeys were observed, especially for buckwheat honeys, which contain
characteristic compounds (eg furfural). Created volatile profiles and unifloral type of
honey markers might be useful in adulteration detection and quality assessment of honeys
but in future greater amount of samples need to be analysed.
The obtained results have shown that instrumental analysis can complete or
substitute organoleptic analysis of spirits and honeys or pollen analysis.
Acknowledgements
This research was financially supported by the Department of Scientific Research
of the Polish Ministry of Scientific Research and Information Technology
(grant no. N312 056 31/3446).
References
[1]
[2]
[3]
[4]
Plutowska B., Wardencki W.: Aromagrams - Aromatic profiles in the appreciation of food quality. Food
Chem., 2007, 101, 845-872.
Majewska E. and Delmanowicz A.: Profile związków lotnych wybranych miodów pszczelich. Żywność.
Nauka. Technologia. Jakość, 2007, 5, 247-259.
Plutowska B. and Wardencki W.: Application of gas chrotomatography-olfactometry (GC-O) in
analysis and quality assessment of alcoholic beverages - A review. Food Chem., 2008, 107, 449-463
Cayot N.: Sensory quality of traditional food. Food Chem., 2007, 101, 154-162.
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
[28]
[29]
299
Aznar M., López R., Cacho J.F. and Ferreira V.: Identification and quantification of impact odorants of
aged red wines from Rioja. GC-Olfactometry, quantitative GC-MS, and odor evaluation of HPLC
Fractions. J. Agric. Food Chem., 2001, 49, 2924-2929.
Čačić F., Primorac L., Kenjerić D., Benedetti S. and Mandić M.L.: Application of electronic nose in
honey geographical origin characterization. JCEA, 2009, 10, 19-26.
Ampuero S., Bogdanov S. and Bosset J.-O.: Classification of unifloral honeys with an MS-based
electronic nose. Eur. Food Res. Technol., 2004, 218, 198-207.
Benedetti S., Mannino S., Sabatini A.G. and Marcazzan G.L.: Electronic nose and neural network use
for the classification of honey. Apidologie, 2004, 35, 1-6.
Ghidini S., Mercanti C., Dalcanale E., Pinalli R. and Bracchi P.G.: Italian honey authentication. Ann.
Fac. Medic. Vet. di Parma, 2008, 28, 113-120.
Falcão L.D., Revel G., Rosier J.P. and Bordignon-Luiz M.T.: Aroma impact components of Brazilian
Cabernet Sauvignon wines using detection frequency analysis (GC-olfactometry). Food Chem., 2008,
107, 497-505.
Lermusieau G., Bulens M. and Collin S.: Use of GC-Olfactometry to identify the hop aromatic
compounds in beer. J. Agric. Food Chem., 2001, 49, 3867-3874.
Berdagué J.L., Tournayre P. and Cambou S.: Novel multi-gas chromatography-olfactometry device and
software for the identification of odour-active compounds. J. Chromatogr. A, 2007, 1146, 85-92.
Pino J.A., Marbot R., Rosado A. and Vázquez C.: Volatile constituents of Malay rose apple [Syzygium
malaccense (L.) Merr. & Perry]. Flavour Frag. J., 2004, 19, 32-35.
Chung T.Y., Eiserich J.P. and Shibamoto T.: Volatile compounds isolated from edible Korean
Chamchwi (Aster scaber Thunb). J. Agric. Food Chem., 1999, 41, 1693-1697.
Rembold H., Wallner P., Nitz S., Kollmannsberger H. and Drawert F.: Volatile components of chickpea
(Cicer arietinum L.) seed. J. Agric. Food Chem., 1989, 37, 659-662.
Loon W.A.M., Linssen J.P.H., Legger A., Posthumus M.A. and Voragen A.G.J.: Identification and
olfactometry of French fries flavour extracted at mouth conditions. Food Chem. 2005, 90, 417-425.
Ledauphin J., Guichard H., Saint-Clair J.-F., Picoche B. and Barillier D.: Chemical and sensorial aroma
characterization of freshly distilled calvados. 2. Identification of volatile compounds and key odorants.
J. Agric. Food Chem., 2003, 51, 433-442.
Fan W. and Qian M.C.: Headspace solid phase microextraction and gas chromatography-olfactometry
dilution analysis of young and aged Chinese "Yanghe Daqu" liquors. J. Agric. Food Chem., 2005, 53,
7931-7938.
Isidorov V. and Jdanova M.: Volatile organic compounds from leaves litter. Chemosphere 2002, 48,
975-979.
Ansorena D., Gimeno O., Astiasaran I. and Bello J.: Analysis of volatile compounds by GC-MS of a dry
fermented sausage: chorizo de Pamplona. Food Res. Int., 2001, 34, 67-75.
Kubec R., Drhová V. and Velísek J.: Thermal degradation of S-methylcysteine and its
sulfoxide-important flavor precursors of Brassica and Allium vegetables. J. Agric. Food Chem. 1998,
46, 4334-4340.
Tellez M.R., Schrader K.K. and Kobaisy M.: Volatile components of the cyanobacterium oscillatoria
perornata (Skuja). J. Agric. Food Chem., 2001, 49, 5989-5992.
Javidnia K., Miri R., Safavi F., Azarpira A. and Shafiee A.: Composition of the essential oil of Nepeta
persica Boiss from Iran. Flavour Frag. J., 2002, 17, 20-22.
Larsen T.O. and Frisvad J.C.: Characterization of volatile metabolites from 47 Penicillium taxa. Mycol.
Res. 1995, 99, 1153-1166.
Cullere L., Escudero A., Cacho J. and Ferreira V.: Gas chromatography-olfactometry and chemical
quantitative study of the aroma of six premium quality spanish aged Red wines. J. Agric. Food Chem.,
2004, 52, 1653-1660.
Guth H.: Quantitation and sensory studies of character impact odorants of different white wine
varieties. J. Agric. Food Chem. 1997, 45, 3027-3032.
Benn S.M. and Peppard T.L.: Characterization of tequila flavor by instrumental and sensory analysis.
J. Agric. Food Chem., 1996, 44, 557-566.
Darriet P., Pons M., Lamy S. and Dubourdieu D.: Identification and quantification of geosmin, an
earthy odorant contaminating wines. J. Agric. Food Chem. 2000, 48, 4835-4838.
Odeh I., Abu-Lafi S., Dewik H., Al-Najjar I. and Imam A.: A variety of volatile compounds as markers
in Palestinian honey from Thymus capitatus, Thymelaea hirsuta, and Tolpis virgata. Food Chem., 2007,
101, 1393-1397.
300
[30] Wolski T., Tambor K., Rybak-Chmielewska H. and Kędzia B.: Identification of honey volatile
components by solid phase microextraction (SPME) and gas chromatography/ mass spectrometry
(GC/MS). J. Apicult. Sci., 2006, 50, 115-125.
[31] Soria A.C., Sanz J. and Martinez-Castro I.: SPME followed by GC-MS: a powerful technique for
qualitative analysis of honey volatiles. Eur. Food Res. Technol., 2009, 228, 579-590.
ZASTOSOWANIE CHROMATOGRAFII GAZOWEJ,
SPEKTROMETRII MAS I OLFAKTOMETRII
W OCENIE JAKOŚCI WYBRANYCH PRODUKTÓW SPOŻYWCZYCH
Katedra Chemii Analitycznej, Wydział Chemiczny, Politechnika Gdańska
Abstrakt: Stosując mikroekstrakcję do fazy stacjonarnej z fazy nadpowierzchniowej jako metodę
przygotowania próbek i chromatografię gazową (GC) ze spektrometrią mas (MS) i olfaktometrią (O) jako
metodę oznaczeń końcowych, oznaczono lotne związki w spirytusach i miodach. Identyfikację
przeprowadzono przez porównanie widm masowych z widmami z biblioteki NIST. Dodatkowo, wykrywane
przez panel oceniający związki zapachowe rejestrowano w formie olfaktogramów, stosując metodę „odcisku
palca”. Analiza surowych spirytusów wykazała obecność ponad 200 związków, z których większość została
zidentyfikowana (estry, wyższe alkohole, aldehydy, acetale, a także furany, związki siarki, terpenoidy
i pochodne benzenu). Stwierdzono, że ponad 50 związków z tej grupy to związki odpowiedzialne za
pogorszenie jakości destylatów. W rezultacie przeprowadzonej analizy miodów zidentyfikowano 163 lotne
i średniolotne związki (alifatyczne i aromatyczne kwasy, aldehydy, ketony, aldehydy i fenole, terpenoidy,
pochodne furanu i piranu). Spośród tych związków wskazano markery każdego typu miodu. Lista markerów
pozwala rozróżniać i kontrolować jakość (np. stwierdzić zafałszowanie) polskich miodów. Zastosowanie
dodatkowo metody GC-MS połączonej z olfaktometrią pozwoliło stworzyć profile związków zapachowych
badanych miodów. Zastosowane metody charakteryzują się duża czułością i powtarzalnością, a ponadto są
względnie szybkie.
Słowa kluczowe: lotne związki zapachowe, spirytusy rolnicze, miody, mikroekstrakcja do fazy stacjonarnej,
chromatografia gazowa, spektrometria mas, olfaktometria
Vol. 16, No. 3
2009
Magnuss VIRCAVS*
CHEMICAL COMPOSITION AND ASSESSMENT
OF DRINKING WATER QUALITY: LATVIA CASE STUDY
SKŁAD CHEMICZNY I OCENA JAKOŚCI WODY PITNEJ.
ŁOTWA - STUDIUM PRZYPADKU
Abstract: Assessment of drinking water quality in seven largest Latvia drinking water supply systems (Riga,
Daugavpils, Liepaja, Ventspils, Jelgava, Jurmala, and Rezekne) in 2008 using mathematical statistical
processing of chemical composition data and calculation of drinking water quality indexes are carried out.
Daugavpils, Liepaja, Ventspils, and Rezekne drinking water supply systems are assessed as excellent, Riga
and Jurmala - good, but Jelgava - fair quality of drinking water. In Jelgava drinking water sulphate
concentration exceed the accepted maximum permissible value (MPV) for 97 mg/dm3 and in Jurmala - for
26 mg/dm3. Besides, high values of total iron (1.15 ±0.54 mg/dm3) and turbidity (14.2 ±7.2 nephelometric
turbidity units) were obtained also in Jelgava drinking water. Relative high concentration of aluminum in
Liepaja drinking water (0.2 mg/dm3) takes place that achieves the MPV (0.2 mg/dm3). In all analyzed drinking
water the concentrations of Hg, Cd, Pb, Cu, Ni, Cr (total), BrO3- and trihalomethanes (total) were observed in
the level of their determination or less than it or concentration changes were observed only in some cases that
are significantly less than their MPV. In general drinking water quality of the largest Latvia drinking water
supply systems is assessed as agreeable to the existed legal norms.
Keywords: drinking water quality, chemical composition, mathematical statistics, and drinking water quality
indexes, Latvia
Introduction
Provision of a qualitative drinking water is an important precondition for
improvement of the life quality. Drinking water quality directly affects human health.
The impacts reflect the level of contamination of whole drinking water supply system
(raw water, treatment facilities and distribution network to consumers). The primary
goals of environmental especially drinking water management are to provide safe
drinking water supply in international and national scale. The international organizations,
eg World Health Organization (WHO) have major functions to propose regulations,
guidelines, and recommendations in order to realize human right to have access to an
*
Faculty of Geography & Earth Sciences, University of Latvia, 10 Alberta St., Rīga, LV-1010, Latvia
302
Magnuss Vircavs
adequate of safe drinking water independently of their stage of development and their
social and economic conditions [1].
Latvia has rich water resources, especially freshwater, which well exceeds current
and planned consumption. In general chemical structure of raw water resources ensure to
meet adequacy requirements of drinking water quality determined by Council Directive
98/83/EC of 3 November 1998 on the quality of water intended for human consumption
and Republic of Latvia Cabinet Regulation No. 235 “Mandatory harmlessness and
quality requirements for drinking water, and the procedures for monitoring and control
thereof” (adopted 29 April 2003).
Management of drinking water quality is a matter of great importance in Latvia.
Implementation of the State Investment Program 800+, drinking water regular and audit
monitoring as well as other environmental projects are integral part of public health and
environmental protection.
The present study is devoted to assessment of drinking water quality in seven largest
Latvia drinking water supply systems in 2008 using mathematical statistical processing of
chemical composition data.
Quality assessment of Latvia drinking water is carried out using chemical
composition data of drinking water obtained from the Public Health Agency of the
Ministry of Health. Drinking water was analyzed in 2008 in seven largest Latvia drinking
water systems - Riga, Daugavpils, Liepaja, Ventspils, Jelgava, Jurmala, and Rezekne
(Fig. 1).
Fig. 1. Latvia administrative map. The largest drinking water systems - Riga, Daugavpils, Liepaja,
Ventspils, Jelgava, Jurmala, and Rezekne [2]
Drinking water was sampled from the site of consumers and analyses were carried
out considering the requirements (testing methods, sampling frequency, the necessary
Chemical composition and assessment of drinking water quality: Latvia case study
303
precision and accuracy, maximum permissible values (MPV) of the variables) in
Republic of Latvia Cabinet Regulations No. 235 “Mandatory harmlessness and quality
requirements for drinking water, and the procedures for monitoring and control thereof”
(adopted 29 April 2003) and in Cabinet Regulations No. 118 adopted on March 12, 2002
“Regulations regarding the Quality of Surface Waters and Groundwaters” (with
amendments). Drinking water quality was evaluated by the following variables: color,
turbidity, pH, conductivity, aluminum, iron (total), fluorides, sulphates, ammonium,
nitrates(V), nitrates(III), mercury, cadmium, lead, copper, nickel, chromium, bromates,
trihalomethanes (total).
Data processing of drinking water chemical composition includes mathematical
statistical calculations. The Q-test was applied for suitability estimation of drinking water
data set. The mean and the confidence interval of chemical composition variables of
drinking water was expressed using Chebyshev’s inequality (confidence level α = 0.06):
0 – 4s/ n ≤ µ ≤ 0 + 4s/ n , where µ - mathematical expectation, 0 - mean, and
s - standard deviation, and 4s/ n - standard error of mean [3]. Rezekne drinking water
supply system was characterized only by two measurements of the variables. Availability
of the data for further processing was evaluated using also Chebyshev’s inequality:
|x1 – x2| < 4s (where x1 and x2 - results of measurements). It was used for estimation of
Al, Fe, F–, pH, turbidity, and conductivity values. Assessment of differences between
sample means was carried out using Bartlett’s test criterion.
Drinking water quality index (DWQI) was calculated using formulas set in Water
Quality Index 1.0 User Manual [4].
WHO, EU and Latvia drinking water standards
Drinking water quality assessment is based on the determination of legal selected
and accepted set of water quality variables of concern and their comparison
with regulatory standards. Drinking water quality characterizes the chemical,
physical-chemical and microbiological variables.
WHO produces international norms on water quality and human health in the form
of guidelines that are used as the basis for regulation and standard setting in developing
and developed countries worldwide. The Guidelines provide a range of supporting
information, including microbial, chemical, radiological aspects and acceptability
aspects. In 2006 WHO published Guidelines for drinking water quality [1] that replace
the previous Guidelines for drinking water quality of 1993. Comparison of WHO
drinking water standards of 1993 and of 2006 shows that many standards are less strict
now, e.g. for antimony, boron, carbon tetrachloride. In return some other standards of the
variables are much stricter in the recent WHO drinking water standards, like uranium and
DDT. Besides, there are no guidelines any more for some variables such as chloride,
sodium, sulphate, zinc and some others.
EU water policy is primarily codified in the Council Directive 91/271/EEC of 21
May 1991 concerning urban wastewater treatment, the Drinking Water Directive
98/83/EC of 3 November 1998 on the quality of water intended for human consumption,
and the Directive 2000/60/EC of the European Parliament and of the Council of 23
October 2000 establishing a framework for Community action in the field of water
304
Magnuss Vircavs
policy. The requirements of the directives have incorporated in national water policy of
the EU member states.
The Drinking Water Directive 98/83/EC ensures that water intended for human
consumption is safe. The Directive 98/83/EC aims both protection of human health and
also the environment. Precautionary principle is reflected in the Directive 98/83/EC
setting contaminant levels. In general the EU standards are in line with WHO guidelines
for drinking water quality of 2006. However there are differences between WHO and EU
standards. For example, cadmium health based guideline by the WHO is 0.003 mg/dm3
but EU standards qualify cadmium concentration 0.005 mg/dm3. The WHO guidelines of
2006 do not set health based guideline for iron. However the WHO guidelines of 1993
defined desirable iron concentration 0.3 mg/dm3 that is higher than EU standard for Fe
(0.2 mg/dm3).
Latvia drinking water standards are set in Republic of Latvia Cabinet Regulations
No 235 “Mandatory harmlessness and quality requirements for drinking water, and the
procedures for monitoring and control thereof” that contain legal norms arising from the
Directive 98/83/EC. Latvia has transitional arrangements for providing of safe drinking
water quality up to December 2015 in order to introduce the goals of the Directive
98/83/EC.
Drinking water quality indexes
A major objective of drinking water quality assessment is to determine whether or
not the drinking water quality meets previously defined objectives for designated uses, to
describe drinking water quality at regional, national or international scales, and also to
investigate trends in time as well as to provide environmental including drinking water
managers, technological staff of drinking water supply, scientists and public with
a multitude of data and detail information on drinking water quality.
Water quality data is usually summarized in technical reports that are very valuable
to individuals who understand the technical content, however, this information is not
always useful to non-technical individuals. Therefore a water as well as drinking water
indexes are processed. The objective of the DWQI is to turn drinking water quality data
(chemical, physical-chemical and microbiological) into understandable, easily accessible,
and useable by the public information [5]. The development of DWQI gives a tool for
simplifying the reporting of water quality data [4, 5]. The index essentially is
a mathematical instrument used to transform large quantities of water quality data into
a single number that represents water quality level. A number of indices have been
developed and their differences include the mathematical way describing water including
drinking water quality data, eg exponential function, the Pearson type 3-distribution
function and others [6]. Since 1965 a great deal of consideration has been given to the
development of water quality index methods [6, 7].
The DWQI is to consumers enlightened information on drinking water quality. The
DWQI is a unit less number ranging from 1 to 100. A value of 100 means the best
possible index (excellent quality) and a value of 0 - the worst possible index (poor
quality). The DWQI expresses overall water quality. Besides, the developed
mathematical models of the DWQI characterize an attendance and concentration of
individual as well as selected chemical substances in drinking water. The DWQI
305
developed by the Canadian Council of Environment Ministers [4] is widely used. The
DWQI includes three measures of variance from the selected drinking water quality
objectives - scope (F1), frequency (F2), and amplitude (F3) [4]. The scope represents the
extent of water quality legal norm non-compliance over the time period of interest. The
scope is expressed:
F1 = [(Number of failed variables) / (Total number of variables)] × 100 (%)
(1)
The frequency characterizes percentage of individual tests that do not meet
objectives:
F2 = [(Number of failed tests) / (Total number of tests)] × 100 (%)
(2)
The amplitude represents the amount by which failed tests do not meet their
objectives:
F3 = nse/ (0.01× nse + 0.01)
(3)
where nse indicates the normalized sum of excursions that is the collective amount by
which individual tests are out of compliance.
The DWQI is calculated as:
DWQI = 100 – [(√F12 + F22 + F32)/1,732]
(4)
Characteristic of Latvia drinking water supply and quality control
Latvia has rich water resources, especially freshwater, which well exceeds current
and planned consumption. Water resources allow providing high quality drinking water
for all population - 70% is composed from artesian and 30% from surface water sources
(rivers and lakes). Total amount of surface waters comprises 13,300 m3 per capita but in
EU it comprises at an average 7,250 m3 per capita [8]. In most water supply systems
hydrogen-carbonate calcium water with mineralization 0.3÷0.4 g/dm3 is used. Chemical
structure of rock and infiltration water is caused by calcium hydrogencarbonate water.
Mostly artesian waters are used for the centralized water supply in Latvia drinking
water supply systems. They are better protected than ground water table. Drinking water
sources for the capital of Latvia Riga comprise a mixture of surface, natural groundwater,
and artificially recharged groundwater from Lake Mazais Baltezers that is the main
source for artificial recharge plant supplying up to 25% of Riga drinking water [9].
Reservoir of Riga hydro-power plant on the Daugava River is used as a surface water
source. The Daugava Waterworks is the largest surface water treatment plant in Latvia
that purifies more than 100000 m3 per day using alum as a coagulant [10]. However,
quality of water taken from the reservoir of Riga hydro-power plant depends on
transboundary pollution that enters into the Daugava River from Russia and Belarus. In
the period from 1990 to 1997 three large accidents happened in the river Daugava basin.
In November 1990 during filling a railroad tank in a chemical plant “Polimir”,
Novopolock (Belarus) spill of acetone cyanohydrin (ACH - operates on respiratory
centers) occurred. Significant amount of ACH leaked into the Daugava River. Due to the
pollution mass fish deaths were observed in the river. Therefore during one week water
supply from the Daugava River was interrupted in Riga. The second accident involved
sanitation leakage from Belarus in the middle of 1990s. The last accident, disruption of
oil pipe line Unecha - Ventspils (enterprise „Zapad-Transnefteprodukt”, Russia), caused
306
Magnuss Vircavs
the Daugava River ecosystem contamination with diesel fuel that happened 23 March
2007. Diesel fuel of 4,171 Mg entered into the territory of Latvia, but ~90% was
collected from the Daugava River waters. The noted accidents can originate and affect
Riga as Republic of Latvia capital drinking water quality [11].
Drinking water quality control and assessment is developed in two stages. The first
includes drinking water analysis in accordance with the requirements of the Regulations
No. 235. The second stage comprises comparison of the obtained data with the MPV of
physical-chemical, chemical, and microbiological variables, determination of the scope
(F1) and frequency (F2).
The Public Health Agency is liable for monitoring of drinking water quality against
the standards set in the Regulations No. 235. The Public Health Agency develops
a drinking water monitoring program that includes regular and audit monitoring as well
as the Agency carries out monitoring data assessment. In the period from 2000 to 2008
Latvia drinking water quality assessment is summarized in Figure 2. The data show the
tendency to decrease of percentage of chemical variable unconformity of audit
monitoring but regular monitoring data testify fluctuations around 36÷40%.
Unconformity of microbiological variables during the tested period fluctuates in the
range 3÷10% and likely it will decrease. The high concentrations of iron, manganese,
ammonium, sulphates, and values of color, turbidity and some others comprise
unconformity of drinking water quality in respect to chemical composition [12].
100
Unconformity [%]
80
60
40
20
0
1998
2000
1
2002
2
2004
Year
3
2006
2008
2010
4
Fig. 2. Unconformity of chemical and microbiological variables of Latvia drinking water quality:
1 and 2 - chemical and microbiological variables of audit monitoring; 3 and 4 - chemical and
microbiological variables of regular monitoring
Harmlessness and quality requirements of the Directive 98/83/EC and the
Regulations No. 235 are not applied to drinking water obtained from separate places
(individual households) of production or supply which are utilized by less than 50
persons and the amount of the supply of which does not exceed 10 m3 per 24 h. Thereby
307
in rural areas about 10% or 200,000 inhabitants of Latvia are using drinking water from
wells that is not comply with the control of state health and sanitary institutions. The
centralized drinking water supply, for example in the studied seven largest Latvia
drinking water supply systems is provided for 1,011,350 residents (in 2008 total Latvia
population comprise 2,270,894).
Statistical description of drinking water chemical composition
The analyzed drinking water data of seven largest Latvia drinking water supply
systems are conditionally divided into two groups. The first group involves the variables
whose values do not change. They are the concentrations of Hg, Cd, Pb, Cu, Ni, Cr
(total), BrO3− and trihalomethanes (total). These variables were observed in the level of
their determination or less than it or concentration changes were observed only in some
cases. The lowest observed concentrations are the following (in µg/dm3): Hg - 0.1,
Cd - 0.5, Pb - 1.0, Cu - 0.2, Ni - 2.0, Cr (total) - 1.0, BrO3− - 1.0, and trihalomethanes
(total) - 10.0. Besides, the exceptions comprised total Cr concentration in Daugavpils
drinking water - 20.0 µg/dm3 and Ni concentration in Jelgava drinking water - 5.4 µg/dm3
(1 measurement). Total concentrations of trihalomethanes of Riga drinking water varied
in the wide range of 0.1÷50.1 µg/dm3 (mean and standard error of mean
23.8 ±0.35 µg/dm3). The same statistics for total concentrations of trihalomethanes of
Liepaja drinking water are the following: range of 0.10÷1.14 µg/dm3, mean and standard
error of mean - 0.54 ±0.21 µg/dm3. All noted concentrations are less than their MPV.
Drinking water color modified in the range of 5÷10 units of Pt/Co scale with the
exception of 20 units of Pt/Co scale in Daugavpils and Jurmala drinking water
(1 measurement). The second group includes the variables whose value changes were
observed - turbidity, pH, and conductivity, concentrations of Al, Fe (total), F–, SO 24− ,
NH +4 , NO3− , and NO −2 . The obtained data of processing are summarized in Table 1.
Data set distribution character was estimated only for Riga drinking water variables
(sample size n = 18) and its inadequacy to normal distribution was obtained. Therefore
Chebyshev’s inequality was applied to calculate confidence intervals of variable means
because Chebyshev’s theorem could be used to random variables of any distribution.
Comparison of variable mean and median shows that these statistics are not equal
for all variables. Median is a statistic that is sensitive to data set symmetric or
asymmetric distribution. Data symmetric distribution is observed if the mean and median
are equal but in the opposite case - asymmetric distribution. Considering the diversity of
sample sizes from n = 2 to n = 18 evaluation of data distribution character was not
carried out. Comparison of differences between sample means at confidence level
α = 0.05 using Bartlett’s test criterion testifies on the following assurance.
In all analyzed drinking water systems nitrate(III) and fluoride concentrations do not
significantly differ. Mean concentration of aluminum in Liepaja drinking water system
(0.2 mg/dm3) significantly differs from its concentration in other drinking water systems
that have statistically equal value 0.02 mg/dm3. Concentration of aluminum in Liepaja
drinking water is equal with MPV (0.2 mg/dm3).
308
Magnuss Vircavs
Table 1
Characteristics of chemical composition in the largest Latvia drinking water supply systems (2008)
Statistic
Riga1
678,0002
Daugavpils
82,467
0 ±SEM4
Me5
Range
0.08 ±0.04
0.08
0.02÷0.2
0.05 ±0.05
0.02
0.01÷0.10
Liepaja
Ventspils
79,300
39,363
Al, MPV3 - 0.2 mg/dm3
0.26
0.026
Jelgava
59,670
Jurmala
42,550
Rezekne
30,000
0.026
0.026
0.04 ±0.02
NH +4 , MPV - 0.5 mg/dm3
0 ±SEM
Me
Range
0.04 ±0.02
0.04
0.006÷0.08
0 ±SEM
Me
Range
0.12 ±0.07
0.13
0.003÷0.66
0 ±SEM
Me
Range
0.13 ±0.08
0.09
0.09÷0.26
0.10 ±0.04
0.04 ±0.04
0.10
0.046
0.03
0.06÷0.12
0.003÷0.01
Fe (total), MPV - 0.2 mg/dm3
0.13 ±0.12
0.04 ±0.02 0.08 ±0.08
0.10
0.002
0.07
0.10÷0.14
0.001÷0.01 0.04÷0.12
F–, MPV - 1.5 mg/dm3
0.11 ±0.02
0.45 ±0.11
0.10
0.48
0.056
0.10÷0.16
0.35÷0.51
0.11 ±0.11 0.04 ±0.02
0.12
0.03
0.05÷0.17 0.03÷0.06
0.036
1.15 ±0.54 0.06 ±0.04
1.13
0.06
0.05 ±0.03
0.21÷2.15 0.05÷0.10
0.07 ±0.07 0.21 ±0.26
0.05
0.18
0.31 ±0.15
0.05÷0.13 0.05÷0.50
NO 3− , MPV - 50 mg/dm3
0 ±SEM
Me
Range
1.9 ±1.6
1.00
0.24÷5.12
0.86 ±0.48
0.80
0.41÷1,20
0.0136
0.9 ±0.9 0.24 ±0.12
0.7
0.21
0.003÷2.0 0.20÷0.32
0.56
1.16
0.0086
0.046
276 ±129
267
192÷394
106
NO 3− , MPV - 0.5 mg/dm3
0 ±SEM
Me
Range
0.008 ±0.008
0.002
0.003÷0.016
0.05 ±0.04
0.04
0.04÷0.08
0.0036
0.36
0.016
SO 24− , MPV - 250 mg/dm3
0 ±SEM
Me
Range
43.0 ±14.0
27.4
11÷81.1
0 ±SEM
Me
Range
7.58 ±0.40
7.83
6.91÷8.01
0 ±SEM
Me
Range
0.38 ±0.04
0.34
0.11÷0.65
210 ±28
347 ±164
215
2.16
316
185÷227
288÷468
pH, maximum permissible interval 6.5÷9.5
7.88 ±0.16
7.74 ±0.01 7.62 ±0.32
7.90
No data
7.72
7.59
7.77÷8.00
7.73÷7.76 7.48÷7.82
Turbidity
14.2 ±7.4
0.31 ±0.11
0.20
0.586
16
11.3
0.11÷0.90
1.83÷32.4
Conductivity, MPV - 2500 µS/cm
334 ±220
874 ±8
377 ±8
944 ±172
263
871
377
911
242÷591
857÷899
375÷380 884÷1070
106
7.16 ±1.00
7.38
7.22 ±0.03
6.00÷7.45
2.9 ±0.04
0.9
0.9÷12.9
0.6 ±0.1
358 ±76
1189 ±315
0 ±SEM
335
1133
520 ±10
Me
293÷543
972÷1478
Range
1
Drinking water supply system
2
Number of residants that use drinking water
3
Maximum permissible values (Republic of Latvia Cabinet Regulations No 235 “Mandatory harmlessness
and quality requirements for drinking water, and the procedures for monitoring and control thereof” (adopted
29 April 2003))
4
0 ± SEM: mean and standard error of mean 0 ± 4s/√n, where 0 - mean, s - standard deviation and
n - sample size
5
Me - median
6
All results in the series are equal
309
Total iron concentration (1.15 ±0.54 mg/dm3) in Jelgava drinking water system
significantly differs from total iron concentration of other systems but it does not exceed
the MPV. High iron concentration is an important problem of drinking water quality in
Latvia that is caused by high content of iron in ground water tables. Therefore drinking
water de-ironing is included in Latvia drinking water processing.
In Riga drinking water nitrate(V) concentration has a wide dispersion that is
specified by high standard deviation (±1.6 mg/dm3). Mean concentration of nitrate(V)
(1.9 mg/dm3) is significantly higher than in other drinking water systems that are in the
range from 0.013 to 1.1 mg/dm3.
Sulphate concentrations in Jelgava (347 ±41 mg/dm3) and Jurmala
(276 ±32 mg/dm3) drinking water systems are significantly higher than in drinking water
of Riga, Daugavpils, Liepaja, Ventspils, and Rezekne. High concentrations of sulphate in
drinking water have natural origin owing leakage from gypsum formations. Comparison
of sulphate concentrations with the MPV shows that in Jelgava drinking water average
linear deviation is 97 mg/dm3 and in Jurmala - 26 mg/dm3.
In all drinking water systems conductivity mean values have a great dispersion with
significantly high values of 1189 ±315 and 944 ±172 µS/cm in drinking water of Jelgava
and Jurmala. It could be explained by high concentrations of sulphates.
Signinficantly high value of turbidity (14.2 ±7.4) was observed in Jelgava drinking
water. The Regulations No. 235 testifies turbidity values as acceptable to consumers and
no substantial changes. In the case of surface water treatment, it should be striven to
reach that turbidity caused by treatment plants does not exceed 1.0 nephelometric
turbidity units.
Mean of drinking water pH falls in the range from 7.16 (Jurmala) to 7.88
(Daugavpils). pH of Riga and Jurmala drinking water significantly differs from pH of
Daugavpils, Ventspils, Rezekne, and Jelgava drinking water owing their data great
dispersion. Mean values pH stand in the pH range 6.5÷9.5 satisfied in the Regulations
No. 235.
Drinking water quality index
The calculated DWQI of seven largest drinking water supply systems summarized in
Table 2 show satisfied drinking water quality in the range from fair to excellent quality.
The DWQI have additional information that was obtained using mathematical statistical
assessment. The exceeded concentrations of iron and sulphate and values of turbidity
deteriorate drinking water quality.
The removal of iron and together with it some other substances is the most important
step in artesian water treatment facilities in order to meet MPV of drinking water
chemical composition. In regard to consumers 82,467 residents in Daugavpils, 79,300 in
Liepaja, 39,363 in Ventspils, and 30,000 in Rezekne use drinking water of excellent
quality, 678,000 in Riga and 42,500 in Jurmala - of good, and 59,670 in Jelgava - of fair
quality drinking water.
310
Magnuss Vircavs
Table 2
Drinking water quality indexes and their characteristics of the largest Latvia drinking water supply systems
Drinking
water supply
system
Daugavpils
2
97
Ventspils
97
Liepaja
Rezekne
95-100
95-100
Riga
91
Jurmala
81
Jelgava
1
DWQI1
69
Water quality categories [4]
Excellent: water quality is protected with
a virtual absence of threat or impairment;
conditions very close to natural or pristine levels.
Good: water quality is protected with only
a minor degree of threat or impairment;
conditions rarely depart from natural or desirable
levels.
Fair: water quality is usually protected but
occasionally threatened or impaired; conditions
sometimes depart from natural or desirable
levels.
Failed tested variables
1 test - Fe (total)
1 test - NO −2
All tests are below the
MPV2
3 tests - Fe (total), 1 test turbidity and pH,
respectively
3 tests - sulphates,1 test
turbidity and pH,
respectively
4 tests - sulphates, Fe
(total), and turbidity,
respectively
DWQI - drinking water quality index
MPV - maximum permissible value
Conclusions
The carried out quality assessment of seven largest Latvia drinking water supply
systems (Riga, Daugavpils, Liepaja, Ventspils, Jelgava, Jurmala, and Rezekne) in general
shows high drinking water quality. Chemical variable data analyses were carried out
using mathematical statistics and calculating drinking water quality indexes. Among the
studied drinking water supply systems Daugavpils, Liepaja, Ventspils, and Rezekne
drinking water supply systems are assessed as excellent, Riga and Jurmala - good but
Jelgava - fair quality of drinking water. Jelgava drinking water quality is significantly
detoriated by high concentrations of sulphates and total iron, and values of turbidity. The
concentration of aluminum in drinking water (0.2 mg/dm3) is achieved the maximum
permissible value in spite of excellent drinking water quality in Liepaja. The
concentrations of Hg, Cd, Pb, Cu, Ni, Cr (total), BrO3− and trihalomethanes (total) are in
the level of their determination or less than it or concentration changes were observed
only in some cases that are significantly less than their MPV in all analyzed drinking
water systems.
Acknowledgements
The author thanks the concerned authorities the Public Health Agency of the
Ministry of Health for providing facilities to carry out this study.
References
[1]
[2]
World Health Organisation: Guidelines for Drinking-water Quality. 3rd edition, incorporating the 1st
and 2nd addenda, Vol. 1, Recommendations, Geneva 2008.
Latvia (Small Map) 2008, Map Collection, Latvia Maps, Perry-Castañeda Library
(http://www.lib.utexas.edu/maps/latvia.html).
311
[3]
[4]
Freund J.E.: Introduction to probability. Dickenson Publishing Company, Encino - Belmont, Calif. 1973.
Canadian water quality guidelines for the protection of aquatic life: CCME Water Quality Index 1.0
User’s Manual. Canadian Environmental Quality Guidelines, Canadian Council of Ministers of the
Environment 2001.
[5] Khan A.A., Paterson R. and Khan H.: Modification and Application of the Canadian Council of
Ministers of the Environment Water Quality Index (CCME WQI) for the Communication of Drinking
Water Quality Data in Newfoundland and Labrador. Water Qual. Res. J. Canada, 2004, 39(3), 285-293.
[6] Nasirian M.: A New Water Quality Index for Environmental Contamination Contributed by Mineral
Processing: A Case Study of Amang (Tin Tailing) Processing Activity. J. Appl. Sci., 2007, 7(20),
2977-2987.
[7] Boyacioglu H.: Development of a water quality index based on a European classification scheme.
Water SA, 2007, 33(1), 101- 106.
[8] Juhna T.: Atdzelžošanas principi un to pielietojums dzeramā ūdens sagatavošanai, Baltic Environment
Forum Latvia. (Principles of de-ironing and their use for drinking water processing; in Latvian) 2007.
[9] Springe G. and Juhna T.: Water Supply and Sanitation in Riga: Development, Present, and Future,
401-410. [In:] Environmental History of Water: Global Views on Community Water Supply and
Sanitation. Editors: P.S Juuti, T.S. Katko and H.S. Vuorinen, 2007, 640 p.
[10] Juhna T. and Klavins M.: Water-Quality Changes in Latvia and Riga 1980-2000: Possibilities and
Problems. Ambio, 2001, 30(4-5), 306-314.
[11] Vircavs M.: Development of Environmental Management System in Latvia and Threats of
Environmental Terrorism. Ecol. Chem. Eng. S, 2009, 16(1), 51-61.
[12] Review of drinking water quality, Public Health Agency of Republic of Latvia,
(http://www.vm.gov.lv/index.php?setlang=en)
SKŁAD CHEMICZNY I OCENA JAKOŚCI WODY PITNEJ.
ŁOTWA - STUDIUM PRZYPADKU
Abstrakt: W 2008 r. za pomocą metody matematyczno-statystycznej przetwarzania danych, dotyczących
składu chemicznego i obliczenia wskaźników jakości wody pitnej, przeprowadzono ocenę jakości wody pitnej
w siedmiu największych systemach wody pitnej Łotwy. Systemy wody pitnej Daugavpils, Liepaja, Ventspils
i Rezekny zostały ocenione jako bardzo dobre, Rygi i Jurmaly - jako dobre, natomiast Jelgavy - jako o dość
dobrej jakości wody pitnej. W wodzie pitnej Jelgavy stężenie siarczanów przekraczało maksymalne wartości
dopuszczalne (MPV) - 97 mg/dm3 a w Jurmala - 26 mg/dm3. W wodzie pitnej Jelgavy stwierdzono też duże
całkowite stężenie żelaza (1,15 ±0,54 mg/dm3) i również poziom mętności (14,2 ±7,2 (NTU)). Oznaczono
stosunkowo duże stężenie glinu (0,2 mg/dm3) w wodzie pitnej Liepaji, bliskie wartości MPV. We wszystkich
analizowanych wodach pitnych stężenie Hg, Cd, Pb, Cu, Ni, Cr (stężenie całkowite), BrO3− i trihalometanów
(stężenie całkowite) było na granicy oznaczalności albo poniżej lub obserwowano jedynie zmiany
w niektórych przypadkach (stężenie było znacznie poniżej dopuszczalnej wartości maksymalnej - MPV).
Ogólnie jakość wody pitnej z największych systemów wody pitnej Łotwy oceniono jako zgodną z obecnymi
normami prawnymi.
Słowa kluczowe: jakość wody pitnej, skład chemiczny, statystyki matematyczne, indeksy jakości wody pitnej,
Łotwa
Vol. 16, No. 3
2009
Stephan FRANKE*, Agnieszka SAGAJDAKOW**1, Lidia WOLSKA**,***
and Jacek NAMIEŚNIK**
INTEGRATED APPROACH - THE EFFECTIVE TOOL
FOR POLLUTION LEVEL CONTROL OF SEDIMENTS
FROM LAKE TURAWSKIE
KOMPLEKSOWA OCENA STOPNIA ZANIECZYSZCZENIA
OSADÓW DENNYCH JEZIORA TURAWSKIEGO
Abstract: Lake Turawskie, an artificial reservoir on the Mała Panew River, was selected for a preliminary
project financed by the Province Environment Protection Fund in Opole (Poland). The aim of this project was
to assess the ecological state of this lake, and testing aqueous extracts from bottom sediments for toxic effects
was one of the approaches. The toxicity of aqueous extracts of sediments was assessed applying the
measurements of bioluminescence inhibition of Vibrio fischeri bacteria. In addition, analyses of organic
compounds in sediment extracts obtained by aqueous and subsequent dichloromethane extraction were
performed. The chromatograms from coupled gas chromatography - mass spectrometry (GC/MS) indicated
a very complex composition of the examined dichloromethane extracts. The GC/MS non target screening
analyses were conducted on a set of selected samples as an attempt to identify chemical substances responsible
for the observed toxicity effects. However, the differences in sediment toxicity were not reflected in the results
of the GC/MS analyses and it was not possible to correlate sediment toxicity with specific organic compounds.
Keywords: gas chromatography-mass spectrometry, organic compounds, lake sediments, Microtox test,
Vibrio fischeri
Lake sediments contain thousands of substances of natural and anthropogenic origin.
Taking into account that an unknown number of them are toxic, the presence of some
compounds may have a negative influence on an aquatic ecosystem. Therefore, it is very
important to obtain reliable information about the toxicity of the lake’s sediments.
*
Institute of Organic Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, D-20146 Hamburg,
Germany
**
Department of Analytical Chemistry, Chemical Faculty, Gdańsk University of Technology,
ul. Narutowicza 11/12, 80-952 Gdańsk, Poland
***
Medical University of Gdansk, Inter-Faculty Institute of Maritime and Tropical Medicine, Department of
Environmental Toxicology, ul. Powstania Styczniowego 9b, 81-519 Gdynia, Poland
1
314
Stephan Franke, Agnieszka Sagajdakow, Lidia Wolska and Jacek Namieśnik
Chemical analysis provides only a part of the knowledge necessary to evaluate and
assess the toxic potential of compounds for wildlife and humans. This is due to the
different bioavailability of forms in which pollutants exist in the environment and their
different biological activities. Furthermore, complex interactions between different
environmental chemicals are not completely understood and considered [1].
A complementary approach, taking into account the above-mentioned facts, can be the
application of biotests. Bioassays provide data about the effect, without pinpointing the
substances and the potential source. Therefore, a procedure is necessary for providing
toxicity data, as well as identification of the compounds causing the effects [2].
An integrated approach based on a parallel application of bioassays and chemical
analysis is the most promising tool for the assessment of environmental pollution [2-5].
Lake Turawskie is an artificial reservoir on the Mała Panew River. Lake Turawskie
was selected for the preliminary project from among 14 objects of the Odra basin in
terms of the large-scale program called “The ecological state of barrier lakes in the Odra
river basin and works conducted towards its improvement”. The aim of the project,
financed by the Provincial Environment Protection Fund in Opole, is the evaluation of
the ecological state of Lake Turawskie, to obtain valuable information to serve in the
planning and selection of a method for its remediation. The necessity of conducting a full
inquisitorial campaign of Lake Turawskie results from the lack of authoritative
information on the subject of its pollution, participation and influence on specific types
of pollutants during the process of eutrophication.
The sources of pollution for Mała Panew River waters are supposed to be mainly
agricultural activity, municipal waste waters and industrial wastes. Industry, concentrated
in the upper and central part of the Mała Panew River basin, includes mining and
metallurgy of silver, zinc and lead, manufacture of cellulose, chemical production
(dyestuff for the textile industry, explosives), ferrous metallurgy and glass-works. Due to
this fact, the Mała Panew River supplies Lake Turawskie with polluted water and a large
quantity of sediments contaminated with heavy metals [6, 7].
In a previous study on 154 Lake Turawskie samples surface water, underground
water and bottom sediments were analysed for in total 33 chemical and physicochemical
parameters (pH, conductivity, dissolved oxygen, biological oxygen demand (BOD5),
chemical oxygen demand (COD), chloride, sulfate, dissolved silica, ammonia nitrogen,
nitrate(V) nitrogen, nitrite(III) nitrogen, Kjeldahl nitrogen, phenols, anionic detergents,
total iron, mercury, lead, copper, nickel, zinc, cadmium, manganese, total chromium,
chromium(VI), magnesium, sodium, potassium, calcium, alkalinity, total hardness,
turbidity, total content of solutes, and suspended matter). As seen, the chemical analysis
includes the standard water quality parameters, heavy metals, and some organic
components [8]. In addition, GC/MS target analysis of PCB congeners, organochlorine
pesticides, and PAH was performed on this large set of samples [9].
As a supplement to the previously obtained large set of analytical target parameter
data, the present study was designed to search by GC/MS non target screening analysis
for previously unrecognized toxic organic compounds using a comparatively small
number of sediments preselected by toxicological testing.
Integrated approach - the effective tool for pollution level control of sediments …
315
Lake Turawskie sediment samples
The drilling campaign in the bottom of the Lake Turawskie was carried out in the
period between June and September 2004. The sediment samples were collected from
34 sediment cores (from 0.07 to 8.00 m in length). In total 154 samples were tested
using: gas chromatography coupled to mass spectrometry (PCB congeners,
organochlorine pesticides, PAH), inductively coupled plasma - atomic emission
spectrometry (Cr, Zn, Cu, Ni, V, Fe, Mn, Al, Li), electrothermal atomic absorption
spectrometry (Cd, Pb), hydride generation atomic absorption spectrometry (As), cold
vapour atomic absorption spectrometry (Hg), trueness of which was examined by
appropriate reference materials analyses, ie SRM 1941a (Organics in Marine Sediment,
NIST) in the case of PCBs and PAHs, and MESS-2 (Marine Sediment, NRCC) in the
case of heavy metals [9].
The next step of the sample testing was the performance of a series of measurements
allowing for an assessment of acute toxicity of all samples taken [9].
This report presents results of the GC/MS non target screening analysis and
toxicological testing of 11 selected sediments sampled at 6 points and 1 to 3 different
depths [m]: TZB 6 (0.00÷0.60), TZB 8 (0.00÷0.13), TZB 25 (0.00÷0.35), TZB 25
(0.35÷0.70), TZB 53 (1.00÷2.00), TZB 53 (2.00÷3.00), TZB 76 (0.00÷1.00), TZB 76
(2.00÷3.00), TZB 81 (0.00÷0.35), TZB 81 (0.35÷2.00) and TZB 81 (2.00÷3.00).
Acute toxicity tests of aqueous extracts with bioluminescent bacteria
Freeze-dried sediments were mixed with a four-times greater volume of water and
shaken (24 h). After centrifugation (10 min/3000 rpm) and filtration (0.45 µm pore
diameter fiberglass filters, Millipore), pH and specific conductivity were measured using
a pH-metric electrode EPP-3 (Elmetron) and a waterproof multipurpose instrument,
CX - 401 (Elmetron, and conductometric sensor Type CD-2, No. 1530), respectively.
As a result of this process, clear and colourless aqueous extracts of sediments were
obtained. The extracts were subjected to toxicological studies against selected indicating
organisms.
Acute toxicity was determined using the Microtox® Model 500 (Microtox,
Strategic Diagnostics Inc., USA). As bioindicator organisms, the bioluminescent bacteria
from the comma bacillus group (Vibrio fischeri class) were applied. Toxicity
measurements of aqueous eluates obtained from sediments were conducted in accordance
with the requirements of the International Standard Organization (ISO) (PN-EN ISO,
2002). The pH of the samples was measured and, when necessary, adjusted to
pH 6.0÷8.0 using NaOH or HCl. Tests were carried out according to the Basic Test
Protocol of Microtox with four concentrations and one control in each test and
a measurement of the inhibition of bioluminescence of freeze-dried Vibrio fischeri
bacteria after 30 min. The obtained data was used to calculate the EC20 and EC50, which
are the median sample concentrations that cause, respectively, a 20% and 50% reduction
in bacteria bioluminescence. Internal quality control tests using zinc sulphate
(ZnSO4⋅7H2O) were run periodically during the study [10, 11]. TII50 values were
evaluated on the basis of the formula [12]: TII50 = 100/EC50
316
Preparation of sediment extracts for organic analysis
Freeze-dried sediment was mixed with a four-times greater volume of water and
shaken (24 h). After centrifugation (10 min/3000 rpm) and filtration (0.45 µm,
fiberglass) the aqueous sediment-extract was shaken (10 min) with 1 cm3 CH2Cl2. The
dichloromethane-extract was reduced to 300 mm3 and used for GC/MS-analysis directly,
as well as after separation into fractions of increasing polarity by silica gel
chromatography (after [13], modified). Borosilicate glass columns (12 mm i.d., 79 mm
height, Baker) were dry packed with 2 g silica gel (Baker, type 70245) held between two
PTFE frits. The silica was activated for 15 h at 180°C before use. The sample solutions
were adjusted to 600 mm3 with n-pentane, and elemental sulfur was removed by addition
of activated copper powder. 500 mm3 of the samples were taken from the supernatant
and separated by liquid-solid chromatography over silica columns into fractions:
1. fraction: 5 cm3 n-pentane;
2. fraction: 8.5 cm3 n-pentane/ CH2Cl2 (95/5 v/v);
3. fraction: 5 cm3 n-pentane/ CH2Cl2 (90/10 v/v), then 5 cm3 n-pentane/CH2Cl2
(40/60 v/v);
4. fraction: 20 cm3 CH2Cl2.
The fractions were concentrated to 50 mm3. Final assays were performed by
GC/MS-analysis on an HP 5890 gas chromatograph (280°C interface temperature),
equipped with on-column injector, retention gap (2.5 m x 0.53 mm), and a BPX-5 fused
silica capillary column (30 m x 0.25 mm i.d. x 0.25 µm film) coupled to a VG 70SE
mass spectrometer (EI+, 70 eV, 200°C source temperature), scanning from m/z 500 to
m/z 35 at 0.9 s cycle time with 0.2 s interscan delay. Temperature programmed analyses
(60°C, 3 min hold, 5°/min heating rate to 280°C, 10 min hold) were run by injection of
1 mm3 sample with helium as the carrier gas at ∼35 cm/s linear velocity.
This paper reports on the toxicity assessment and the analysis of organic compounds
exemplified on 11 sediment samples collected at different depths from bores made at the
bottom of Lake Turawskie. The ecotoxicological data set was compiled using sediment
extracts, and GC/MS analysis was performed on dichloromethane extracts prepared from
the tested aqueous solutions.
In Table 1 measurement results are presented of acute toxicity (using the Vibrio
fischeri bacteria) determined for sediment samples collected from analytical bores made
in the Turawski basin. In this table there were additionally placed Toxicity Impact Index
(TII50) values.
An evaluation of the ecotoxicological quality of analysed sediment samples was
conducted on the basis of a classification system, developed within the scope of the
ARGE-Elbe project [14]. This system classifies sediment samples from a I-V
ecotoxicological quality classification on the basis of a percentage value (PE) of the
observed toxic effect (Table 2). In this case the percentage effect is luminescence
inhibition.
317
Table 1
Acute toxicity measurement results with Vibrio fischeri bacteria conducted for aqueous extracts of sediment
samples collected from analytical bores made in the Turawski basin (EC20(50) - the concentration of a sample
that causes 20 or 50% of the maximal inhibition of bioluminescence; low values indicate high toxicity and
high values lack of toxicity, TII50 - Toxicity Impact Index)
No. sample
TZB 6
TZB 8
TZB 25
TZB 25
TZB 53
TZB 53
TZB 76
TZB 76
TZB 81
TZB 81
TZB 81
Bore-hole
depth [m]
0.00÷0.60
0.00÷0.13
0.00÷0.35
0.35÷0.70
1.00÷2.00
2.00÷3.00
0.00÷1.00
2.00÷3.00
0.00÷0.35
0.35÷2.00
2.00÷3.00
Luminescence
inhibition [%]
99
52
59
89
43
72
99
100
100
100
46
EC20 (0.5 h)
[%]
3
24
20
5
15
23
3
0
0
11
28
EC50 (0.5 h)
[%]
5
76
60
16
100
49
8
0
0
18
95
Class of
toxicity
V
IV
IV
V
III
V
V
V
V
V
III
TII50
20.00
0.13
1.67
6.25
1.00
2.04
12.50
5.56
1.05
Table 2
Ecotoxicity classification (PE - percentage effect, WFD - EU Water Framework Directive) of sediments
formulated within the ARGE-Elbe project [14]
Class of toxicity
Values of PE
I
II
III
IV
V
≤ 15%
> 15% PE ≤ 30%
> 30% PE ≤ 50%
> 50% PE ≤ 70%
> 70%
Environmental state
(in respect of WFD)
very good
good
moderate
weak
bad
Lake sediments contain thousands of substances of natural and anthropogenic origin.
A certain number of them are toxic and may constitute a risk for an aquatic ecosystem.
Compounds were identified by comparing their mass spectra with those of own, library,
and literature data [15], and by taking into account gas chromatographic retention
behaviour.
Fig. 1. GC/MS total ion chromatogram (background corrected, retention time - min) of TZB 6,
fraction 1, n-C11- n-C31 (arrows), 18-norabietan (#), other peaks mainly branched alkanes,
alkylcyclopentanes, alkylcyclohexanes
318
Aqueous extraction of the sediment samples was applied to preferentially enrich
a polar bioavailable organic fraction, assumed to cause the toxic effects observed. The
dichloromethane extracts of these aqueous phases, however, contained a majority of
less-polar organic compounds commonly found in moderately polluted limnic sediments.
The total ion chromatograms (denoted as RI33 in the corresponding figures) as well as
reconstructed traces of characteristic ion mass to charge ratios (m/z) of a given sediment
extract fraction of different sediments were very similar, so large differences between
samples of different toxicity classes were not apparent. An exemplary overwiew of the
organic compounds the fractions of the sediment extracts are typically composed of is
given in Figures 1-3a using the arbitrarily chosen sediment TZB 6. In addition to
bio- and geochemical markers an anthropogenic contribution was visible in n-alkane
patterns (TZB 6 fraction 1, Fig. 1), phenylalkanes and di-iso-propylnaphthalenes [16]
(TZB 6 fraction 2). Pollution with chlorinated pesticide residues and PCB was low, while
PAH-contents were high (TZB 6 fraction 3). Diarylhydrocarbons, in part known from
styrene/α-methylstyrene- and xylene-chemistry, were characteristic components of these
sediments, and therefore, may form specific anthropogenic marker compounds.
fraction 2, n-alkenes C23, C25, C27 (arrows), 18-norabietan (#) and related diterpenoid
geochemical marker compounds, mono- and diaromatic hydrocarbons
Fig. 2a. Mass spectrum of 18-norabietan (from peak at retention time 29:29 min)
319
A more polar fraction with sedimentary aldehydes, methylketones, esters,
PAH-ketones and quinones was usually contaminated with omnipresent compounds, like
phthalates, and with 2-ethylhexyl-3,5,5-trimethylhexanoate of obscure origin.
fraction 3, polycyclic aromatic compounds (1 - phenanthrene, 2 - fluoranthene, 3 - pyrene),
traces of chlorinated hydrocarbons (HCH and o,p- and p,p-DDE, arrows), geochemical
marker compounds
Fig. 3a. Mass spectra of the triterpenoid geochemical marker compounds 3,3,7-trimethyltetrahydrochrysene (upper) and 3,4,7-trimethyl-tetrahydrochrysene (lower)
Conclusions
As a consequence of the very complex composition of the sediment extracts
produced by water treatment and subsequent dichloromethane extraction, it was not
possible to correlate the observed toxicity effects with specific organic pollutants in the
sediments. A more selective sediment work up accompanied by toxicity testing in each
step may help to produce more complete information about the chemical causes of
toxicological effects. However, non target screening analysis of complex sediment
320
extracts provides characteristic patterns of marker compounds [17] reflecting a manmade and natural influence.
Acknowledgments
This research was financially supported by the Department of Scientific Research of
the Polish Ministry of Scientific Research and Information Technology - grant
no. N 305 091 31/3422 and grant no. N N305 3468 33.
This research was supported by the European Union within the European Social
Fund in the framework of the project “InnoDoktorant - Scholarships for PhD students,
I edition”.
References
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
Wang Ch., Wang Y., Kiefer F., Yediler A., Wang Z. and Kettrup A.: Ecotoxicol. Environ. Saf., 2003, 56,
211-217.
Brack W., Altenburger R., Ensenbach U., Möder M., Segner H. and Schüürmann G.: Arch. Environ.
Contam. Toxicol., 1999, 37, 164-174.
Wolska L., Sagajdakow A., Kuczyńska A. and Namieśnik J.: Trends Anal. Chem., 2007, 26, 332-344.
Scheurell M., Franke S. and Hühnerfuss H.: Intern. J. Environ. Anal. Chem., 2007, 87, 401-413.
Reineke N., Bester K., Hühnerfuss H., Jastorff B. and Weigel S.: Chemosphere, 2002, 47, 717-723.
Skowronek A.: Project of integrated measuring-investigative research on the load of contaminated
sediments in a water reservoir (the case study of the "Turawa” reservoir). Conference Materials:
Problems concerning water resource protection in the Odra river basin. RZGW Wrocław, 05.2002,
Szklarska Poręba (in Polish).
Skowronek A. and Wróbel F.: Final report on the research done within the project „Estimation of the
Ecological State of Turawskie Lake for the Preparation of Corrective Measures”, performed from
15.10.2003 to 14.12.2004 (in Polish).
Kuczyńska A., Wolska L., Simeonov V., Tsakovski S., Zahov S. and Namieśnik J.: J. Balkan Ecol.,
2006, 9, 267-281.
Simeonov V., Wolska L., Kuczyńska A., Gurwin J., Tsakovski S., Protasowicki M. and Namieśnik J.:
Trends Anal. Chem., 2007, 26, 332-331.
Microtox Analyzer Manual, Tigret, Poland, 2006.
PN-EN ISO 11348:2002. Water quality - Determination of the inhibitory effect of water samples on the
light emission of Vibrio fischeri (Luminescent bacteria test) - Part 3: Method using freeze-dried bacteria.
Polish Committee for Standardization, Warsaw, Poland.
Farré M., García M.-J., Tirapu L., Ginebreda A. and Barceló D.: Anal. Chim. Acta, 2001, 427, 181-189.
Franke S., Schwarzbauer J. and Francke W.: Fresenius J. Anal. Chem., J. Balkan Ecol., 1998, 360,
401-413.
Reincke H., Schulte-Oehlmann U., Duft M., Markert B., Oehlmann J. and Stachel B.: Biologisches
Effektmonitoring an Sedimenten der Elbe mit Potamopyrgus antipodarum und Hinia (Nassarius)
rericulata (Gastropoda: Prosobranchia). ARGE-Elbe (2001).
Compound identification based on own, library, and literature data: MassLib V9.3-106, ©Max Planck
Inst. for Coal Research & MSP Kofel; A. Ensminger, Thesis, Univ. Strasbourg 1977; C. Spyckerelle,
A. Greiner, P. Albrecht, G. Ourisson: J. Chem. Research (M), 3746-3754 and 3801-3809 (1977).
321
[16] Franke S., Grunenberg J. and Schwarzbauer J.: Int. J. Environ. Anal. Chem., 2007, 87, 437-448.
[17] Ricking M., Schwarzbauer J. and Franke S.: Water Res., 2003, 37, 2607-2617.
KOMPLEKSOWA OCENA STOPNIA ZANIECZYSZCZENIA
OSADÓW DENNYCH JEZIORA TURAWSKIEGO
* Instytut Chemii Organicznej, Uniwersytet w Hamburgu
** Katedra Chemii Analitycznej, Wydział Chemiczny, Politechnika Gdańska
*** Zakład Toksykologii Środowiska, Międzywydziałowy Instytut Medycyny Morskiej i Tropikalnej
Akademia Medyczna w Gdańsku
Abstrakt: Turawski zbiornik retencyjny został wytypowany do projektu pilotażowego spośród 14 obiektów
zlewni Odry w ramach programu: „Stan ekologiczny jezior zaporowych w dorzeczu Odry i działania na rzecz
jego poprawy”. Celem projektu jest ocena stanu ekologicznego Jeziora Turawskiego dla uzyskania
niezbędnych informacji mających służyć do zaprojektowania i wyboru metody jego remediacji. Jezioro
Turawskie jest nizinnym zbiornikiem retencyjnym na rzece Mała Panew. Potencjalnymi źródłami
zanieczyszczeń wód Małej Panwi jest działalność rolnicza, ścieki komunalne i odpady przemysłowe.
Działalność przemysłowa (również w przeszłości) w zlewni rzeki obejmuje między innymi: eksploatację
i hutnictwo srebra, cynku i ołowiu, produkcję celulozy, produkcję chemiczną w (tym barwników dla
przemysłu włókienniczego i materiałów wybuchowych), hutnictwo żelaza oraz hutnictwo szkła. Celem
przedstawionych badań była ocena poziomu zanieczyszczenia osadów jeziora oraz poszukiwanie korelacji
pomiędzy oszacowaną toksycznością a wynikami analiz chemicznych (na przykładzie wybranych próbek).
W ekstraktach z próbek osadów oznaczano między innymi związki organiczne. Do izolacji związków
o charakterze polarnym zastosowano ekstrakcję rozpuszczalnikiem (dichlorometan). Do rozdzielenia
związków wykorzystano chromatografię gazową, a następnie analizowano je w detektorze spektrometrii mas
(GC-MS; tryb pracy: SCAN). Badania ekotoksykologiczne przeprowadzono, korzystając ze standardowego
testu bakteryjnego Microtox® wykorzystującego zjawisko bioluminescencji bakterii z rodzaju przecinkowców
(gatunek Vibrio fischeri).
Słowa kluczowe: chromatografia gazowa, związki organiczne, osady denne, Microtox®, Vibrio fischeri
Vol. 16, No. 3
2009
Małgorzata Anna JÓŹWIAK*1 and Marek JÓŹWIAK*
INFLUENCE OF CEMENT INDUSTRY ON ACCUMULATION
OF HEAVY METALS IN BIOINDICATORS
WPŁYW PRZEMYSŁU CEMENTOWEGO NA KUMULACJĘ
METALI CIĘŻKICH W ORGANIZMACH BIOINDYKATORÓW
Abstract: Biomonitoring which is more and more widely used and data from measurements enables
comprehensive tracking of hazards and positive changes in areas under anthropopressure. Among many
diverse bioindicators the lichens are commonly used. The lichens are used to detect heavy metals,
radionuclides, air pollutants, polynuclear aromatic hydrocarbons (PAH) and polychlorinated biophenyls
(PCB). Because of high air pollution in urban areas, occurrence of the lichens is very limited. These
bioindicators can be used by transplantation method. The purpose of the study was to determine accumulation
of heavy metals coming from cement dust and morphological changes of lichen thalli transplanted in Kielce.
The lichens were transported on branches from Borecka Forest. The branches were hanged in three points of
the city. After 3-month exposure, the lichens were prepared for chemical analysis to determine Cd, Pb, Fe and
Zn which was conducted with IL 251 atomic absorption spectrophotometer (AAS). Metals were determined at
the following wavelengths: cadmium - λ = 228.8 nm, lead - λ = 217 nm, copper - λ = 324.7 nm,
iron - λ = 248.3 nm, zinc - λ = 213.9 nm. The highest average concentrations of Zn, Cd, Cu and Pb were
observed during cold period of 2006 - I quarter (41.69 mg·kg–1 d.m.) and IV quarter (41.77 mg·kg–1 d.m.)
whereas in warm period (II and III quarter) the concentration of metals was less and amounted to
39.92 mg·kg–1 d.m. and 37.80 mg·kg–1 d.m. respectively. Penetration of heavy metals and cement dust
particles together with water into thallus results in die-back of algae layer cells what causes necrotic changes
visible in outside structure of thallus.
Keywords: air pollution, heavy metals, bioindicators, lichens
Air quality control by technical equipment that is instrumental monitoring is
nowadays one of the methods of environmental pollution assessment. Biomonitoring
which is more and more widely used and data from measurements enables complete
tracking of hazards and positive changes in areas under anthropopressure. Advantage of
this environmental control system is that not only numerical data are obtained but first of
all information on types of hazards to organisms are acquired. Early warning system
against influence of toxins on organisms can be developed based on observation of
*
Independent Department of Environment Protection and Modelling, The Jan Kochanowski University of
Humanities and Sciences in Kielce, ul. Świętokrzyska 15, 25-406 Kielce, Poland, tel. +48 041 349 64 18
1
Corresponding Autor: [email protected], [email protected]
324
Małgorzata Anna Jóźwiak and Marek Jóźwiak
bioindicators [1, 2]. Among many diverse bioindicators the lichens are commonly used
[3-6]. The lichens are used to detect heavy metals, radionuclides, air pollutants,
polynuclear aromatic hydrocarbons (PAH) and polychlorinated biophenyls (PCB).
Suspended dust particles settled on lichen thallus surface are common air pollutants. In
Polish terminology suspended dust term applies to sulphate and nitrate aerosols, carbon
black and mineral particles. Power plants, municipal heat supply system and
transportation are emission sources of suspended dust in Kielce. Besides, cement dust
from cement plants located approx. 10 km from the city centre is a significant source of
pollutants for the city, too. Particles of 10 µm (PM10) and 2.5 µm (PM2.5) diameter
containing PAH and heavy metals are major part of particles emitted by above emission
sources.
Gołuchowska and Strzyszcz [7] revealed that cement dust contains high amounts of
Zn, Cd, Mo, Cu, Pb and Hg.
The purpose of the study is to determine accumulation of heavy metals coming from
cement dust in lichen thalli transplanted in Kielce and changes in their morphological
structure.
Study area
Acording to division of Poland into physiogeographical regions by Kondracki [5],
Kielce belongs to: subprovince: Małopolska Upland (342), macroregion: Kielecka
Upland (342.3), mesoregion: Świętokrzyskie Mountains (342.3.34-35), microregion:
Kielecko-Łagowski Vale (342.347) - Figure 1.
Fig. 1. Location of Kielce with regard to physiogeographical units by Kondracki (1998):
1 - Lubelsko-Lwowska Upland, 2 - Środkowopolskie Lowlands, 3 - North Podkarpacie
4 - Śląsko-Krakowska Upland, 342. - Małopolska Upland, 342.34-35 - Świętokrzyskie
Mountains
Influence of cement industry on accumulation of heavy metals in bioindicators
325
Based on topoclimatic conditions for the city, an average annual air temperature is
7.0°C, relative humidity is 80%, precipitation is 724 mm, and growing season averages
265 days. Location of the city in Kielecko-Łagowski Vale contributes to wind direction
and distribution. Winds are observed during 10 months a year with majority of western
winds and their frequency amounts to 43.2% [8]. Remaining observed winds are: south
and south-eastern (25.4%) and north and north-eastern (7.4%). Wind speed has
significant influence on air pollutant spreading. Kielce is rated among areas of middle
and low windiness with average value of 2.8 m·s–1. Location of the city in poor ground
circulation belt and occurrence of so-called weather calm being an area of polluted air
stagnation decides the low airing of the city. The lowest airing zones are formed in areas
that are perpendicular to wind main directions. So-called wind shadow formed in this
way is the essential element favouring accumulation of pollutants. South-western winds
dominated in the research period (Fig. 2).
2006
N
30%
25%
NW
NE
20%
15%
10%
5%
W
0%
E
SW
SE
S
Fig. 2. Wind rose for Kielce in 2006
Because of high air pollution in urban areas, occurrence of the lichens is very limited.
These bioindicators can be used by transplantation method. This method was applied in
Kielce by transplanting lichens transported on branches from Borecka Forest
(north-eastern Poland). Research was carried out in 2006. Branches were placed on tree
trunks at a height of 2 m above ground level in selected research surfaces which were
municipal recreation areas (Public Park, Park of Culture and Recreation (Park Kultury
i Wypoczynku), Kielecki Bay) - Figure 3. In each research point three branches were
exposed. Exposure lasted 3 months and research was repeated four times. Obtained data
enabled to perform analysis of accumulation of heavy metals and analysis of changes in
bioindicator morphological structure during one year what was important with regard to
seasonal changes of emission and meteorological parameters.
326
Fig. 3. Fragment of the map of Kielce with points of exposure of lichens
Description of research object
Lichen Hypogymnia physodes (L.) Nyl. is commonly used in monitoring researches
because it meets all requirements for biological tests. Physiological sensitivity,
widespread occurrence and availability are its features. It is rated among leafy lichens
found on tree bark. It forms irregular rosette-shaped thalli that adhere closely to the
substratum thanks to undulated lower cortex. A colour of thallus surface depends on
environmental conditions. At a low relative air humidity it is steel-grey and decreases its
volume. When the humidity increases it becomes grey-green or intense green, spongy
and swollen. An anatomical structure of thalli is heteromeric and is characterised by
layered arrangement of fungal and algal cells. Algae Trebouxia gelatinosa or T. jamessi
have cocoon-shaped structure with well-developed chloroplast. It is laid in subcortical
layer formed of compact hyphae of class Ascomycetes - sac fungi (Phot. 1, 2).
327
Phot. 1. Morphological structure of thallus Hypogymnia physodes (Phot. M.A. Jóźwiak)
Phot. 2. Layered anatomical structure of Hypogymnia physodes (Phot. M.A. Jóźwiak)
Tested material (lichen thalli) collected after exposure was torn out of substratum,
tree bark residues were cleaned off and the material was chemically analysed for heavy
metals: Pb, Zn, Fe, Cu, Cd using IL 251 atomic absorption spectrophotometer (AAS).
The analyses were carried out in Environmental Protection Section of Kielce University
of Technology.
Determination of heavy metals
Dried thalli were grinded and 0.5 kg of each sample was weighed out. The analytical
samples were put into quartz crucible and poured over with 10 cm3 of nitric(V) and
chloric(VII) acids mixture in 4:1 ratio [4]. The poured samples were left for 24 hours at
room temperature and then they were mineralised in electric bath for three weeks till
a light and clear solution was obtained. After vaporizing to dryness the samples were
infiltrated and topped with redistilled water up to 10 ml. Blank tests of reagents were
prepared in the same way. In such prepared solutions in acetylene-air flame, using
IL 251 atomic absorption spectrophotometer (AAS) heavy metals were determined at the
following wavelengths: cadmium - λ = 228.8 nm, lead - λ = 217 nm, copper λ = 324.7 nm, iron - λ = 248.3 nm, zinc - λ = 213.9 nm.
The concentration of each metal was expressed in mg·kg–1 of dry matter.
328
Observations with scanning electron microscope
The observations were conducted in FEI QUANTA 200 scanning electron
microscope with EDS type microanalizer and image digital recording. Lichen thalli
scraps selected for observation were fixed in 2% glutaric aldehyde and then the
preparation was dehydrated in ethyl alcohol (30÷96%) and acetone. In order to remove
water from the sample without thallus deformation thus preserving its original structure,
a dryer for preparations with critical point transition effect (POLARON CPD (Critical
point driver)) was used. Before microscope observation the sample was dusted with
carbon and gold in IEE - 4C Vacuum Evaporator. A thin layer of carbon conductor
allowed to carry electric charge off. A layer of noble metal (gold) hindered electrons to
penetrate deeply and allowed to get higher resolution image. Point or area chemical
analyses of parenchyma layer and upper cortex of thalli Hypogymnia physodes were
carried out with EDS type microanalizer.
Results
Meteorological conditions during 2006 which significantly contributed to
accumulation of heavy metals in exposed lichens Hypogymnia physodes are presented in
Table 1.
Table 1
Description of meteorological conditions in Kielce in 2006
Months
I
II
III
IV
V
VI
VII
VIII
IX
X
XI
XII
T
[oC]
–5.0
–3.3
–0.4
9.6
13.8
17.5
23.0
17.6
17.0
11.6
6.7
3.3
RH
[%]
74.5
88.8
81.9
65.7
60.2
63.7
46.8
75.9
67.9
73.0
85.7
81.0
Rainfall
[mm]
9.0
37.5
47.6
34.8
51.5
43.5
1.0
113.8
28.0
38.6
73.5
27.3
The analysis of chemical composition of lichen thalli exposed in recreational areas
in Kielce for Zn, Cd, Cu and Pb showed that the highest average concentrations of these
elements were observed during cold period of 2006 - I quarter (41.69 mg·kg–1 d.m.) and
IV quarter (41.77 mg·kg–1 d.m.) whereas in warm period (II and III quarter) the
concentration of metals was less and amounted to 39.92 mg·kg–1 d.m. and
37.80 mg·kg–1 d.m., respectively. These results indicate the influence of intense heating
season in residential area as well as increased and incomplete combustion of fuel in
vehicles on accumulation level in bioindicator thalii. Meteorological conditions during I
and IV quarter (low temperature, increased relative air humidity, south-western winds)
played a major part in carrying heavy metals on cement dust particles. Growing season
was of significant importance in translocation of pollutants. For woody dicotyledons the
329
growing season is a leafless period what causes lack of natural barrier against deposition
of pollutants. The analysis of average concentrations of heavy metals (Zn, Cd, Pb and
Cu) in individual points of bioindicator exposure showed that the highest accumulation
was in Kielecki Bay area (58.59 mg·kg–1 d.m.), Public Park (44.88 mg·kg–1 d.m.) and
Park of Culture and Recreation (17.42 mg·kg–1 d.m.) - Table 2.
Table 2
Average concentration of heavy metals (Zn, Cd, Cu and Pb) in thalli Hypogymnia physodes in Kielce in 2006
Time and exposition place
Kielecki Bay
Public Park
Park of Culture and Recreation
(PCR)
Mean
I quarter
II quarter
62.53
46.2
III quarter IV quarter
mg·kg–1 d.m.
55.88
54.32
61.63
45.49
43.34
44.48
Mean
16.34
18.39
15.74
19.21
17.42
41.69
39.92
37.8
41.77
40.30
58.59
44.88
Such distribution of accumulation of heavy metals in lichen thalli indicates the
presence of two sources of pollutant emission. Kielecki Bay and Public Park are located
near intense motor traffic routes that is why heavy metals accumulated in lichen thalli
from these areas derive directly from automobile exhausts. Location of exposure points
on wind direction from cement plant area indicates that cement dust is also a source of
heavy metals. Photographs from scanning electron microscope revealing numerous
pollutants coming from cement plant (Phot. 3, 4) prove transportation of metals together
with cement dust. Microanalysis of pollutants visible on thallus surfaces performed with
EDS type microanalizer indicates the presence of Ca, Al, Fe and Cu (Fig. 4).
Phot. 3. Dust pollutants on surface of thallus Hypogymnia physodes (magn. 800x)
(Phot. M.A. Jóźwiak)
330
Phot. 4. Calcareous rose on
(Phot. M.A. Jóźwiak)
surface
of
thallus
Hypogymnia
physodes
(magn.
4000x)
Exposure points of lichens in Park of Culture and Recreation are located far from
roads and traffic routes. Average values of Pb, Cu, Zn and Cd for four quarters of 2006
amounted to 17.42 mg·kg–1 d.m. what constitutes 14.4% of all metals deposited in thalli
in all exposure points.
Fig. 4. Average concentration of heavy metals (Pb, Cu, Zn and Cd) in thalli Hypogymnia physodes
exposed in Kielce in 2006
331
Determination of quarterly values of accumulation of individual heavy metals was an
important aspect of conducted analyses. The highest concentrations were observed for
Fe - 132.54 mg·kg–1 d.m. in IV quarter and 132.27 mg·kg–1 d.m. in I quarter, the lowest
concentrations for Cd in II quarter - 7.55 mg·kg–1 d.m. Analysis of accumulation of
heavy metals in thallus Hypogymnia physodes presented in Figure 5 indicates upward
trend of concentration in I and II quarter for each tested metal.
I
II
III
IV
140
mg*kg-1 s.m.
120
100
80
60
40
20
0
Zn
Cd
Cu
Pb
Fe
Fig. 5. Average quarterly concentration of Zn, Cd, Cu, Pb and Fe in thallus Hypogymnia physodes
exposed in Kielce in 2006
Fig. 6. Percentage of heavy metals in thallus Hypogymnia physodes in quarters of 2006
332
Cu is an exception and its value in cold period (months I-III and X-XII) amounted to
6.29 and 8.4 mg·kg–1 d.m. whereas it increased in warm period (II and III quarter) and
amounted to 11.73 and 13.79 mg·kg–1 d.m. respectively. The markedly higher
concentration of Pb was also observed in cold period months what indicates a significant
contribution of means of transport and residential heating systems (low ambient
concentration) to air pollution with heavy metals. During periods with low temperatures,
motor vehicles consume more fuel especially when starting up, particularly those parked
in the streets what is common in Poland. Percentage of Pb compared with other metals
during cold period amounts to 16% for I quarter and 15% for IV quarter whereas during
warm months it remains at the constant level and amounts to 14%
(Fig. 6).
Phot. 5. Surface of thallus Hypogymnia physodes with visible pollutants (magn. 3000x)
(phot. M.A. Jóźwiak)
Phot. 6. Cross-section of thallus with visible lack of algal layer (magn. 400x) (phot. M.A. Jóźwiak)
Photographic documentation of thallus Hypogymnia physodes made with scanning
electron microscope showed numerous particles of anthropogenic pollutants
accumulating on dorsoventral surface (dorso-ventrally flattened), heteromeric structure
333
of thallus (Phot. 5). Thick-walled fungal cells should be a protective layer for photobiont
cells found inside thallus. They are apoplastic transportation routes for water in
fungus-fungus and fungus-alga system which under polluted air conditions are carriers of
anthropogenic particles. This process was described by Garty [9].
Penetration of heavy metals and cement dust particles together with water into
thallus results in die-back of algae layer cells (Phot. 6) what causes necrotic changes
visible in outside structure of thallus (Phot. 7).
Phot. 7. Blackening and losses in thallus of lichen Hypogymnia physodes (phot. M.A. Jóźwiak)
Conclusion
Research on pollution of the air by heavy metals using lichen Hypogymnia physodes
as the bioindicator revealed that under urban conditions two periods of different pressure
on the environment can be distinguished: the cold period (I and IV quarters) of increased
emission of pollutants to the air and warm period (II and III qarters) in which the
emission is lower. It is linked to increased human living activity during the cold period
(low emission) and longer start-up of motor vehicles caused by low temperatures what is
related with higher fuel consumption and higher emission of pollutants. Air pollution
increases under such conditions. Depending on type of industry dominating in a given
region, other emission sources can be found taking Kielce as an example. Because of
334
majority of wind directions towards the city, the cement industry developed in the
surroundings provides additional pollutants including heavy metals deposited in cement
dust. Organisms exposed to such pollutants accumulate particles containing heavy metals
on their surface or inside their organisms.
References
Burton M.A.S.: Biological monitoring of environmental contaminants, MARC Rep. 32. Monitoring and
Assessment Research Centre, King’s College London, University of London, London 1986.
[2] Conti M.E. and Cecchetti G.: Environ. Pollut., 2001, 114, 471-492.
[3] Rühling A. and Tyler G.: Water, Air, Soil Pollut., 1973, 2, 445-455.
[4] Pilegaard K., Rasmussen L. and Gyddesen H.: J. Appl. Ecol., 1979, 16, 843-853.
[5] Kondracki J.: Physiogeographical regions in Poland. PWN Warsaw 1998 (in Polish).
[6] Jóźwiak M.: Accumulation of heavy metals and morphological changes In halli of Hypogymnia
physodes (L.) Nyl. Lichen. Natural Environ. Monit., 2007, 8/07, 51-56 (in Polish with English
summary).
[7] Gołuchowska B. and Strzyszcz Z.: Ecol. Chem. Eng., 1999, 6(2-3), 217-227.
[8] Żarnowiecki G.: The occurrence of fog and glazed frost against the background of synoptic situations
and circulation types by the example of Kielce. Kielce Studies 1998, 3, 51-65 (in Polish with English
summary).
[9] Garty J., Levin T., Lehr H., Tomer S. and Hochman A.: J. Atm. Chem., 2004, 49, 267-289.
[10] Sawicka-Kapusta K., Zakrzewska M., Gdula-Argasińska J.: Air Pollution 2005, 82, 465-475
[1]
WPŁYW PRZEMYSŁU CEMENTOWEGO NA KUMULACJĘ
METALI CIĘŻKICH W ORGANIZMACH BIOINDYKATORÓW
Samodzielny Zakład Ochrony i Kształtowania Środowiska
Uniwersytet Humanistyczno-Przyrodniczy Jana Kochanowskiego w Kielcach
Abstrakt: Coraz szerzej stosowany biomonitoring wraz z danymi uzyskanymi z pomiarów instrumentalnych
daje pełną możliwość śledzenia zarówno zagrożeń, jak i pozytywnych zmian zachodzących na terenach
będących pod wpływem antropopresji. Spośród wielu różnorodnych biowskaźników powszechnie stosowane
są porosty. Wykorzystuje się je do wykrywania stężeń metali ciężkich, radionuklidów, zanieczyszczeń
gazowych, wielopierścieniowych węglowodorów aromatycznych (WWA) i polichlorowanego bifenolu (PCB).
Ze względu na duże zanieczyszczenia powietrza w obszarach aglomeracji miejskich występowanie bioty
porostowej jest bardzo ograniczone. Istnieje możliwość wykorzystania tych biowskaźników metodą
transplantacji. Celem niniejszego opracowania było określenie poziomu kumulacji metali ciężkich
pochodzących z pyłów cementowych oraz zmian morfologicznych w plechach porostów transplantowanych
w Kielcach. Porosty przywożono z Puszczy Boreckiej na gałązkach, które rozwieszano
w trzech punktach w mieście. Po trzymiesięcznej ekspozycji porosty przygotowywano do analizy chemicznej
na zawartość Cd, Pb, Cu, Fe i Zn, którą wykonywano z użyciem spektrofotometru absorpcji atomowej IL 251
(AAS). Metale oznaczono przy następujących długościach fal: kadm - λ = 228,8 nm, ołów - λ = 217 nm,
miedź - λ = 324,7 nm, żelazo - λ = 248,3 nm, cynk - λ = 213,9 nm. Największe średnie stężenia Zn, Cd, Cu
i Pb występowały w zimnym okresie 2006 roku - I kwartał (41,69 mg·kg–1 s.m.) i IV kwartał
(41,77 mg·kg–1 s.m.), podczas gdy w okresie ciepłym (II i III kwartał) stężenie metali było mniejsze,
odpowiednio 39,92 i 37,80 mg·kg–1 s.m. Efektem wnikających wraz z wodą do wnętrza plechy metali ciężkich
oraz cząstek pyłu cementowego jest obumieranie komórek warstwy algowej, co powoduje nekrotyczne zmiany
widoczne w budowie zewnętrznej plechy.
Słowa kluczowe: zanieczyszczenie powietrza, metale ciężkie, bioindykatory, porosty
Vol. 16, No. 3
2009
Adam SMOLIŃSKI*1 and Natalia HOWANIEC*
SUSTAINABLE PRODUCTION
OF CLEAN ENERGY CARRIER - HYDROGEN
ZRÓWNOWAŻONA PRODUKCJA
CZYSTEGO NOŚNIKA ENERGII - WODORU
Abstract: The state-of-the-art in biological hydrogen production methods is presented with a special focus on
the process of the anaerobic fermentation of organic wastes. The recently reported levels of hydrogen yields in
laboratory scale bioreactors and main challenges on the way to commercial implementations of biological,
fermentative hydrogen production systems are given.
Keywords: hydrogen, biological production, anaerobic fermentation, organic waste
Introduction
Nowadays, over 80% of the global energy production is based on fossil fuels
combustion processes, inherently combined with emission of contaminants, such as COx,
NOx, SOx, CxHy, carbon black, ash, tars and organic compounds. Depletion of global
fossil fuels resources as well as an increasing environmental awareness made the research
society search new, environmentally friendly, economically attractive and commonly
accessible energy carrier. According to analysts hydrogen is likely to become such an
ideal energy carrier in the medium-term perspective. Hydrogen is the most abundant
element in the universe, the lightest one (0.09 g per dm3) and of a considerably heat of
combustion (10 MJ/m3) [1]. Furthermore, water is the only hydrogen combustion
product, which makes it an extremely attractive fuel in terms of environmental
protection. Hydrogen may be stored in gaseous, liquid or solid (metal hydrides) form and
transported by pipelines, with losses smaller than in case of electricity transport. Up to
date hydrogen is widely used in hydrogenation processes, chemical removal of oxygen
traces (corrosion prevention), as a rocket engine fuel and as a cooling medium in electric
generators systems [2, 3]. Hydrogen production is based mainly on fossil fuels, biomass
and water. Natural gas comprises over 90% of the first group of hydrogen production
*
Department of Energy Saving and Air Protection, Central Mining Institute, pl. Gwarków 1,
40-166 Katowice
1
Corresponding Author: email: [email protected], tel. 032 259 22 52, fax 032 259 65 33
336
Adam Smoliński and Natalia Howaniec
base. Steam reforming of methane is conducted catalytically at the temperature of
1100°C and results in generation of hydrogen and carbon dioxide. These gases are also
the main products of coal gasification. At present, the technologies of coal gasification
combined with separation of hydrogen and sequestration-ready carbon dioxide
constitutes the subject of extensive research works worldwide.
However, energy demanding and emission generating thermochemical and
electrochemical hydrogen production processes can hardly be considered sustainable. An
alternative solution may lie in an application of biological methods, which means
employing natural microorganisms, which produce hydrogen as one of their metabolic
products. These processes in majority are conducted at ambient temperature and
pressure, which implies lower system energy demand. They also create new possibilities
for renewable energy resources utilization. The most promising in these terms seems to
be an anaerobic fermentation process, combining renewable-based clean energy carrier
production with organic waste utilization in environmentally friendly way.
Biological methods of hydrogen production
Biological hydrogen production has been scientifically recognized for over a century
now. Basic research on microbiological hydrogen production processes were undertaken
in the twenties and applied in the seventies of the 20th century. Although these were
mainly focused on photosynthesis systems, among the microbiological methods of
hydrogen production besides water biophotolysis (microalgae) and photofermentation
(photosynthesizing bacteria) one can also distinguish a very promising in terms of
commercial implementation, dark anaerobic fermentation (anaerobic heterotrophic
bacteria) [4-7] (Fig.1). Applying biological methods of hydrogen production in fuel cells
supply systems [4, 8-11] as well as organic waste-based hydrogen production as a fuel
for transport, heating and electricity generation systems [4, 12, 13] are seriously
considered, notwithstanding a commercial scale installation of these types are still
missing.
Below brief characteristics of biophotolysis and anaerobic fermentation processes is
given.
Hydrogen production in biophotolysis of water
The process of a direct biophotolysis consists in a decomposition of water molecule
in a photosynthetic system with solar energy and parallel liberation of electrons reducing
hydrogenase (see Fig.1).
Green algae in an anaerobic environment may either use hydrogen as electrons’
donor in a process of carbon dioxide assimilation or produce hydrogen. The process of
electrons transfer from water molecule via two photosystems to hydrogenase through an
electron carrier (ferredoxine) is less efficient than carbon dioxide reduction and is
inhibited (hydrogenase inhibition) by even low oxygen concentrations. Electrons are
liberated from the photosystem II with photon energy and transferred to ferredoxine with
the energy absorbed by photosystem I. Hydrogenase absorbs electrons directly from the
reduced ferredoxine, which leads to hydrogen liberation. Many algae (in particularly
green algae) produce hydrogen after the incubation period in dark, anaerobic conditions,
during which hydrogenase is synthesized and activated. Such algae put in light, anaerobic
Sustainable production of clean energy carrier - hydrogen
337
conditions, produce relatively high amounts of hydrogen until the photosynthesis process
with oxygen generation and carbon dioxide assimilation is restored [1, 8]. The main
obstacle on the way to a commercial implementation of the process is the problem of
hydrogenase inhibition by oxygen, irreversibly deactivating hydrogen production system
and promoting oxygen-dependant hydrogen absorption [6, 15]. To ensure the required
level of partial oxygen concentration in a bioreactor, below 0.1%, large volumes of
diluting gas would be needed, implying high costs of power consumption for gas
transport [14]. In the process of indirect biophotolysis by blue algae, hydrogen is
synthesized according to the reaction:
6H 2 O + 6CO 2 photon
 energy

→ C 6 H12 O 6 + 6O 2
(1)
C 6 H12 O 6 + 6H 2 O photon
 energy

→ 12H 2 + 6CO 2
(2)
Fig. 1. Schema of a direct biophotolysis process. Based on [14]
Various enzymes are involved in blue algae hydrogen metabolism: nitrogenase,
catalyzing production of hydrogen as a by-product of nitrogen reduction to ammonia,
hydrogenase, catalyzing hydrogen oxidation by nitrogenase and hydrogenase which may
both synthesize and oxidize hydrogen [8, 16].
Hydrogen production in the process of anaerobic fermentation - the principles
The anaerobic fermentation is a process of substrate molecule (organic compounds)
degradation and transformation, during which one of the products is oxidized and the
other one is reduced as follows: carbohydrates organic acids + H2 + CO2 [17].
The process of methane fermentation has been commonly used since the beginning
of the 20th century in municipal, agricultural and industrial waste treatment, wastewater
treatment and excess sludge treatment, in thousands installation all around the world.
Microorganisms involved in the methane fermentation comprise of four trophic groups:
1) bacteria hydrolyzing biopolymers such as carbohydrates, proteins and fats to soluble
polymers: simple sugars, amino acids, multihydric alcohols and organic acids, 2)
338
acidogenic bacteria, among the others common anaerobes of Clostridium sp.,
transforming organic compounds to volatile fatty acids (formic, acetic, propionic,
butyric, valeric, caproic acids), alcohols (ethanol, butanol), lactic and succinic acids,
carbon dioxide and hydrogen, 3) acetogenic bacteria, transforming acidogenic phase
products into acetates, hydrogen and carbon dioxide and 4) methanogenic bacteria,
transforming primary carbon compounds, hydrogen and acetates into methane and
carbon dioxide. The latest group is sensitive to the temperature variation of ±2°C,
presence of oxygen (over 0.01 g/m3) and pH variation (below 6 and over 8). This
characteristics as well as lack of sporulation are of the greatest practical importance for
the aforementioned process of the biological, anaerobic hydrogen production.
Homoacetogenic bacteria may produce hydrogen on simple sugars or use hydrogen and
carbon dioxide as metabolic substrates. A biogas is the main product of the anaerobic
treatment of organic waste. It typically contains 65÷70% of methane, 25÷30% of carbon
dioxide and traces of hydrogen and other compounds, such as: hydrogen sulfide,
ammonia, volatile organic compounds and steam. Its heating value, depending on
methane content, is about 20 MJ/m3 [18]. The biogas as the product of the anaerobic
fermentation is utilized mainly for heat and power generation for treatment plants needs.
Greenhouse gas emission from methane combustion process is lower than in case of
other fossil fuels. It is also used in methanol production (biofuels) and syngas production.
Power generation in solid oxide fuel cells is considered to be its prospective application
[12, 19-21]. Systems based on an intensified hydrogen production in the first phase of the
anaerobic fermentation process and on methanogenesis inhibition seems to be the next
step in biomass-based clean energy carriers’ production. The fermentation end products
should be subsequently converted into additional amounts of hydrogen or forms of
energy to increase the overall process efficiency. The process of two-stage anaerobic
fermentation for intensified and stable hydrogen (I stage) and methane (II stage)
production is reported as the one of presently the highest potential for market application
[10, 22, 23] - Figure 2. Other options of the second stage process considered, though
nowadays still uneconomic, are photobioreactors (degradation of complex organic
substrate to fatty acids in the dark anaerobic fermentation phase followed by the
photofermentation stage) - Figure 3 - and microbial fuel cells [23].
Fig. 2. Schema of a local hydrogen and methane production and utilization system based on the
process of biomass fermentation [5]
339
Hydrogen production in the process of photofermentation
Purple non-sulphur bacteria in nitrogen-depleted environment produce hydrogen in
nitrogenase-catalyzed process, using photon energy and organic acids [8, 24]. The
process is characterized by comparatively low hydrogen production efficiency, connected
with nitrogenase characteristics (low molecular activity: 6.4 s–1, high energy demand for
enzyme synthesis), low solar conversion and need of complex, large-surface, anaerobic
photo-bioreactors [14].
Fig. 3. Schema of hydrogen production in the two-stage process of anaerobic fermentation and
photofermentation, combined with food industry and agricultural waste utilization. Based on
[25]
Hydrogen production in the process of anaerobic fermentation the state-of-the-art
The anaerobic fermentation is a complex process involving differentiated
interdependencies between various groups of bacteria. It is characterized by significant
impact of process conditions, including the kind and concentration of by-products, on
growth of particular groups of microorganisms, their metabolism, and resulting from the
above - final process products. The structure and biochemistry of enzymes as well as the
physiology of microorganisms producing hydrogen in the anaerobic fermentation process
is well recognized. Numerous reports on laboratory research works in batch cultures and
continuous flow reactors aiming at the maximization of presently achievable hydrogen
production efficiency and identification of possible improvement areas are available. In
these terms the most important factors are optimization of growth conditions and activity
of acidogenic and acetogenic bacteria with the inhibition of methanogenic
340
microorganisms’ activity. The latest is achieved by pre-treatment of sludge used as
a source of mixed bacteria cultures, short retention times of 8÷12 h, and/or low pH of
5÷6. The best and most widely applied method of sludge pretreatment is a heat-treatment
[26], though considered less attractive in terms of technical application than acid or alkali
dosing. Reports of tests with mixed and pure bacteria cultures (Enterobacter sp., Bacillus
sp., Clostridium sp., or newly isolated) [eg 27-31], at various temperatures (mesophile
25÷40°C, thermopile: 40÷65°C, extremophile: 65÷80°C and hipethermophile: over 80°C
[eg 9, 32-34]), various initial pH, with or without pH adjustment during the test [27,
35-37] are available. The experiments reported were carried out for various substrates,
substrate loadings and nutrient solution composition, including at least nitrogen and
phosphorus sources in the ratios COD:N of 11:1-73:1 and 73:1-970:1 for COD:P [23].
An impact of a kind and a dose of buffering compounds on hydrogen production
efficiency was also tested. The increase in hydrogen production was observed in a mixed
culture with appropriate dose of phosphates or carbonates. The possibility of
optimization of the process with Na2HPO4 as phosphorus donor and buffering agent and
inhibitory impact of increasing dose of NH4HCO3 due to increase in carbon dioxide
concentration and/or toxic impact of ammonia, resulting from the salt decomposition was
reported [38]. No direct relation between hydrogen output and food industry waste COD
were observed by van Ginkel et al [13]. An increase in hydrogen production was
observed with an increasing temperature at the range of 25÷40°C. The maximal
concentrations of hydrogen at increasing temperatures were reached with decreasing
concentrations of iron salts (800÷25 g FeSO −4 /m 3 ). The shortest lag phase was observed,
as expected, for the temperature of 35°, optimum for biocatalytic activity of enzymes
involved in the process [39]. The optimization of the C/N ratio in a nutrient medium with
sucrose as a carbon source, in a mixed culture was also analyzed by Lin and Lay [40].
The optimum C/N ratio in the studied terms was 47. Lower content of nitrogen caused
shift of the metabolism in the direction of reduced compounds; higher content resulted in
ammonia concentration increase to the levels toxic for microorganisms. An increase in
magnesium and iron sources dose were found influencing positively the hydrogen
production levels at the range of 10÷80 g/m3 of MgCl2⋅6H2O and FeSO4⋅7H2O,
respectively, in batch culture at 35°C for pure strain B49 isolated from anaerobic
activated sludge [26]. Substrate and product inhibition as well as methods of their
preventing were also studied [33]. The highest non-inhibiting substrate concentration is
reported to be about 30 g/dm3 for glucose and sucrose [23]. Sparging with nitrogen and
mixing are widely applied as system elements aiming at avoiding product inhibition and
process efficiency enhancement. Nitrogen sparging led to 68% increase in hydrogen
production rate per mol of substrate in a mixed culture, with hydraulic retention time,
HRT = 8.5 h, pH 6.0 and glucose concentration of 10 g/dm3 [41]. Interestingly, no
inhibiting effect on hydrogen production of hydrogen partial pressure of 101 kPa was
reported by Wang et al [30] in batch cultures of B49 at 350C on glucose. The levels of
hydrogen evolved were comparable for hydrogen and nitrogen - sparged cultures but
decreased significantly, of about 40%, in case of sparging with CO2. Similar effect was
also reported by Park et al [42]. The impact of bacteria immobilization in batch and
continuous, mixed and pure cultures was also tested. In case of mixed cultures activated
carbon showed better properties than sponge or clays, ensuring higher bacteria
341
concentrations (and consequently higher hydrogen production) and better bed stability
when short retention times were used [43]. It was also proved of better performance
when compared with polivynyl alcohol as a support medium [43, 44] and best medium
for granular sludge development [45]. Artificial immobilization matrix were also used
[46]. Rice straw turned out to be better immobilization matrix than bagasse and coconut
fibre for Enterobacter cloacae [47]. First attempts of hydrogen separation from batch
municipal sludge fermentation derived biogas with mixed culture applying palladium
membranes resulted in 85÷90% separation. Volatile fatty acids accumulation in the
membrane was the main disadvantage observed [48]. Polymer membranes were also
tested [49].
Laboratory research works’ results confirm the need of applying operating
parameters values ensuring effective control of the process towards formation of such
products as acetic and butyric acids, occurring in exponential bacteria growth phase and
accompanied by production of hydrogen and carbon dioxide, and not towards propionate,
lactate acids and alcohols. This could be achieved by applying: short retention times and
the lowest possible pH, in practice on the level between 5 and 6 [5, 23, 50, 51], though
lower pH of about 4.5 was also reported as feasible but with slightly lower hydrogen
yields [52-56]. The maximal hydrogen production rate should be theoretically achieved
with acetic acid as the final product according to the reaction:
C 6 H12 O 6 + 2H 2 O → 2CH 3COOH + 2CO 2 + 4H 2
(3)
which gives the maximum production of 4 mol H2/mol glucose. Practically, however, the
optimum is correlated with the mixture of acetic and butyric acids in a fermentation
process by Clostridia Sp. (eg: C. Pasteuranum, C. Butyricum):
C 6 H12 O 6 → CH 3CH 2 CH 2 COOH + 2CO 2 + 2H 2
(4)
and part of the substrate is used for biomass growth and other metabolic products
generation [23, 51]. The molar ratio of butyric acid to acetic acid was reported as
potentially useful in estimating the predicted hydrogen molar yield. It should also be
noted that higher levels of acetate might also imply that a negative phenomena of
homoacetogenesis or acetate production from H2 and CO2 took place [57].
The development of a reliable commercial-scale biological hydrogen production
systems requires applying easily accessible, mixed and pre-treated (with heat, acid or
alkali) cultures sources in order to eliminate methanogenic bacteria and activate the
clostridial spores [51] as few reports are available on methanogenesis-free process with
no sludge pre-treatment [39, 58]. The highest molar hydrogen yields were observed for
Clostridium sp. (according to various sources: 1.61÷2.36 mol H2/mol glucose [5],
0.37÷2.00 mol H2/mol glucose [51], 2.36 H2 mol/mol glucose [8], 1.13÷2.32 mol/mol
glucose [29] and 1.65÷2.45 mol H2 /mol glucose [59]. Recently higher levels of 1.8÷2.5
mol H2/mol glucose were reported by Wu et al [46] for acid treated sludge from
a secondary sedimentary tank of a wastewater treatment plant immobilized on POE
(polyethylene - octane elastomer) in a fluidized bed reactor and of 2.20÷3.21 mol H2/mol
glucose by Datar et al [60] for pre-heated sewage sludge derived mixed cultures and corn
stover pretreated with high-pressure steam as a substrate, at 35°C in a batch, stirred
reactor. The optimal substrates for hydrogen bio-production are carbohydrates (glucose
and its isomers, hexoses and polymers, such as starch, cellulose). Notwithstanding the
342
cognitive value of research works on pure carbohydrate substrates (eg glucose, sucrose,
starch), enriched with phosphorus and nitrogen sources, the practical value for the
development of commercial systems have tests applying other biomass resources, of
appropriate carbohydrates content and low demand in terms of their pre-treatment, in
particularly waste products (eg from fruit and vegetables processing industry,
confectioners, sugar refineries, organic municipal waste) [12, 13, 25, 61-63]. Tests on
protein and fat rich organic waste (undergoing hydrolysis and fermentation, like
carbohydrates to fatty acids, transformed into do acetates, CO2 and H2) showed their
about twenty times lower potential for hydrogen production in comparison with
carbohydrates [64].
Fermentative hydrogen production - challenges on the way
to commercial application
Photosynthesis-based hydrogen production is still economically uncompetitive [8,
59]. Hydrogen production rates in the process of direct biophotolysis, indirect
biophotolysis and photofermentation are about 0.07, 0.355 and 0.16 mol H2/m3h,
respectively [8]. The rate of hydrogen production in the anaerobic fermentation of about
120 mol H2/m3h [8] or even about 320 mol H2/m3h for activated carbon seeded granules
[45], 415 mol H2/m3h in a carrier-induced granular sludge bed reactor [65] and
670 mol H2/m3h in a stirred granular sludge bed reactor [66], give premises for
intensification of research works carried out since the 1980’ in order to develop basis for
commercially applied systems of organic waste fermentation to hydrogen. The most
important technological problems are fast hydrogen and carbon dioxide removal, and gas
separation (H2, CO2, CH4, H2S, NH3), bioreactor design optimization and bacteria
genetic modifications in order to increase reactivity of cellulase, hemicellulase, ligase
and hydrogenase as well as elimination of metabolic paths competitive to hydrogen
synthesis [5, 14, 67]. In terms of bioreactor design the most promising are the continuous
flow stirred tank reactors of higher molar hydrogen yield and higher stability of operation
and sequential upflow anaerobic sludge blanket reactors of higher volumetric hydrogen
production levels [23, 68]. The conditions for homoacetogenesis limitation, nutrient
requirements for process optimization and cost-effectiveness, more experimental data on
continuous operation on industrial complex substrates, more data on stirring effect, more
research on low-cost gas purification systems and assessment of the process in terms of
permissible dilution of the product gas are also required [23]. Research efforts should
also be focused on optimization of the two-stage process of hydrogen and methane
production in terms of enhanced stability and increased efficiencies with various
industrial wastes.
References
[1]
[2]
[3]
Das D. and Veziroglu T.N.: Hydrogen production by biological processes: a survey of literature.
Int. J. Hydrogen Energy, 2001, 26, 13-28.
Ramachandran R. and Menon R.K.: An overview of industrial uses of hydrogen. Int. J. Hydrogen Energy
E, 1998, 23, 593-598.
Veziroglu T.N.: Twenty years of the hydrogen movement 1974-1994. Int. J. Hydrogen Energy, 1995, 20,
1-7.
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
[28]
[29]
343
Claassen P.A.M., van Groenestijn J.W., Janssen A.J.H., van Niel E.W.J. and Wijffels R.H.: Feasibility of
biological hydrogen production from biomass for utilisation in fuel cells. Proc. 1st World Conference
and Exhibition on Biomass for Energy, Industry and Climate Change Protection. Sevilla, 2000,
http://www.biohydrogen.nl/everyone/6591.
Hawkes F.R., Dinsdale R., Hawkes D.L. and Hussy I.: Sustainable fermentative hydrogen production:
challenges for process optimization. Int. J. Hydrogen Energy, 2002, 27, 1339-1347
Melis A. and Melnicki M.R.: Integrated biological hydrogen production. Int. J. Hydrogen Energy, 2006,
31, 1563-1573.
Claassen P.A.M. and de Vrije T.: Non-thermal production of pure hydrogen from biomass:
HYVOLUTION. Int. J. Hydrogen Energy, 2006, 31, 1416-1423.
Levin D.B., Pitt L. and Love M.: Biohydrogen production: prospects and limitations to practical
application. Int. J. Hydrogen Energy, 2004, 29, 173-185.
van Groenestijn J.W., Hazewinkel J.H.O., Nienoord M. and Bussmann P.J.T.: Energy aspects of
biological hydrogen production in high rate bioreactors operated in the thermophilic temperature
range. Int. J. Hydrogen Energy, 2002, 27, 1141-1147.
Nishio N. and Nakashimada Y.: Recent development of anaerobic digestion processes for energy
recovery from wastes. J. Biosci. Bioeng., 2006, 103, 105-112.
Duerr M., Gair S., Cruden A. and McDonald J.: Hydrogen and electrical energy from organic waste
treatment. Int. J. Hydrogen Energy, 2007, 32, 705-709.
Angenent L., Karim K., Al-Dahhan M. H., Wren Brian A. and Domiquez-Espinoza R.: Production of
bioenergy and biochemicals from industrial and agricultural wastewater. Trends Biotechnol., 2004, 22,
477-485.
van Ginkel Steven W., Oh Sang-Eun and Logan B.E.: Biohydrogen gas production from food
processing and domestic wastewater. Int. J. Hydrogen Energy, 2005, 30, 1535-1542.
Hallenbeck P.C. and Benemann J.R.: Biological hydrogen production: fundamentals and limiting
processes. Int. J. Hydrogen Energy, 2002, 27, 1185-1193.
Lambert G.R. and Smith G.D.: Hydrogen metabolism by filamentous cyanobacteria. Arch. Biochem.
Biophys., 1980, 205, 36-50.
Smith G.D., Ewart G.D., Tucker W.: Hydrogen production by cyanobacteria. Int. J. Hydrogen Energy,
1992, 17, 695-698.
Kunicki-Goldfinger W.J.H.: Życie bakterii. Wyd. 6. WN PWN, Warszawa 1994.
Janosz-Rajczyk M.: Wybrane procesy jednostkowe w inżynierii środowiska. Wyd. Polit.
Częstochowskiej, Częstochowa 2004.
Chynoweth D.P., Owens J.M. and Legrand R.: Renewable methane from anaerobic digestion of
biomass. Renew. Energy, 2001, 22, 1-8.
Murphy J.D. and McKeogh E.: Technical, economic and environmental analysis of energy production
from municipal solid waste. Renew. Energy, 2004, 29, 1043-1057.
Shiga H., Shinda K., Hagiwara K., Tsutsumi A., Sakurai M., Yoshida K. and Bilgen E.: Large scale
hydrogen production from biogas. Int. J. Hydrogen Energy, 1998, 23, 631-640.
Cooney M., Maynard N., Cannizzaro C. and Benemann J.: Two-phase anaerobic digestion for
production of hydrogen-methane mixtures. Bioresour. Technol., 2007, 98, 2641-2651.
Hawkes F.R., Hussy I., Kyazze G., Dinsdale R. and Hawkes D.: Continuous dark fermentative hydrogen
production by mesophilic microflora: Principles and progress. Int. J. Hydrogen Energy, 2007, 32,
172-184.
Shi X.Y. and Yu H.Q.: Continuous production of hydrogen from mixed volatile fatty acids with
Rhodopseudomonas capsulata. Int. J. Hydrogen Energy, 2006, 31, 1641-1647.
Kapdan I. and Kargi F.: Bio-hydrogen production from waste materiales. Enzyme Microb. Technol.,
2006, 38, 569-582.
Mu Y., Yu H.Q. and Wang G.: Evaluation of three methods for enriching H2-producing cultures from
anaerobic sludge. Enzyme Microb. Technol., 2007, 40, 947-953.
Kumar N. and Das D.: Enhancement of hydrogen production by Enterobacter Cloacae. Process
Biochem., 2000, 35, 589-593.
Oh Y.-K., Seol E.-H., Kim J.R. and Park S.: Fermentative biohydrogen production by a new
chemoheterotrophic bacterium Citrobacter sp. Y19. Int. J. Hydrogen Energy, 2003, 28, 1353-1359.
Levin D.B., Islam R., Cicek N. and Sparling R.: Hydrogen production by Clostridium thermocellum
27405 from cellulosic biomass substrates. Int. J. Hydrogen Energy, 2006, 31, 1496-1503.
344
[30] Wang X.J., Ren N.Q., Xiang W.S. and Guo W.Q.: Influence of gaseous end-product inhibition and
nutrient limitations on the growth and hydrogen production by hydrogen - producing fermentative
bacterial B49. Int. J. Hydrogen Energy, 2007, 32, 748-754.
[31] Shin J.H., Hyun Yoon J., Eun K.A., Kim M.S., Sang J.S. and Park T.H.: Fermentative hydrogen
production by the newly isolated Enterobacter asburiae SNU-1. Int. J. Hydrogen Energy, 2007, 32,
192-199.
[32] Claassen P.A.M., Budde M.A.W., van der Wal F.J., Kadar Z., van Noorden G.E. and De Vrije T.:
Biological hydrogen production from biomass by thermophilic bacteria. Proc. Eur. Conf. Exh.
Biomass., Adam, 2002, http://www.biohydrogen.nl/everyone/20765.
[33] van Niel E., Pieternel W.J., Claassen A.M. and Stams A.J.M.: Substrate and product inhibition of
hydrogen production by the extreme thermopile, Caldicellulosiruptor saccharolyticus. Biotechnol.
Bioeng., 2003, 81, 255-262.
[34] Siriwongrungson V., Zeng R.J. and Angelidaki I.: Homoacetogenesis as the alternative pathway for H2
sink during thermophilic anaerobic degradation of butyrate under suppressed methanogenesis. Water
Res., 2007, 41, 4204-4210.
[35] Khanal K.S., Chen Wen-Hsing, Li L. and Sung S.: Biological hydrogen production: effects of pH and
intermediate products. Int. J. Hydrogen Energy, 2004, 29, 1123-1131.
[36] Lay J.J.: Modelling and Optimisation of anaerobic digested sludge converting starch to hydrogen.
Biotechnol. Bioeng., 2000, 68, 269-278.
[37] Mu Y., Yu H.Q. and Wang G.: A kinetic approach to anaerobic hydrogen-producing process. Water
Res., 2007, 41, 1152-1160.
[38] Lin C.-Y. and Lay C.H.: Effects of carbonate and phosphate concentrations on hydrogen production
using anaerobic sewage sludge microflora. Int. J. Hydrogen Energy, 2004, 29, 275-281.
[39] Zhang, Y. and Shen J.: Effect on temperature and iron concentration on the growth and hydrogen
production of mixed bacteria. Int. J. Hydrogen Energy, 2006, 31, 441-446.
[40] Lin C.Y. and Lay C.H.: Carbon/nitrogen effect on fermentative hydrogen production by mixed
microflora. Int. J. Hydrogen Energy, 2004, 29, 41-45.
[41] Mizuno O., Dindsdale R., Hawkes F.R., Hawkes D.L. and Noike T.: Enhancement of hydrogen
production from glucose by nitrogen gas sparging. Bioresour. Technol., 2000, 73, 59-65.
[42] Park W., Hyun S.H., Oh S.-E., Logan B.E. and Kim I.S.: Removal of headspace CO2 increases
biological hydrogen production. Environ. Sci. Technol., 2005, 39, 4416-4420.
[43] Chang J-S, Lee K.-S. and Lin P.J.: Biohydrogen production with fixed-bed bioreactors. Int. J. Hydrogen
Energy, 2002, 27, 1167-1174.
[44] Kim J.O., Kim Y.H., Ryu J.Y., Song B.K., Kim I.H. and Yeom S.H.: Immobilisation methods for
continuous hydrogen gas production biofilm formation versus granulation. Process Biochem., 2005, 40,
1331-1337.
[45] Lee K.-S., Wu J.-F., Lo Y.-S., Lo Y.-C., Lin P.-J. and Chang J.-S.: Anaerobic hydrogen production with
an efficient carrier-induced granular sludge bed bioreactor. Biotechnol. Bioeng., 2004, 87, 648-657.
[46] Wu K.J., Chang C.F. and Chang J.S.: Simultaneous production of biohydrogen and bioethanol with
fluidized-bed and packed-bed bioreactors containing immobilized anaerobic sludge. Process Biochem.,
2007, 42, 1165-1171.
[47] Kumar N. and Das D.: Continuous hydrogen production by immobilized Enterobacter cloacae IIT-BT
08 using lignocellulosic materials as solid matrices. Enzyme Microb. Technol., 2001, 29, 280-287.
[48] Nielsen A.T., Amandusson H., Bjorklund R., Dannetun H., Ejlertsson J., Ekedahl L.-G., Lundstrom I.
and Svensson B.H.: Hydrogen production from organic waste. Int. J. Hydrogen Energy, 2001, 26,
547-550.
[49] Teplyakov V.V., Gassanova L.G., Sostina E.G., Slepova E.V., Modigell M. and Netrusov A.I.: Lab-scale
bioreactor integrated with active membrane system for hydrogen production: experience and prospects.
[50] Chen C.C. and Lin C.Y.: Using sucrose as a substrate in an anaerobic hydrogen producing reactor.
Adv. Environ. Res., 2003, 7, 695-699.
[51] Sung S., Baskin L., Duangmanee T., Padmasiri S. and Simmons J.J.: Hydrogen production by anaerobic
microbial communities expose to repeated heat treatments. Proc. the 2002 US DOE Hydrogen Program
Review, 2002, NREL/CP-610-32405.
[52] Ren N., Li J., Li B., Wang Y. and Liu S.: Biohydrogen production from molasses by anaerobic
fermentation with a pilot-scale bioreactor system. Int. J. Hydrogen Energy, 2006, 31, 2147-2157.
345
[53] Ren N.Q., Li Y.F., Wang A.J., Li J.Z., Ding J. and Zadsar M.: Hydrogen production by fermentation:
review of a new approach to environmentally safe energy production. Aq. Ecosyst. Health Manage.,
2006, 9, 39-42.
[54] Khanal S.K., Chen W.-H., Li L. and Sung S.: Biohydrogen production in continuous flow reactor using
mixed microbial culture. Water Environ. Res., 2006, 78, 110-117.
[55] Ren N., Wang B. and Huang J.-C.: Ethanol-type fermentation from carbohydrate in high rate
acidogenic reactor. Biotechnol. Bioeng., 1997, 54, 428-433.
[56] Wang L., Zhou Q. and Li F.T.: Avoiding propionic acid accumulation in the anaerobic process for
biohydrogen production. Biom. Bioen., 2006, 30, 177-182.
[57] Hussy I., Hawkes F.R., Dinsdale R. and Hawkes D.L.: Continuous fermentative hydrogen production
from a wheat starch co-product by mixed microflora. Biotechnol. Bioeng., 2003, 84, 619-626.
[58] Hussy I., Hawkes F.R., Dinsdale R.M. and Hawkes D.L.: Continuous fermentative hydrogen production
from sucrose and sugarbeet. Int. J. Hydrogen Energy, 2005, 30, 471-483.
[59] Ust’ak S., Havrland B., Muñoz J.O.J, Fernández E.C. and Lachman J.: Experimental verification of
various methods for biological hydrogen production. Int. J. Hydrogen Energy, 2007, 32, 1736-1741.
[60] Datar R., Huang J., Maness P-Ch., Mohagheghi A., Czernik S. and Chornet E.: Hydrogen production
from the fermentation of corn stover biomass pretreated with a steam-explosion process. Int. J.
Hydrogen Energy, 2007, 32, 932-939.
[61] Fan Y.-T., Zhang Y.-H., Hou H.-W. and Ren B.-Z.: Efficient conversion of wheat straw wastes into
biohydrogen gas by cow dung compost. Biores. Technol., 2006, 97, 500-505.
[62] Lay J.J., Lee Y.J. and Noike T.: Feasibility of biological hydrogen production from organic fraction of
municipal solid waste. Wat. Res., 1999, 33, 2579-2586.
[63] Yokoi H., Maki R. and Hayashi S.: Microbial production of hydrogen from starch-manufacturing
waste. Biom. Bioen., 2002, 22, 389-395.
[64] Lay J.-J., Fan K.-S., Chang, J. and Ku C.H.: Influence of chemical nature of organic wastes on their
conversion to hydrogen by heat-shock digested sludge. Int. J. Hydrogen Energy, 2003, 28, 1361-1367.
[65] Lee K.-S., Lo Y.-C., Lin P.-J. and Chang J.-S.: Improving biohydrogen production in a carrier-induced
granular sludge bed by altering physical configuration and agitation pattern of the bioreactor.
[66] Wu S.-Y., Hung C.-H., Lin C.-N., Chen H.-W., Lee A.-S. and Chang J.-S.: Fermentative hydrogen
production and bacterial community structure in high rate anaerobic bioreactors containing
silicone-immobilised and self-flocculating sludge. Biotechnol. Bioeng., 2006, 93, 934-946.
[67] Milne T.A., Elam C.C. and Evans R.J.: Hydrogen from biomass State of the at and research challenges.
A Report for the International Energy Agency Agreement on the production and utilization of hydrogen
Task 16, hydrogen from carbon-containing materials, IEA/H2/TR-02/001,
http://www.osti.gov/energycitations/servlets/purl/792221-p8YtTN/native/792221.PDF.
[68] Gavala H.N., Skiadas I.V. and Ahring B.K.: Biological hydrogen production in suspended and attached
growth anaerobic reactor systems. Int. J. Hydrogen Energy, 2006, 31, 1164-1175.
ZRÓWNOWAŻONA PRODUKCJA
CZYSTEGO NOŚNIKA ENERGII - WODORU
Abstrakt: Przedstawiono przegląd stanu wiedzy w zakresie biologicznych metod produkcji wodoru ze
szczególnym uwzględnieniem procesu beztlenowej fermentacji odpadów organicznych. Zaprezentowano
aktualne dostępne dane literaturowe na temat osiąganego poziomu produkcji wodoru w instalacjach
laboratoryjnych oraz główne wyzwania stojące na drodze do zastosowań przemysłowych systemów
beztlenowej biologicznej produkcji wodoru.
Słowa kluczowe: wodór, biologiczna produkcja, fermentacja beztlenowa, odpady organiczne
Vol. 16, No. 3
2009
Krzysztof BARBUSIŃSKI*
FENTON REACTION CONTROVERSY CONCERNING THE CHEMISTRY
REAKCJA FENTONA - KONTROWERSJE DOTYCZĄCE CHEMIZMU
Abstract: There is something intriguing and at the same time fascinating that a simple reaction (of Fe2+ ions
with H2O2), which was observed by H.J.H. Fenton over 110 years ago, proves to be very difficult to describe
and understand. As yet the nature of the oxidizing species obtained in Fenton reaction is still a subject of
deliberation, which may be explained by the fact that it is very common in both chemical and biological
systems and in natural environment. It is a paradox that the Fenton reaction is successfully used in
environmental protection (for example in wastewater treatment and remediation of groundwater) and it is
thought to be a factor, which causes damage to biomolecules and plays a major role in the aging process and
a variety of diseases. This article presents a short review on radical and non-radical mechanisms of the Fenton
reaction postulated in literature, possible reaction pathways as well as various points of view in this field.
Keywords: Fenton reaction, Fenton reagent, Fenton chemistry, hydroxyl radical, ferryl ion
Introduction
The oxidation of organic substrates by iron(II) and hydrogen peroxide is called the
“Fenton chemistry”, as it was first described by H.J.H. Fenton who first observed the
oxidation of tartaric acid by H2O2 in the presence of ferrous iron ions [1]. Alternatively,
the name of “Fenton reaction” or “Fenton reagent” is often used. We know that the
Fenton reagent defined as a mixture of hydrogen peroxide and ferrous iron is currently
accepted as one of the most effective methods for the oxidation of organic pollutants.
The Fenton reagent has been known for more than a century but its application as
an oxidizing process for destroying hazardous organics was not applied until the late
1960s [2, 3]. After this time comprehensive investigations showed that the Fenton
reagent is effective in treating various industrial wastewater components including
aromatic amines [4], a wide variety of dyes [5-7], pesticides [8-10], surfactants [11-13],
explosives [14] as well as many other substances. As a result, the Fenton reagent has
been applied to treat a variety of wastes such as those associated with the textile industry,
*
Institute of Water and Wastewater Engineering, Silesian University of Technology, ul. Konarskiego 18,
44-100 Gliwice, Poland, tel. 032 237 11 94, email: [email protected]
348
Krzysztof Barbusiński
chemical manufacturing, refinery and fuel terminals, engine and metal cleaning etc. [7,
15]. The Fenton reagent can also effectively be used for the destruction of toxic wastes
and non-biodegradable effluents to render them more suitable for secondary biological
treatment [16]. Moreover, the importance of Fenton chemistry has been long recognised
among others in food chemistry and material ageing [17].
Currently we know that the efficiency of the Fenton reaction depends mainly on
H2O2 concentration, Fe2+/H2O2 ratio, pH and reaction time. The initial concentration of
the pollutant and its character as well as temperature, also have a substantial influence on
the final efficiency. Moreover, there is wide spread experience in the practical use of
Fenton reagent for degradation of organic substrates in wastewater and other wastes.
More than 110 years after the Fenton reaction was discovered we know that this
oxidation system is based on the formation of reactive oxidizing species able to
efficiently degrade the pollutants of the wastewater stream. The nature of these species is
still under discussion and it has been a subject of controversy in the past and recent
Fenton oxidation related literature [18-22]. Two reaction pathways for the first step of
Fenton chemistry have been advanced: a radical pathway, which considers an OH•
radical production and a non-radical pathway considering ferryl ion production [23].
This paper presents a short review on the radical and non-radical mechanisms of the
Fenton reaction postulated in literature. The possible reaction pathways and various
points of view in this field are also discussed.
Fenton chemistry - the controversies
Radical and non-radical pathways
Although the Fenton reagent has been known for more than a century and has been
proven long since as a powerful oxidant, the mechanism of the Fenton reaction is still
under intense and controversial discussion [18]. The radical (OH•) and non-radical
mechanism (mainly ferryl ion) of the Fenton reaction are discussed in literature. Two
years after Fenton’s death the hydroxyl radical mechanism was mentioned for the first
time in 1931 by Haber and Willstätter [24] in a paper on radical chain mechanisms [25].
They suggested that OH• could be produced by one-electron reduction of H2O2 by HO2•
(today known as a very slow reaction in the absence of catalytic redox cycling metals)
and that OH• could abstract hydrogen from a carbon-hydrogen bond and initiate radical
chain reactions [24]. Following on in 1932 Haber and Weiss suggested OH• production
by one-electron reduction of H2O2 by Fe2+ [26-28]. According to the classic
interpretation of Haber and Weiss [28], the reaction of iron(II) with hydrogen peroxide
(H2O2) in aqueous solution leads to the formation of radicals OH• and HO2• as active
intermediates in the reactions (1 and 2) described below [18, 29]. However, their paper is
not concerned with oxidation of organic compounds. The reaction (1) is called the
Fenton reaction (or classical Fenton reaction), although Fenton never wrote it [26].
In 1946, Baxendale, Evans and Park [30] suggested that OH• from reaction 1 adds to
carbon double bonds and can thereby initiate a polymerisation reaction. The original
mechanism of Haber and Weiss has been subsequently modified in 1951 by Barb et al
[31]. The free radical mechanism proposed by Barb et al [31] consists of the following
steps [29]:
Fenton reaction - controversy concerning the chemistry
349
Fe2+ + H2O2 → Fe3+ + OH− + OH•
(1)
OH + H2O2 → HO2 +H2O
(2)
•
3+
•
2+
+
Fe + HO → Fe + H + O2
(3)
Fe2+ + HO•2 → Fe3+ + HO2−
(4)
•
2
2+
3+
Fe + OH → Fe + OH
(5)
It is a chain reaction with step (1) serving as chain initiation, steps (4) and (5) as
termination and the cycle (1)-(2)-(3) forms the chain which is the site of O2 evolution
[29]. More than two decades later Walling [32] presented further evidence of the
involvement of hydroxyl radicals in the oxidation of various organic compounds by the
Fenton reagent [18].
According to the theory presented above the chemistry related to the use of Fenton
reagent is the chemistry of this radical. Therefore, taking into consideration that the
Fenton reaction can also involve several other cations of metals (Mn+), the processes
connected with the reactions similar to Fenton reaction may be characterized as follows
[33]:
•
−
(Mn+) + H2O2 → (Mn+1) + OH− + OH•
(6)
For a long time the importance of the Fenton reaction in the production of OH
radicals in solution has been a subject of controversy [23]. The hydroxyl radical
production by the Fenton reaction has been questioned by several studies suggesting that
the reaction between H2O2 and iron(II) produces the ferryl ion (FeO2+, an oxidizing
Fe(IV) species), which is then the active intermediate species in the Fenton chemistry.
Bray and Gorin (1932) [34] were the first to propose iron(IV) as the active intermediate
in the Fenton chemistry and they postulated that iron(II) and iron(III) are connected
through equilibrium. Bray and Gorin suggested the reactions (7) and (8) but their paper
was not concerned with the oxidation of organic substances [23, 26]:
Fe2+ + H2O2 → FeO2+ + H2O
(7)
2+
2+
FeO + H2O2 → Fe + H2O + O2
(8)
The mechanism for the decomposition of hydrogen peroxide by Haber and Weiss
had been also criticised by George [35] and Abel [36] by the late 1940s [37].
The aqueous ferryl species [Fe(IV)O]2+ has been shown to be a reactive oxidant,
exhibiting both single-electron hydrogen abstraction chemistry and two-electron
oxidation of alcohols to ketones [38]. Accumulated evidence shows that the ferryl
species [Fe(IV)O]2+ can be formed under a variety of conditions including those related
to the ferrous ion-hydrogen peroxide system known as the Fenton’s reagent [39].
Kremer [29] concluded that it is difficult to accept the existence of free radical
mechanism because this mechanism either in the formulation of Haber and Weiss or in
that of Barb et al, recognizes only Fe2+ and Fe3+ as the forms of iron in the system. In the
free radical mechanism, reaction (2) becomes insignificant at low [H2O2] as a mode of
reaction of OH•. Hydroxyl radical could then react with Fe2+ and produce Fe3+ (reaction
(9)). As an alternative, OH• could react with Fe3+ (reaction (10)):
Fe2+ + OH• → Fe3+ + OH−
(9)
350
Fe3+ + OH• → FeOH3+
(10)
If this reaction occurred it would be even more plausible to assume that the pair
Fe3+ + OH• (as products of reaction 1) would not become separated at all and the species
FeOH3+ would appear instead. It can be stated that the species FeOH3+ is merely the
protonated form of FeO2+ (FeO2+ + H+ → FeOH3+) [29].
Fenton reaction in biological systems
All animals need O2 for efficient production of the energy in mitochondria. This
requirement for O2 obscures the fact that it is a toxic mutagenic gas - aerobes survive
only because they have evolved antioxidant defences. The field of antioxidants and free
radicals is often perceived as focused around the use of antioxidant supplements to
prevent human disease. In fact, antioxidants and free radicals permeate the whole of life,
creating the field of redox biology. Free radicals are not all detrimental but not all
antioxidants are beneficial. Life is a balance between the two: antioxidants serve to keep
down the levels of free radicals, permitting them to perform useful biological functions
without too much damage [40].
Fig. 1. Schematic representation of the sequence of events involved in Fenton reaction [41]
(modified). Initially, electron donors can convert oxygen to superoxide anion ( O •2− ), which is
rapidly converted to hydrogen peroxide. Hydrogen peroxide can further form hydroxyl
radicals (OH•) or ferryl ion (FeO2+) in the actual Fenton reaction in the presence of ferrous or
cuprous ions (which are simultaneously oxidized to ferric or cupric ions). SOD - superoxide
dismutase; RH/R - reducing agent in oxidized and reduced form
All aerobes suffer damage when exposed to O2 concentrations not only higher than
normal, but also even at normal O2 levels. Many scientists believe that O2 toxicity is due
to excess formation of the superoxide radical O •2− . This is the superoxide theory of O2
toxicity [40]. Although oxygen is a powerful oxidant, the triplet ground state of dioxygen
constitutes a kinetic barrier for the oxidation of biological molecules, which are mostly in
the singlet state. However, the unpaired orbitals of dioxygen can sequentially
351
accommodate single electrons to yield O •2− , H2O2, the highly reactive OH• and water.
Superoxide radical ( O •2− ) dismutates (via spontaneous or enzyme-catalysed reactions) to
produce H2O2 (Fig. 1 [41]). Superoxide radical can also reduce and liberate Fe3+ from
ferritin or liberate Fe2+ from iron-sulphur clusters. Subsequently highly reactive oxygen
species can be formed via the Fenton reaction [42].
It is also commonly accepted that the oxidizing intermediates involved in Fenton
reactions cause damage to biomolecules and play a major role in the aging process and
a variety of diseases such as cancer [43]. The Fenton reaction has been found to be the
key reaction in the oxidation of membrane lipids, oxidation of amino acids and in the
reactions where biological reduction agents are present, such as ascorbic acid or thiols.
Its occurrence is also supposed in heart diseases, such as ischemia and reperfusion [33].
The nature of the species responsible for this damage is however still unclear. Most
studies implicate the highly reactive hydroxyl radical as responsible for the damage
[44-46] and other studies champion the involvement of high valent metal species [47,
48]. The reactions with Fe(IV) have been implicated in biological processes and
proposed to be involved in damage to the cellular components. For example, in the case
of Fe2+ chelates with ADP, ortho-phosphate, or EDTA, the oxidant formed from H2O2
behaves differently than it is expected for OH• and it has been proposed to be the ferryl
FeO2+. Caged or bound OH•, often denoted as [Fe–H2O2]2+ or [FeOOH]+, might also
account for the noted differences [42, 49]. Many scientists even question the importance
and occurrence of the Fenton reaction in biological systems due to supposedly low
concentrations of H2O2 and “free iron” in the systems. They also claim that the high and
indiscriminate reactivity of the hydroxyl radical limits its ability to diffuse and cause
more extensive damage to biomolecules [43].
Competitive kinetic studies have been performed to compare the reactivity of the
oxidizing intermediates generated in the Fenton reaction with authentic OH• generated by
radiolysis of water or photolysis of H2O2 [50]. Rahhal and Richter [51] examined
FeII(EDTA) oxidation and suggested that an oxidant other than OH• was generated in this
system. Rush and Koppenol [52], having studied a number of chelated iron complexes
using stopped-flow spectrophotometry, concluded that a metallo-oxo species was
generated in neutral solutions, while OH• was predominant in acidic solutions of
nonchelated iron. Sutton et al [53] arrived at the opposite conclusion that unchelated iron
generated a metallo-oxo species as the primary oxidant while OH• was predominant
when chelated iron was present. Several review articles and research papers have
suggested a rationalization for this discrepancy in which it is argued that under certain
conditions, the metallo-oxo species or OH• can be generated in both systems. A recent
study, based on the assumption that 5,5-dimethyl-1-pyrroline N-oxide (DMPO)–OH
adducts are formed solely from OH•, has suggested that there is more than one type of
oxidizing intermediate present, and that the ratio between the amount of OH• and
metallo-oxo species depends on the chelated ligand [49].
Yamazaki and Piette [54] are proposed three possible pathways of the Fenton
reaction. The dominant ones depend very much on the nature of the iron chelator being
used. These three reaction paths comprised production of hydroxyl radicals, ferryl
species, and nonoxidizing species, respectively. Prousek [55] has reviewed various
352
aspects of the participation of Fenton chemistry in biology and medicine. He also
concluded that both hydroxyl radical and ferryl ion can be formed under a variety of the
Fenton and Fenton-like reactions.
Fenton reaction in natural waters
In natural waters exposed to solar radiation, reactive intermediates are formed which
then take part in photooxidation reactions [33, 43]. The Fenton reaction is often
perceived as a possible source of OH• in sunlight waters [56, 57]. Other sources include
photolysis of nitrate(III) [58], nitrate(V) [59], metal to ligand-charge-transfer reactions
[60], photoFenton reactions [56] as well as dioxygen-independent organic sources [61].
Both H2O2 and Fe(II) are photochemically produced in these sunlight waters. H2O2 is
formed via the disproportionation of the superoxide (O2•−), produced by the reduction of
oxygen by photoexcited dissolved organic matter (DOM). The concentrations of H2O2
and O2•− may be further increased in their production by microflora [33]. Fe(II) on the
other hand is produced by the photoreduction of Fe(III), which may be O2 assisted. The
process is usually increased by complexation with the organic ligands such as DOM [62].
While several studies have suggested that OH• is the oxidizing species involved in
the oxidative processes connected with Fenton reaction, other possibilities have not been
ruled out [43]. For example, a study of the reduction of dissolved iron species by humic
acid has suggested that in addition to the OH• radical another oxidant may be involved in
the Fenton reactions in the seawaters at neutral pH (7.0-7.5) [63]. Studies on the
oxidation of arsenic [64] have indicated that OH• is involved in the oxidation of
arsenic(III) to arsenic(IV), which occurs readily at low pH, but that high-valent metal
species may be formed also at high pH, which does not readily oxidize arsenic(III). Other
studies [65] suggest that at nanomolar levels of Fe(II) the oxidation of Fe(II) by H2O2 in
the seawater predominantly involves the FeOH+ species at pH 6-8.
Possible mechanisms of the Fenton reaction
Many studies examining the nature of reactive oxidizing species in the Fenton
reaction have been conducted and many possible mechanisms of reaction were presented.
Some of them are presented below. As an example, the simple free radical pathway
scheme (Fig. 2) can be shown [43, 66] but the mechanism of the Fenton reaction has
been suggested to be more complicated than presented in Figure 2. Since iron has
a variable valency, its oxidation by H2O2 may occur via a one or two electron transfer
(reactions (11) and (12), respectively):
Fe(II) + H2O2 → Fe(III) + OH− + OH•
(11)
Fe(II) + H2O2 → Fe(IV) + 2 OH
(12)
Some studies therefore suggest that the classical Fenton reaction occurs using only
Fe(II) as an electron donor to H2O2. Such would be an outer sphere electron transfer
reaction with no direct bonding interactions between the electron donor and the acceptor,
(Mechanism I, Figure 3). On the other hand, recent studies have shown and favored the
inner sphere electron transfer mechanisms, which involve direct bonding between the
iron and H2O2. This interaction could produce a metal-peroxo complex, Fe(II) HOO
which may react further to generate either HO• radicals (one-electron oxidant) or
−
353
Fe(IV)O (two electron oxidant), (Mechanism II, Figure 3). The key question therefore is
which of these species is the major oxidant in these reactions [43].
Fig. 2. Basic free radical mechanisms for the Fenton and Haber-Weiss reaction [43, 66]
Fig. 3. Basic reactions and intermediates involved in the classic Fenton and the metal centered
Fenton reactions [43]
Various pathways have been proposed [19, 29, 67, 68] including: non-radical
mechanisms, radical mechanisms involving oxygen centred radicals and reactions of
354
highvalent metal species (Fig. 4). Due to the importance of Fenton reactions in biological
and environmental systems elucidation of the nature of species involved in these
reactions has been the subject of many studies. These studies have been carried out at
varying pH using both organic and inorganic metal complexes and employing a variety
of free radical techniques of analysis (usually indirect).
Fig. 4. Possible reaction pathways for the Fenton reaction in absence of organic substrates [43]
Fig. 5. Proposed non-radical mechanism for the Fenton reaction [29]
Kremer [29] proposed a non-radical mechanism for the Fenton reaction (Fig. 5). He
suggested that the reaction starts with the reversible formation of a primary intermediate
{Fe2+ ⋅ H2O2} from Fe2+ and H2O2 (exchange of a H2O molecule in the hydration shell of
Fe2+ ions by H2O2). A secondary intermediate FeO2+ is formed from the primary complex
by the loss of H2O. This species is the key intermediate in the reaction. It can react either
355
with Fe2+ ions to produce Fe3+ (k5) or with H2O2 to produce O2 (k4). FeO2+ can further
react with Fe3+ and form a binuclear species [FeOFe]5+ (k6). This species can react with
H2O2 to produce O2 (k7) or to decompose back to FeO2+ and Fe3+ (k8). Kremer pointed
out that there is an error in the analysis of Barb et al [31], because they assumed a steady
state is attained in [Fe2+] whereas in fact [Fe2+] goes to zero [1].
More recent studies [64, 69] show that the Fenton chemistry mechanism cannot be
restricted to the mechanism of Barb et al [31] or to the one of Bray and Gorin [34].
Indeed, these studies postulate the existence of an active intermediate, which should be
a weak acid at pKa around 2 providing OH• and iron(III) formation at low pH values or
ferryl ion at high pH values. This hypothesis explains the observed OH• radical
production for equimolar concentrations of diluted reagents in water and pH values lower
than 2 [64, 69, 70]. Thus, according to the pH value, the active intermediary is OH•
(radical pathway) or the ferryl ion (non-radical pathway) [23].
Ensing and co-workers [71] demonstrate the spontaneous formation of ferryl ion
(FeIVO2+) in an aqueous solution of iron(II) and hydrogen peroxide by means of first
principles molecular dynamics simulations confirming the model first proposed by Bray
and Gorin. Their simulations disfavour but do not rule out completely the Haber and
Weiss OH• radical mechanism (which is, especially in biochemistry, often taken as
synonymous to Fenton chemistry). In the initial step of the iron catalysed hydrogen
peroxide dissociation, a very short-lived OH• radical and the L–FeIII–OH− complex
always appears first. This radical has no independent existence as it abstracts a hydrogen
either immediately or in a short transfer via one or two solvent molecules from a water
ligand to form a dihydroxoiron(IV) complex, or even directly from the OH ligand to
form the ferryl ion; in both these cases neutralizing itself to a water molecule. When
other ligands than water molecules are used, such as chelating agents, the radical may
scavenge these ligands.
Fig. 6. Mechanistic presentation of possible reactions involved in the thermal Fenton reaction with
simplified notations used for the various iron complexes [18]
356
Bossmann et al [18] studied the degradation of 2,4-dimethylaniline (2,4-xylidine) by
means of the H2O2/UV method and both Fenton and photochemically enhanced Fenton
reactions. The comparison of the reaction products of 2,4-xylidine clearly demonstrated
that H2O2 photolysis and both Fenton reactions involved different reactive intermediates.
While hydroxylated aromatic amines were formed during H2O2 photolysis,
2,4-dimethylphenol was the most important intermediate in both Fenton and
photochemically enhanced Fenton reactions. The genesis of 2,4-dimethylphenol may
only be explained by an electron-transfer mechanism. The authors concluded that during
the reaction of Fe 2aq+ with H2O2 a cationic iron intermediate possessing an unusual charge
(most likely the ferryl ion Fe 4aq+ ) was formed. Reaction pathways shown in Figure 6 may
be significantly important to understand the mechanism of the Fenton reaction.
Summary
The Fenton reaction generally occurs in chemical and biological systems as well as
in the natural environment. The importance of Fenton chemistry has been long
recognised among others in food chemistry, material ageing and in environmental
engineering in particular. The nature of the oxidizing species obtained in Fenton reaction
is still a controversial subject. It is something intriguing and at the same time fascinating
that a simple reaction (of Fe2+ ions with H2O2), observed by H.J.H. Fenton over one
hundred years ago, proves to be very difficult to describe and understand. It is a paradox,
that the Fenton reaction is successfully used in environment protection (for example in
wastewater treatment and remediation of groundwater) and it is thought to be a factor,
which causes damage to biomolecules and plays a major role in the aging process and
a variety of diseases.
A lot of research was done to determine the nature of the species involved in Fenton
reactions at various systems and conditions such as the influence of pH and the presence
of ligands. Some researchers claimed that the results of this study clearly show that OH•
radical is a major species in the Fenton reaction. Another group of the scientists have
provided an alternative interpretation of the Fenton reaction mechanism including
formation of reactive oxidizing iron species such as ferryl ion. It is important to notice
that the high valent metal species are generally unavailable (especially at neutral or
acidic pH) from an independent source. Therefore, it is difficult to demonstrate their
involvement in Fenton reactions. The formation or involvement of the ferryl species in
the Fenton reactions is indirectly deduced from the presence of species having different
reactivity from that of the hydroxyl radical [49]. In addition, most of the studies done to
determine the nature of species involved in Fenton and Fenton-like reactions have been
found to be inconclusive due to the limitations in their methodology [43]. Hence it
appears that on the basis of these results it is difficult to clearly conclude which theory is
true.
Considering the fact that Fenton reaction is common in chemical, biological, and
environmental systems where conditions may be very diverse, it is highly probable that
there is more than one universal Fenton mechanism. It is possible that both hydroxyl
radicals and ferryl ions can coexist in Fenton chemistry (Fenton and Fenton-like
reactions) and depending on the environmental conditions or operating parameters, one
357
of them will predominate. Given the above doubts, it is desirable to carry out further
in-depth research either prove the above hypothesis or prove that there is only one
mechanism (radical or non-radical) of the Fenton reaction.
References
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
[28]
[29]
[30]
[31]
[32]
[33]
[34]
[35]
[36]
[37]
[38]
[39]
[40]
[41]
[42]
[43]
[44]
[45]
Dunford H.B.: Coordin. Chem. Rev., 2002, 233-234, 311-318.
Huang C.P., Dong C. and Tang Z.: Waste Manage., 1993, 13, 361-377.
Neyens E. and Baeyens J.: J. Hazard. Mat., 2003, B98, 33-55.
Casero I., Sicilia D., Rubio S. and Pérez-Bendito D.: Water Res., 1997, 31, 1985-1995.
Kuo W.G.: Wat. Res., 1992, 26, 881-886.
Nam S., Renganathan V. and Tratnyek P.G.: Chemosphere, 2001, 45, 59-65.
Barbusiński K.: Polish J. Environ. Stud., 2005, 14, 281-285.
Huston P. L. and Pignatello J.J.: Water Res., 1999, 33, 1238-1246.
Barbusiński K. and Filipek K.: Polish J. Environ. Stud., 2001, 10, 207-212.
Ikehata K. and Gamal El-Din M.: J. Environ. Eng. Sci., 2006, 5, 81-135.
Lin S.H., Lin C.M. and Leu H.G.: Water Res., 1999, 33, 1735-1741.
Kitis M., Adams C.D. and Daigger G.T.: Water Res., 1999, 33, 2561-2568.
Perkowski J., Jóźwiak W., Kos L. and Stajszczyk P.: Fibres & Text. East. Eur., 2006, 14, 114-119.
Ming-Jer Liou, Ming-Chun Lu and Jong-Nan Chen: Water Res., 2003, 37, 3172-3179.
Bigda R.J.: J. Adv. Sci. Eng., 1996, 6, 34-37.
Chen R. and Pignatello J.J.: Environ. Sci. Technol., 1997, 31, 2399-2406.
Strlič M., Kolar J. and Pihlar B.: Acta Chim. Slov., 1999, 46, 555-566.
Bossmann S.H., Oliveros E., Göb S., Siegwart S., Dahlen E.P., Payawan L. Jr., Straub M., Wörner M.
and Braun A.M.: J. Phys. Chem., 1998, A. 102, 5542-5550.
Walling C.: Acc. Chem. Res., 1998, 31, 155-159.
MacFaul P.A., Wayner D.D.M. and Ingold K.U.: Acc. Chem. Res., 1998, 31, 159-163.
Pignatello J.J., Liu D. and Huston P.: Environ. Sci. Technol., 1999, 33, 1832-1836.
Gogate P.R. and Pandit A.B.: Adv. Environ. Res., 2004, 8, 501-551.
Deguillaume L, Leriche M. and Chaumerliac N.: Chemosphere, 2005, 60, 718-724.
Haber F. and Willstätter R.: Ber. Dtsch. Chem. Ges., 1931, 64, 2844-2856.
Wardman P. and Candeias L.P.: Radiat. Res., 1996, 145, 523-531.
Hofer T., Method development for analysis of 8-oxodG as a biomarker for oxidative stress. Karolinska
Institutet. 141 57 Huddinge. Stockholm 2001.
Haber F. and Weiss J.: Naturwissenschaften, 1932, 20, 948-950.
Haber F. and Weiss J.: Proc. Roy. Soc. London, 1934, A. 147, 332-351.
Kremer M.L.: Phys. Chem. Chem. Phys., 1999, 1, 3595-3605.
Baxendale J.H., Evans M.G. and Park G.S.: Trans. Faraday Soc., 1946, 42, 155-169.
Barb W.G., Baxendale J.H., George P. and Hargrave K.R.: Trans. Faraday Soc., 1951, 47, 462-500.
Walling C.: Acc. Chem. Res., 1975, 8, 125-131.
Prousek J.: Chem. Listy, 1995, 89, 11-21.
Bray W.C. and Gorin M.H.: J. Am. Chem. Soc., 1932, 54, 2124-2125.
George P.: Disc. Faraday Soc.,1947, 2, 196-205.
Abel E.: Österreich. Chem.-Z., 1948, 49, 79-80.
Koppenol W.H.: Redox Report, 2001, 6, 229-234.
Pestovsky O. and Bakac A.: J. Am. Chem. Soc., 2004, 126, 13757-13764.
Groves J.T.: J. Inorg. Biochem., 2006, 100, 434-447.
Halliwell B.: Plant Physiol., 2006, 141, 312-322.
Bogdanova A.Y. and Nikinmaa M.: J. Gen. Physiol., 2001, 117, 181-190.
Henle E.S. and Linn S.: J. Biol. Chem., 1997, 272(31), 19095-19098.
Mwebi N.O.: Fenton & Fenton-like reactions: the nature of oxidizing intermediates involved. Faculty of
the Graduate School of the University of Maryland, Maryland 2005.
Czapski G.: Meth. Enzymol., 1984, 105, 209-215.
Aruoma O.I.: J. Am. Oil Chem. Soc., 1998, 75, 199-212.
358
[46] Caillet S., Yu H., Lessard S., Lamoureux G., Ajdukovic D. and Lacroix M.: Food Chem., 2007, 100,
542-552.
[47] Rush J.D. and Koppenol W.H.: J. Biol. Chem., 1986, 261 (15), 6730-6733.
[48] Wink D.A., Nims R.W., Saavedra J.E., Utermahlen W.E., Jr. and Ford P.C.: Proc. Natl. Acad. Sci.,
(USA), 1994, 91, 6604-6608.
[49] Yamazaki I. and Piette L.H.: J. Am. Chem. Soc., 1991, 113, 7588-7593.
[50] Wink D.A., Wink C.B., Nims R.W. and Ford P.C.: Environ. Health Perspect., 1994, 102(Suppl 3),
11-15.
[51] Rahhal S. and Richter H.W.: J. Am. Chem. Soc., 1988, 110, 3126-3133.
[52] Rush J.D. and Koppenol W.H.: J. Am. Chem. Soc., 1988, 110, 4957-4963.
[53] Sutton H.C., Vile G.F. and Winterbourn C.C.: Arch. Biochem. Biophys., 1987, 256, 462-471.
[54] Yamazaki I. and Piette L.H.: J. Biol. Chem., 1990, 265 (23), 13589-13594.
[55] Prousek J.: Pure Appl. Chem., 2007, 79, 2325-2338.
[56] Zepp R.G., Faust B.C. and Hoigne J.: Environ. Sci. Technol., 1992, 26, 313-319.
[57] Moffet J.W. and Zafiriou O.C.: J. Geophys. Res., 1993, 98, 2307-2313.
[58] Zafiriou O. and Bonneau R.: J. Photochem. Photobiol., 1987, 45, 723-727.
[59] Zepp R.G., Hoigne J. and Bader H.: Environ. Sci. Technol., 1987, 21, 443-450.
[60] Faust B.C.: [In:] Aquatic and surface photochemistry, G. Helz, R.G. Zepp and D.G. Crosby (eds.). Lewis
Publishers, Boca Raton 1994, pp. 3-38.
[61] Vaughan P.P. and Blough N.V.: Environ. Sci. Technol., 1998, 32, 2947-2953.
[62] Fukushima M. and Tatsumi K.: Environ. Sci. Technol., 2001, 35, 1771-1778.
[63] Paciolla M.D., Kolla S. and Jansen S.A.: Adv. Environ. Res., 2002, 7, 169-178.
[64] Hug S.J. and Leupin O.: Environ. Sci. Technol., 2003, 37, 2734-2742.
[65] Gonzalez-Davila M., Santana-Casiano J.M. and Millero F.J.: Geochim. Cosmochim. Acta, 2005, 69,
83-93.
[66] Branchaud B.P.: Free radicals as a result of dioxygen metabolism, [In:] Metal ions in biological system.
A. Sigel & H. Sigel (eds.). Mercel & Decker NY (publ.), 36, 79-102 (1999).
[67] Goldstein S. and Meyerstein D.: Acc. Chem. Res., 1999, 32, 547-550.
[68] Sawyer D.T., Sobkowiak A. and Matsushita T.: Acc. Chem. Res., 1996, 29, 409-416.
[69] Gozzo F.: J. Mol. Catal. A: Chem., 2001, 171, 1-22.
[70] Chevallier E., Durand Jolibois R., Meunier N., Carlier P. and Monod A.: Atmos. Environ., 2004, 38,
921-933.
[71] Ensing B., Buda F., Blöchl P.E. and Baerends E.J.: Phys. Chem. Chem. Phys., 2002, 4, 3619-3627.
REAKCJA FENTONA - KONTROWERSJE DOTYCZĄCE CHEMIZMU
Instytut Inżynierii Wody i Ścieków, Politechnika Śląska, Gliwice
Abstrakt: Jest coś intrygującego i jednocześnie fascynującego w tym, że prosta reakcja (jonów Fe2+ z H2O2)
zaobserwowana przez H.J.H. Fentona ponad 110 lat temu jest tak trudna do opisania i pełnego zrozumienia.
Jak dotąd natura utleniających czynników powstających w reakcji Fentona jest przedmiotem ciągłych
kontrowersji, co może być tłumaczone faktem, że reakcja ta występuje powszechnie zarówno w systemach
chemicznych, jak i biologicznych, a także w środowisku przyrodniczym. Jest również paradoksem, że z jednej
strony reakcja Fentona jest z powodzeniem stosowana w ochronie środowiska (np. w oczyszczaniu ścieków
czy remediacji wód gruntowych), a z drugiej strony jest ona czynnikiem powodującym uszkodzenia molekuł
biologicznych, a także odgrywa główną rolę w procesach starzenia się oraz wielu chorobach. Artykuł
przedstawia krótki przegląd dotyczący rodnikowego i nierodnikowego mechanizmu reakcji Fentona
postulowanego w literaturze naukowej, możliwe drogi przemian chemicznych, a także różne punkty widzenia
w tym zakresie.
Słowa kluczowe: reakcja Fentona, odczynnik Fentona, chemizm procesu Fentona, rodnik hydroksylowy, jon
ferrylowy
Vol. 16, No. 3
2009
Klaudiusz GRŰBEL*1, Alicja MACHNICKA* and Jan SUSCHKA*
SCUM HYDRODYNAMIC DISINTEGRATION
FOR WASTEWATER TREATMENT EFFICIENCY UPGRADING
INTENSYFIKACJA OCZYSZCZANIA ŚCIEKÓW
Z WYKORZYSTANIEM HYDRODYNAMICZNEJ DEZINTEGRACJI PIANY
Abstract: The aim of wastewater treatment is mineralization of organic matter and release nutrients removal.
Hydrodynamic disintegration process facility biodegradation of organic matter included in scum biomass of
activated sludge. Hydrodynamic disintegration results in destruction and disruption of the scum
microorganisms as well as increase concentration of organic matter (including proteins and carbohydrates) - in
liquid. In order to have a quantitative measure of the effects of disintegration a coefficient defined as a Degree
of Disintegration (DDM) was introduced. The degree of cell disruption can be measured using biochemical
parameters like the COD or proteins release. Hydrodynamic disintegration can activate the biological
hydrolysis process and therefore, significantly increase the biogas production in anaerobic stabilization. The
additional positive effect improving efficiency of wastewater treatment and capability to developing of
undesirable foam is the disintegration and then inputs to systems in internal or external recirculation with
a part of surplus activated sludge from secondary setting tank.
Keywords: hydrodynamic disintegration, scum, biogas, anaerobic stabilization
Filamentous microorganisms are normally a component of the activated sludge
microflora but they are responsible for scum formation and activated sludge bulking [1].
Foaming is a common problem encountered in many wastewater treatment plants
worldwide, especially in those designed for carbon and nutrients removal [2-7]. The
formed scum can cover the entire surface or at last the surface of the anaerobic
dephosphatation stage and anoxic denitrification stage. Also settling tanks can be
partially or totally covered with the scum. The scum (foam) is considered to be
a burden because of the fact that it is difficult to be removed. Also, the foam eventually
affects adversely the process of anaerobic sludge digestion. Consequently, many
investigators, and treatment plant operators, have given attention to control the foam
forming process.
*
University of Bielsko-Biala, Faculty of Materials and Environment Sciences, Institute of Environmental and
Protection Engineering, ul. Willowa 2, 43-309 Bielsko-Biała
1
360
Klaudiusz Grűbel, Alicja Machnicka and Jan Suschka
Through scum disintegration the structure of the scum is changed, bacteria cells are
opened and the cell content is released. The dissolved components are readily degradable
in a digestion process. Basically, the disintegration process is accomplished by the
application of physical or chemical methods to break down cell walls. Thus, cell walls
are fragmented and intracellular compounds are released. The product can be utilized
both as a substrate in aerobic and anaerobic biological processes. Positive effects were
shown for thermal pretreatment [8-10], addition of enzymes [11, 12], ozonation [13, 14],
chemical solubilization by acidification [15, 16] or alkaline hydrolysis [17], mechanical
disintegration [18-20] and ultrasonic [21-24]. The inclusion of disintegration technology
into the sludge treatment process leads to reduced sludge quantities and markedly
improved sludge quality.
In this investigation hydrodynamic cavitation was used to scum disintegrations.
Disintegrated by hydrodynamic cavitation has a positive effect on the degree and rate of
sludge anaerobic digestion. Hydrodynamic cavitation results in formation of cavities
(bubbles) filled with a vapour-gas mixture inside the flowing liquid, or at the boundary
of constriction devices due to rapid local pressure drop. Subsequently, the pressure
recovers down the constriction (valve or nozzle) and causes cavities to collapse. The
collapse of cavitation bubbles is defined as implosion and the forces associated with
results in mechanical and physico-chemical effects. The physical effects include the
production of shear forces and shock waves, whereas the chemical effects result into the
generation of radicals eg formation of reactive hydrogen atoms and hydroxyl radicals
which recombine to form hydrogen peroxide [25-27].
Anaerobic digestion of sewage sludge can be improved by introducing
a disintegration of scum as a pretreatment process. The disintegration brings a deeper
degradation of organic matter and less amount of output sludge for disposal, a higher
production of biogas and consequently energy yield [28].
The new concept of scum hydrodynamic disintegration described in this paper is
based on the own-constructed cavitation nozzle. The main aim of the article was to
describe the effect of hydrodynamic cavitation on organic matter release and biogas
production. These processes caused intensification of wastewater treatment.
Experimental methods
Foam samples were taken from an EBNR full scale municipal sewage treatment
plant. Mechanical disintegration was executed with a pressure pump (12 bar), which
scum, from a 25 dm3 container, through a 1.2 mm nozzle (Fig. 1). Disintegration was
carried out for 15, 30, 45 and 60 minutes.
COD value was determined for samples before and after each time of disintegration
according to Polska Norma PN-ISO 6060:2006. Procedure given by Lowry was used for
protein determination, whereas the Anthrone method has a high specificity for
carbohydrates. Both methods were according to Gerhardt [29].
Samples of raw activated sludge and with a part of disintegrated scum taken direct
from the full scale treatment plant have been digested in 25 dm3 glass reactors at constant
temperature of 33±2oC. The disintegrated scum constituted 20, 30 and 40% in volume.
During 22 days of digestion the amount of produced biogas was daily monitored.
Scum hydrodynamic disintegration for waste water treatment efficiency upgrading
361
scum
recirculation
chamber
nozzle
pressure pump
Fig. 1. Scheme of installation to scum disintegrations
Organic matter release
Release of organic matter expressed as an increase in soluble COD value is
considered as a tool for measurement of bacteria destruction effects.
Fig. 2. Increase of COD in the scum supernatant after hydrodynamic treatment
362
According to the methodology used, the process of hydrodynamic disintegration was
carried out for 15, 30, 45 and 60 min. Already 30 min of mechanical scum
microorganisms disintegration resulted in COD increase in the filtrate (filter paper) of
609 mg·dm–3 (from 57 to 666 mg·dm–3) (Fig. 2).
Degree of disintegration
For a quantitative measurement of the effects of disintegration - a coefficient defined
as a Degree of Disintegration (DD) was introduced. In this case, the degree of sludge
disintegration was determined according to that given by Müller [18] - reading as
follows:
DDM = [(COD1 – COD2) / (COD3 – COD2)] · 100%
(1)
where: DDM - degree of disintegration, COD1 is the COD of the liquide phase of the
disintegrated sample, COD2 is the COD of the original sample, and COD3 is the value
after chemical disintegration.
In accordance with equation (1) - an increase of degree of disintegration was
noticed. The results are presented in Figure 3.
Fig. 3. Change of DDM with time of disintegration
Within the range of explored time, between 15 min and 60 min, the degree of
disintegration increased most rapidly in the first 30 min. The achieved degree of scum
disintegration was about 47%. The efficiency of scum disintegration increased further for
prolonged time (Fig. 3).
Release of proteins and carbohydrates
Increase of the DDM was attributed to break-up of microbial cells leading to the
release of intracellular materials. Moreover, destruction microorganisms of scum in the
363
process of hydrodynamic disintegration resulted in protein and carbohydrate release into
the aqueous phase (Fig. 4).
Fig. 4. Release of proteins and carbohydrates with increase of degree of scum disintegration
As shown in Figure 4, the predominant component released to the liquid was
protein. The release of protein was the fastest during the first 30 min (DDM was 47%). In
this case, concentration of protein increase to 250 mg·dm–3, and then became slower with
the increase of disintegration time. It was observed that carbohydrate concentration
increased as the time of disintegration increased. As in the case of protein, the
concentration of carbohydrate increased in the first 30 min of disintegration. However,
the carbohydrates release was lower.
On basis of obtained results - it was affirmed that amount of proteins released in the
process of disintegration can be adopted as a suitable parameter for assessing the rate of
disintegration.
As in the case of released organic matter - expressed as COD value, an attempt was
made to determinate the degree of disintegration based on the recorded changes in
protein concentration. In this method, the degree of disintegration is based on the protein
concentration in the liquid phase of the sludge of the original and disintegrated sample.
The sludge sample after chemical disintegration was used as a blank sample. Chemical
protein release was achieved by means of NaOH. The degree of activated sludge
disintegration was calculated as follows (2) and shows in Figure 5:
DDP = (P1 – P2 / P3 – P2) · 100(%)
(2)
where: DDP - degree of disintegration, P1 is the concentration of protein in the liquid
phase of the disintegrated sample, P2 is the concentration of protein in the original
sample, and P3 is the value after chemical disintegration. Chemical disintegration of
sample was carried out according to determination of total protein concentration given by
Gerhardt [29].
364
Fig. 5. Change of DDP with time of disintegration
Practical implementation
Hydrodynamic disintegration accelerates the biological degradation of sludge. The
released cell liquid contains components, which can be easily assimilated. The released
organic substances (expressed here as COD or as protein and carbohydrate
concentration) as the effect of scum disintegration, leads to a substantial increase of
biogas production in the process of anaerobic sludge digestion (Fig. 6).
Fig. 6. Production of biogas
365
Significantly higher amounts of biogas were produced in the fermenters fed with
disintegrated scum. The production of biogas increased in samples with addition scum
after 30 minutes hydrodynamic disintegration, as compared with sample of activated
sludge. The organic matter transferred by hydrodynamic treatment from the scum solids
into the liquid phase was readily biodegradable. The break-up of cells walls of the
bacteria limits the degradation process. By applying hydrodynamic disruption, the lysis
of cells occurs in minutes rather than days. The intracellular and extracellular
components are set free and are immediately available for biological degradation which
leads to an acceleration of the anaerobic process.
Conclusions
1.
2.
3.
4.
The hydrodynamic disintegration of scum destroys and disrupts the scum
microorganisms. As a result of disintegration, organic matter was transferred from
the sludge solids into the liquid phase (expressed as COD). A higher increase of
COD was observed after 30 minutes. The value of COD increase in the filtrate (filter
paper) of 609 mg·dm–3 (from 57 to 666 mg·dm–3).
The degree of disintegration increased most rapidly in the first 30 min. The achieved
degree scum disintegration was about 47%.
As a result of scum disintegration, organic matter was transferred from the scum
solids into the liquid phase (expressed as COD). The disruption of cell
microorganisms structure leads to an increase of polymers: proteins and
carbohydrates. As a result, hydrodynamic disintegration causes an enhance
biodegradability.
Addition of disintegrated scum to the fermentation process caused increase in biogas
production. Significantly higher production of biogas was observed in the fermenters
fed with disrupted of microorganisms scum in comparing with the fermenter fed with
raw activated sludge after 22 days anaerobic process. The production of biogas
increase with addition of scum disintegrated.
References
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
Soddell J.A. and Seviour R.J.: Microbiology of foaming in activated sludge plants, J. Appl. Bacteriol.,
1990, 69, 145-176.
Rossetti S., Tomei M.C., Nielsen P.H., and Tandoi V.: “Microthrix parvicella”, a filamentous
bacterium causing bulking and foaming in activated sludge systems: a review of current knowledge.
FEMS Microbiol. Rev., 2005, 29, 49-64.
Madoni P., Davoli D. and Gibin G.: Survey of filamentous microorganisms from bulking and foaming
activated-sludge plants in Italy. Water Res., 2000, 34, 1767-1772.
Blackbeard J.R., Gabb D.M.D., Ekama G.A. and Marais G.V.R.: Identification of filamentous
organisms in nutrient removal activated sludge plants in South Africa. Water SA, 1988, 14, 29-33.
Hiraoka M. and Tsumura K.: Suppression of actinomycete scum production a case study at Senboku
wastewater treatment plant, Japan. Water Sci. Technol., 1984, 16, 83-90.
Hiraoka M., Takedan-Sakai S. and Yasuda A.: Highly efficient anaerobic digestion with thermal
pretreatment. Water Sci. Technol., 1984, 17, 529-539.
Seviour E.M., Williams C., DeGrey B., Soddell J.A., Seviour R.J. and Lindrea K.C.: Studies on
filamentous bacteria from Australian activated sludge plants. Water Res., 1994, 28, 2335-2342.
Miah M. S., Tada Ch., Yang Y. and Sawayama S.: Aerobic thermophilic bacteria enhance biogas
production. J. Mater. Cycles Waste Manage., 2005, 7, 48-54.
366
[9]
Tanaka S., Kobayashi T., Kamiyama K.-I. and Signey Bildan M.L.N.: Effects of thermochemical
pretreatment on the anaerobic digestion of waste activated sludge. Water Sci. Technol., 1997, 35,
209-215.
Li Y.Y. and Noike T.: Upgrading of anaerobic digestion of waste activated sludge by thermal
pretreatment. Water Sci. Technol., 1992, 26, 857-866.
Roman H.J., Burgess J.E. and Pletschke B.I.: Enzyme treatment to decrease solids and improve
digestion of primary sewage sludge. African J. Biotechnol., 2006, 5, 963-967.
Knapp R.T., Daily J.W. and Hammitt F.G.: Cavitation. McGraw-Hill, New York 1970.
Weemaes M., Grootaerd H., Simoens F. and Verstraete W.: Anaerobic digestion of ozonized biosolids.
Water Res., 2000, 34, 2330-2336.
Yasui H. and Shibata M.: An innovative approach to reduce excess sludge production in the activated
sludge process. Water Sci. Technol., 1994, 30, 11-20.
Gaudy A.F., Yang P.Y. and Obayashi A.W.: Studies on the total oxidation of activated sludge with and
without hydrolytic pre-treatment. J. Water Pollut. Control Federation, 1971, 43, 40-54.
Woodard S.E. and Wukasch R.F.: A hydrolysis/thickening/filtration process for the treatment of waste
activated sludge. Water Sci. Technol., 1994, 30, 29-38.
Mukherjee S.R. and Levine A.D.: Chemical solubilization of particulate organics as a pretreatment
approach. Water Sci. Technol., 1992, 26, 2289-2292
Müller J.: Mechanical disintegration of sewage sludge (Mechanischer Klärschlammaufschluß).
Schriftenereihe ”Berichte aus der Verfahrenstechnik” der Fakultät für Maschinenbau und Elektrotechnik
der Universität Braunschweig. Shaker Verlag, Aachen 1996.
Müller J.: Disintegration as key-stop in sewage sludge treatment, Water Sci. Technol., 2000, 41,
123-139.
Kopp J., Müller J., Dichtl N. and Schwedes J.: Anaerobic digestion and dewatering characteristics of
mechanically disintegrated excess sludge. Water Sci. Technol., 1997, 36, 129-136.
Antoniadis A., Poulios I., Nikolakaki E. and Mantzavinos D.: Sonochemical disinfection of municipal
wastewater. J. Hazard. Mater., 2007, 146, 492-495.
Wang F., Lu S. and Ji M.: Components of released liquid from ultrasonic waste activated sludge
disintegration. Ultrasonics Sonochem., 2006, 13, 334-338.
Zhang G., Zhang P., Yang J. and Chena Y.: Ultrasonic reduction of excess sludge from the activated
sludge system. J. Hazard. Mater., 2007, 145, 515-519.
Zhang P., Zhang G. and Wang W.: Ultrasonic treatment of biological sludge: Floc disintegration, cell
lysis and inactivation. Bioresource Technol., 2007, 98, 207-210.
Vichare N.P., Gogate P.R. and Pandit A.B.: Optimization of hydrodynamic cavitation using a model
reaction, Chem. Eng. Technol., 2000, 23, 683-690.
Senthilkumar P., Sivakumar M. and Pandit A.B.: Experimental quantification of chemical effects of
hydrodynamic cavitation. Chem. Eng. Sci., 2000, 55, 1633-1639.
Senthilkumar P. and Pandit A.B.: Modelling hydrodynamic cavitation. Chem. Eng. Technol., 1999, 22,
1017-1027.
Tiehm A., Nikel K., Zellhorn M. and Neis U.: Ultrasonic waste activated sludge disintegration for
improving anaerobic stabilization. Water Res., 2001, 35, 2003-2009.
Gerhardt P., Murray R.G.E., Wood W.A. and Krieg N.R.: Methods for General and Molecular
Bacteriology. ASM 2005, Wahington DC.
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
[28]
[29]
INTENSYFIKACJA OCZYSZCZANIA ŚCIEKÓW Z WYKORZYSTANIEM
HYDRODYNAMICZNEJ DEZINTEGRACJI PIANY
Instytut Ochrony i Inżynierii Środowiska, Wydział Nauk o Materiałach i Środowisku
Akademia Techniczno-Humanistyczna
Abstrakt: Podstawowym celem oczyszczania ścieków jest mineralizacja związków organicznych i usuwanie
substancji biogennych. Jedną z możliwości ułatwienia biodegradacji substratów organicznych obecnych
w biomasie piany osadu czynnego jest proces hydrodynamicznej kawitacji. Hydrodynamiczna dezintegracja
piany powstającej w komorach osadu czynnego skutkuje rozdrobnieniem i destrukcją struktury
mikroorganizmów, a tym samym wzrostem stężenia materii organicznej - w tym białek i polisacharydów -
367
w cieczy. Określenie skuteczności i ilości uwolnionej substancji organicznej w procesie dezintegracji można
wyrazić za pomocą tzw. stopnia dezintegracji określanego na podstawie zmian wartości ChZT (DDM) lub
stężenia uwolnionych białek (DDP). Hydrodynamiczna dezintegracja mikroorganizmów umożliwia proces
biologicznej hydrolizy, przez co znacząco wpływa na wzrost produkcji biogazu w procesie fermentacji.
Dodatkowym pozytywnym efektem poprawiającym skuteczność oczyszczania ścieków i możliwość
zagospodarowania niepożądanej piany jest jej dezintegracja, a następnie wprowadzenia do systemy
oczyszczania ścieków w procesie recyrkulacji wewnętrznej lub zewnętrznej wraz z częścią osadu z osadnika
wtórnego.
Słowa kluczowe: hydrodynamiczna dezintegracja, piana, biogaz, beztlenowa stabilizacja
Vol. 16, No. 3
2009
Grzegorz ŁAGÓD*1, Mariola CHOMCZYŃSKA*, Agnieszka MONTUSIEWICZ*
Jacek MALICKI* and Andrzej BIEGANOWSKI**
PROPOSAL OF MEASUREMENT AND VISUALIZATION
METHODS FOR DOMINANCE STRUCTURES
IN THE SAPROBE COMMUNITIES
PROPOZYCJA POMIARU PODOBIEŃSTWA STRUKTURY DOMINACJI
ZBIOROWISK SAPROBÓW I WIZUALNEJ PREZENTACJI
ZMIAN TEJ CHARAKTERYSTYKI
Abstract: A large taxonomic diversification of saprobes causes difficulties in practical use of the saprobic
system for biomonitoring purpose. In such a case taxonomic levels higher than species level became more
popular. Methods based on biocenotic structure can be also used in bioindication. It is known that application
of the Shannon biodiversity index based not only on numbers and abundances of species but also on numbers
and abundances of easily identified morphological-functional groups gives the same information as saprobe
measurements. Moreover, the other structural indices together with the Shannon index can be used to obtain
more complete characteristics of saprobe communities. It enables more precise interpretation of biomonitoring
results based on dominance structure of organism groups settled at the examined object. The obtained results
of the quantitatve nature can be compared with a chosen accuracy, however they are difficult to be perceived.
The aim of the present work is calculating a similarity of dominance structures characterizing saprobe
communities as well as presenting modified methods for visualisation of these structure changes.
Keywords: saprobes, activated sludge, biofilm, bioindication, similarity coefficient, dominance structure,
dentrite, physical-chemical sewage parameters
Urban sewer systems are settled by saprobe communities which form biofilm on the
walls of the sewers and backbones alike to an activated sludge. These organisms cause
decrease in pollutant load in sewage before they reach a wastewater treatment plant [1-4].
Species structure of mentioned communities is similar to activated sludge or biofilm in
the bioreactor of sewage treatment plant. It is also similar to the structure of organism
communities of saprobic zones specified for water bodies. The sewage parameters can be
*
Faculty of Environmental Engineering, Lublin University of Technology, ul. Nadbystrzycka 40B,
20-618 Lublin, Poland, tel. 081 538 43 22
**
Institute of Agrophysics, Polish Academy of Sciences, ul. Doświadczalna 4, 20-290 Lublin, Poland
1
370
G. Łagód, M. Chomczyńska, A. Montusiewicz, J. Malicki and A. Bieganowski
established based on the presence of microorganisms from the saprobic system living in
the sewerage and using sewage as a source of nourishment [5-7].
A large taxonomic diversification of saprobes causes difficulties in the practical use
of saprobic system. Thus, taxonomic levels higher than species level became more
popular for biomonitoring purposes. Methods based on biocenotic structure (organism
distribution among species) can be also used in bioindication [8]. It has been shown that
application of the Shannon biodiversity index gives the same information as saprobe
measurements. It is known that this information can be obtained using index calculation
based not only on numbers and abundances of species but also on numbers and
abundances of easily identified morphological-functional groups [5, 9].
The Shannon index H is calculated according to the equation [10]:
S
H =−
∑Π
i
log 2 Π i
i =1
where: S - species (or morphological-functional group) richness, number of species (or
number of morphological-functional groups) and Πi - relative abundance of the “i-th”
species (or the “i-th” morphological-functional group).
Relative abundances, necessary for the calculation of the Shannon index and derived
indices, are determined on the basis of the following equation [10]:
Πi =
ni
nT
where: ni - number of individuals in the ”i-th” species or in “i-th” morphologicalfunctional group; and nT - total number of individuals in a sample.
Relative abundances take values in the range 0-1; after multiplication by 100 they are
expressed as percentages.
Besides the Shannon index other structural indices can be used for bioindication
purposes. Among them species richness, maximal value of the Shannon index,
MacArthurs’ index and proportionality index are used most frequently.
Species richness ∆Sr, or taxon richness S is determined by simply summing all taxa
belonging to a community [10]. Maximum value of the Shannon index Hmax [11, 12] is
calculated using the following formula:
H max = log 2 S
where S - number of species (or morphological-functional groups).
Evenness index V [11, 12] is calculated as:
V=
H
H max
where: H - observed value of the Shannon index for the studied saprobe community and
Hmax - value of the Shannon index when all taxa are equally abundant in the community.
Proposal of measurement and visualization methods for dominance structures in the saprobe …
371
MacArthur’s index E [13] is calculated on the basis of the following equation:
E = 2H
where 2 - the base of the logarithm.
The value of MacArthur’s index, E is the taxon richness of a community for which the
observed value of H equals Hmax. Proportionality index P [14, 15] is calculated using the
formula:
P = E/S 100
where: E - value of MacArthur’s index and S - species richness or morphologicalfunctional group richness for studied community.
The index P can express “shortage in the taxa number” in the investigated community.
The studies may also be based on the other biodiversity indices eg Simpson index [16]
determining the probability that two individuals “allotted” in the single trial belong to the
same species. The estimator of this index is as follows:
S
D =1−
ni ( ni − 1)
T ( nT − 1)
∑n
S =1
The mentioned indices give more complete characteristics of saprobe communities,
in so doing they permit for more precise interpretation of biomonitoring results based on
dominance structure of organism groups settled at an examined object. The obtained
results of quantity nature can be compared with a chosen accuracy, however they are
difficult to be perceived. The graphical methods for comparison of the dominance
structure for saprobe communities have been presented in our previous publications as
suitable visualisation tools [7, 9]. However, these methods have some inconveniences
which implicate the necessity of their modifications. Thus, the aim of this paper is to
calculate a similarity of dominance structures characterizing saprobe communities as well
as present modified method for visualisation of these structure changes.
Material and methods
The material used for our previous and present study came from Klimowicz’s
elaboration [17]. The author presented species composition and individual abundances
for communities of activated sludge in specified wastewater classes (characterized by
biological oxygen demand ranges: 0÷10, 11÷20, 21÷30 and > 30 g O2 m–3). On the basis
of the Klimowicz’s data set relative abundances of distinguished morphologicalfunctional groups were calculated (Πi). The relative abundances mentioned above were
multiplicated by 100 to obtain percent fractions. The percent fractions were used in
calculations of Renkonen’s similarity coefficients for the compared communities of
activated sludge [18]. The obtained values of Renkonen’s coefficients were sorted using
Czekanowski’s diagram [19]. Both Czekanowski’s and Renkonen’s methods are used in
phytosociology to sort results of the floral inventory and to specify plant associations.
There are also possible, different than Renkonnen measures of studied communities
similarity. For example - the factor of similarity [16, 18-21]:
372
Jaccard and Steinhaus:
P=
w
⋅100
a+b+ w
P=
w
⋅100
a+b−w
P=
100  w w 
⋅ + 
2 a b
Marczewski and Steinhaus:
Kulczyński:
Sorensen:
P=
2w
⋅ 100
a+b
William and Mantford:
P=
2w
⋅ 100
2ab − (a + b) w
where: P - obtained species similarity [%] of two compared communities, a - number of
species in the first community, b - number of species in the second community,
w - number of common species appearing in both studied communities.
The calculations may be also conducted in the more precise way - after calculation
of Πi = ni/nT, for every species in every community, where a and b are equal to 1 and a is
a sum of lower values of Πi I i Πi II (eg species 1 in agglomeration I Π1 = 0.2, species 1
in community II Π1 = 0.1, so the value of 0.1 is selected to the calculations).
The percent fractions of morphological-functional groups were graphically
visualized using “radar” plots also called “AMOEBAs” since the publication of the Ten
Brink’s paper [22]. During preparation of “AMOEBAs” plots original fractions and their
natural logarithms were marked.
Results
The study results are presented in Figures 1 and 2. It can be seen that changes in
pollution level influence dominance structure of the described communities (Fig. 1). The
changes in dominance structure are clearly visualized by radar plots with original
fractions (grey colour). In the community I (BOD5 range: 0÷10 g O2 m–3) attached
ciliates are dominants and rotifers are subdominants (Fig. 1a). The community II (BOD5
range: 11÷20 g O2 m–3) is characterized by attached ciliates as dominants and swimming
ciliates as subdominants (Fig. 1b). In the community III (BOD5 range: 21÷30 g O2 m–3)
attached ciliates also play role of dominants and new subdominants as flagellates appear
(Fig. 1c). Finally, in the community IV (BOD5 range: >30 g O2 m–3) the dominance of
flagellates is observed and amoebas become subdominants (Fig. 1d). The described
changes of dominance structure are not presented so clearly using logarithms of fractions.
373
However, their application enables the extremely low fractions of morphologicalfunctional groups to be observed (Fig. 1a and 1b - black colour).
Fig. 1. Relative abundances of morphological-functional groups in specified classes of purified
sewage. Explanation: 1 - swimming ciliates, 2 - attached ciliates, 3 - crawling ciliates,
4 - rotifers, 5 - flagellates, 6 - amoebaes, 7 - nematodes, 8 - oligochaetes, 9 - gastrotriches,
10 - arachnids, 11 - tardigrades, 12 - copepods, 13 - cladocers, 14 - turbellarians
Fig. 2. Coefficients of taxa similarity for specified classes of purified sewage
374
In studied material two different groups of an activated sludge communities can be
distinguished (Fig. 2a and 2b). They are present in wastewater classes with BOD5 range:
0÷20 g O2 m–3 and > 21 g O2 m–3, respectively. Parallely, the community present in class
with BOD5 range: 21÷30 g O2 m–3 is similar to those from classes characterized by BOD5
range: 11÷20 and >30 g O2 m–3 to the same degree (about 70%).
Beside Czekanowski’s diagram, the other manners for visualization of studied
communities’ similarity are also possible [16, 21]. Mentioned manners (dendrite and
dendrogram) are presented in this paper with use of results obtained with Renkonnen
method. A reason for this is that calculation of Renkonnen’s coefficient is the most
convenient as compared with other methods for determination of taxon similarity
coefficient (Jaccard and Steinhaus’es coefficient, Marczewski and Steinhaus’es
coefficient, Kulczyński coefficient, Sorensen’s coefficient, William and Mantford’s
coefficient [16, 19-21]).
A dendrite of mutual similarities is obtained by selection of the highest similarity
coefficients from Table b (Fig. 2). The community I has one high coefficient and is
similar to the community II in 73.45%. The community II has two high values of
similarity coefficients and is also in 69.14% similar to community III, which is
characterised by the 70.90% similarity to the community IV. The distances inside the
dendrite among the communities are: 26.55% between community I and II (because
100 – 73.45 = 26.55, for the 100% similarity the distance would be equal to 0), 30.86%
between community II and III and 29.10% between community III and IV - Figure 3.
I
26.55
II
30.86
III
29.10
IV
Fig. 3. Distances between communities I, II, III and IV presented in a form of dendrite
Obviously, each of compared communities may have more than 2 high similarity
coefficients. In this case, a dendrite becomes branched. It seems, that a dendrite does not
give a lot of information but in the case of higher number of the studied communities,
a dendrite construction makes easier on arrangement of Czekanowski’s diagram.
The highest available level of information may be obtained from a dendrogram. It is
created by the gradual connection of compared communities, but joining subsequent
communities requires the calculation of mean coefficient on all its values already existing
in a dendrogram. The dendrogram presented in Figure 4 may be constructed basing on
data presented in Table b (Fig. 2). The sum of species similarity coefficient’s equals to:
73.45 + 70.90 + 57.085 = 201.435 (Fig. 4). At assumption of different dimensions
(Fig. 5) the sums are equal to: 73.45 + 65.035 + 56.39 = 194.875 and
70.90 + 60.64 + 60.17 = 191.71. In such cases the sums appear to be lower, thus array of
communities according to taxon similarity is worse.
The dendrogram helps to observe the dependence similar to the one visible in Figure
1 where communities a and b are more similar one to another than to communities c and
d. The latter show the mutual similarity especially when the values of ln Πi are presented.
90%
II
I
375
IV
III
80%
73.45
70.90
70%
60%
57.085
50%
Fig. 4. Distances between communities presented in a form of dendrogram
80%
II
I
III
IV
II
I
IV
III
73.45
70.90
70%
65.035
60.17
60%
60.64
56.39
50%
Fig. 5. Distances between communities presented in a form of dendrograms with different
construction
Conclusions
1.
2.
3.
4.
5.
6.
Changes in wastewater pollution level cause differences in dominance structure of
saprobe communities.
Percent fractions of taxa calculated for biomonitoring purposes can be also used for
determination of similarity coefficients between compared communities.
Saprobe fractions below 1% are clearly visualized as logarithm values.
Changes in dominance structure are the best observed using radar plots called
“AMOEBAs”.
Czekanowski’s diagrams can be used for sorting of communities considering their
taxa similarity.
The satisfactory diversification may be obtained when dendrogram is used to the
similarity visualization.
Acknowledgements
This work was supported by the Ministry of Science and Higher Education of
Poland, No. 4949/B/T02/2008/34
376
References
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
Łagód G., Sobczuk H. and Suchorab Z.: Kolektory kanalizacyjne jako część kompleksowego układu
oczyszczania ścieków. Monografie Komitetu Inżynierii Środowiska PAN. II Kongres Inżynierii
Środowiska w Lublinie, 2005, 32, 835-843.
Hvitved-Jacobsen T., Vollertsen J. and Nielsen P.H.: Koncepcja procesu i modelu dla przemian
mikrobiologicznych zachodzących w ściekach w kanalizacjach grawitacyjnych. Materiały
Międzynarodowej Konferencji Naukowo-Technicznej nt. Usuwanie związków biogennych ze ścieków.
Kraków 1997, 12, 227-239.
Hvitved-Jacobsen T.: Sewer Processes. Microbial and Chemical Process Engineering of Sewer Networks.
CRC PRESS, Boca Raton, London, New York, Washington 2002.
Huisman J.L.: Transport and transformation process in combined sewers. IHW Shriftenfreihe, 2001, 10,
1-180.
Łagód G., Malicki J., Montusiewicz A. and Chomczyńska M.: Wykorzystanie mikrofauny saprobiontów
do bioindykacji jakości ścieków w systemach kanalizacyjnych. Arch. Environ. Protect./ Arch. Ochr.
Środow., 2004, 30(3), 3-12.
Łagód G., Sobczuk H. and Suchorab Z.: Application of a saprobiontic microorganisms community
analysis in the calibration of a model description of sewage self-purification in sewer systems. Ecol.
Chem. Eng., 2006, 13(3-4), 265-275.
Łagód G., Chomczyńska M., Malicki J. and Montusiewicz A.: Quantitative methods of descritption,
estimation and comparison of microorganism communities in urban sewer systems. Ecol. Chem. Eng.,
2006, 13(3-4), 255-263.
Gorzel M. and Kornijów R.: Biologiczne metody oceny jakości wód rzecznych. Kosmos, 2004, 53(2),
183-191.
Montusiewicz A., Malicki J., Łagód G. and Chomczyńska M.: Estimating the efficiency of wastewater
treatment in activated sludge systems by biomonitoring. Environmental Engineering, Taylor & Francis
Group, London 2007, 47-54.
Gove I.H., Patil G.P., Swindel B.F. and Taille C.: Ecological diversity and forest management.
Handbook of Statistic 12, Elsevier Science B.V., North-Holland, Amsterdam, London, New York, Tokyo
1994, 409-462.
Hulbert S.H.: The nonconcept of species diversity: a critique and alternative parameters. Ecology,
1971, 48, 577-586.
Magurran A.: Ecological diversity and its measurements. Croom Helm, London, Sydney 1988.
MacArthur R.H.: Patterns of diversity. Biol. Rev., 1965, 40, 510-533.
Łagód G., Malicki J., Chomczyńska M. and Montusiewicz A.: Interpretation of the results of
wastewater quality biomonitoring using saprobes. Environ. Eng. Sci., 2007, 24(7), 873-879.
Chomczyńska M., Montusiewicz A., Malicki J. and Łagód G.: Application of saprobes for bioindication
of wastewater quality. Environ. Eng. Sci., 2009, 26(2), 289-295.
Górny M. and Grum L.: Metody stosowane w zoologii gleby. PWN, Warszawa 1981.
Klimowicz H.: Znaczenie mikrofauny przy oczyszczaniu ścieków osadem czynnym. Zak. Wyd. Instytutu
Kształtowania Środowiska, Warszawa 1983.
Grzyb S.: Obliczanie podobieństwa zdjęć fitosocjologicznych. Zesz. Prob. Podst. Nauk Roln., 1966, 66,
133-136.
Motyka J.: O celach i metodach badań geobotanicznych. Ann. UMCS, sec. C suppl. 1947, (1), 1-168.
Romaniszyn W.: Uwagi krytyczne o definicji Sorensena i metodzie Renkonnena obliczania
współczynników podobieństwa wzorów. Wiad. Ekol., 1972, 18, 375-380.
Kreshaw K. A.: Ilościowa i dynamiczna ekologia roślin. PWN, Warszawa 1978.
Ten Brink B.J.E., Hosper S.H. and Colijn F.: A quantitative method for description and assessment of
ecosystems: the AMOEBA - approach. Marine Pollut. Bull., 1991, 23, 265-270.
377
PROPOZYCJA POMIARU PODOBIEŃSTWA STRUKTURY DOMINACJI
ZBIOROWISK SAPROBÓW I WIZUALNEJ PREZENTACJI
ZMIAN TEJ CHARAKTERYSTYKI
Wydział Inżynierii Środowiska, Politechnika Lubelska
Instytut Agrofizyki PAN
Abstrakt: Zróżnicowanie taksonomiczne systemu saprobów wiąże się z trudnościami w jego zastosowaniu do
celów biomonitoringu. Dlatego też wprowadzenie do bioindykacji jednostek taksonomicznych wyższych rangą
od gatunku oraz metod opartych na strukturze biocenotycznej staje się powszechne. Zastosowanie indeksu
bioróżnorodności Shannona, bazującego nie tylko na liczbie i ilościowości gatunków, lecz również na liczbie
i liczebności łatwo identyfikowalnych grup morfologiczno-funkcjonalnych, jest tak samo przydatnym źródłem
informacji jak pomiary saprobowości. W celu otrzymania pełniejszej charakterystyki badanego obiektu obok
indeksu Shannona stosowane są także inne indeksy struktury biocenotycznej. Użycie tych indeksów
umożliwia bardziej precyzyjną interpretację wyników biomonitoringu uwzględniającego strukturę dominacji.
Ze względu na ilościowy charakter danych wyniki mogą być porównywane z dowolną dokładnością, jednakże
są mało czytelne w odbiorze. Celem prezentowanej pracy jest wyznaczenie podobieństwa struktury dominacji
zbiorowisk saprobów i przedstawienie metod wizualizacji zmian badanych struktur.
Słowa kluczowe: system saprobów, osad czynny, błona biologiczna, bioindykacja, współczynniki
podobieństwa, struktury dominacji, dendryty, parametry ścieków
Vol. 16, No. 3
2009
Ewa RADZIEMSKA*1, Piotr OSTROWSKI* and Tomasz SERAMAK**
CHEMICAL TREATMENT OF CRYSTALLINE SILICON SOLAR
CELLS AS A MAIN STAGE OF PV MODULES RECYCLING
OBRÓBKA CHEMICZNA KRZEMOWYCH OGNIW SŁONECZNYCH
JAKO NAJWAŻNIEJSZY ETAP W RECYKLINGU
MODUŁÓW FOTOWOLTAICZNYCH
Abstract: In recent years, photovoltaic systems have gained worldwide recognition and popularity as
a environmentally friendly way of solving energetic problems. However, a problem of utilizing worn out
photovoltaic systems, amount of which will rapidly increase in the future, is yet to be solved. Establishing
a technology of recycling and reusing obsolete photovoltaic panels is a necessity. Photovoltaic modules of
crystalline silicon solar cells are made of the following elements, in order of increasing mass: glass, aluminum
frame, EVA copolymer transparent hermetizing layer, photovoltaic cells, installation box, Tedlar protective
foil and assembly bolts. From an economic point of view, taking into account the price and supply level, pure
silicon, which can be recycled from PV cells, is the most valuable building material used. A way of utilizing
obsolete and out-of-use photovoltaic silicon cells has been presented. Because of a high quality requirement
for silicon obtained, chemical processing is the most important stage of recycling process. Conditions for
chemical treatment need to be precisely adjusted in order to achieve the required purity level of recycled
silicon. For crystalline silicon based PV systems, a series of etching processes has been performed on, in order:
electric connectors, ARC and n-p junction layer. The compositions of etching solutions were individually
adjusted for different silicon cell types. Efforts were taken to formulate a universal etching solution
composition, yet the results showed that a solution modification is required for different types of PV cells.
Keywords: photovoltaic cells, silicon, recycling, solar energy, renewable energy sources
In recent years, photovoltaic systems have gained worldwide recognition and
popularity as an environmentally friendly way of solving energetic problems. However,
a problem of utilizing worn out photovoltaic systems, amount of which will rapidly
increase in the future, is yet to be solved. Establishing a technology of recycling and
reusing obsolete photovoltaic panels is a necessity. Photovoltaic modules in crystalline
silicon solar cells are made of the following elements, in order of increasing mass: glass,
aluminum frame, EVA copolymer transparent hermetizing layer, photovoltaic cells,
Gdansk University of Technology, * Chemical Faculty, ** Mechanical Faculty, ul. Narutowicza 11/12,
PL-80-233 Gdańsk, Poland, tel. +48 58 347 18 74
1
380
Ewa Radziemska, Piotr Ostrowski and Tomasz Seramak
installation box, Tedlar protective foil and assembly bolts. From an economic point of
view, taking into account the price and supply level, pure silicon, which can be recycled
from PV cells, is the most valuable building material used. Several solar cells from
different manufacturers were tested (Tab. 1).
Table 1
Tested silicon solar cells from different manufacturers
Cell Fragment
Cell Type
Thickness
[µm]
Size
axb
[mm]
1
Monocrystalline
345
125x125
2
Monocrystalline
295
125x125
3
Monocrystalline
545
125x125
4
Monocrystalline
235
125x125
5
Monocrystalline
340
125x125
6
Monocrystalline
275
125x125
7
Polycrystalline
356
125x125
8
Polycrystalline
395
125x125
9
Polycrystalline
250
125x125
10
Polycrystalline
300
105x105
Sample
Front
Back
Chemical treatment of crystalline silicon solar cells as a main stage of PV modules recycling
381
Crystalline silicon photovoltaic cells are produced as plates of 200÷500 µm
thickness and in sizes: 100 x 100 mm2, 125 x 125 mm2 or 150 x 150 mm2. On the frontal
surface of these plates, through the process of atomic diffusion of phosphorus, an n-p
semiconductor layer is created, on which an anti-reflective coating (ARC) is applied. In
the next phase of the production process, two electrodes made of aluminum and/or silver
paste are created on the plate front and back side [1].
Recycling of crystalline silicon photovoltaic cells and modules
The PV module production process involves laminating single cells (after the
creation of n-p connector layer) and mounting in aluminum frames. That is why the
recycling process requires disassembling the modules according to the flow chart shown
in Figure 1.
PV Module
Muffle furnace
temp. >500oC
Module components separation
Al, Cu, Steel
PV Cells
Glass
Recycling
Metal
Recycling
Hazardous
gas emission
Glass
Chemical
Processes
PV Cells
New PV Cells
Production
Silicon
Plates
Cell Quality
Control
Use of silicon powder as
a technological
component
Silicon
Silicon
Powder
Production
Fig. 1. Thermal and chemical processes involved in crystalline cell and module recycling
A thermal process allowing fast, simple and economically efficient module part
disassembling is the first stage of PV module recycling. Firstly, the EVA-laminated cells
(EVA - Ethylene-Vinyl Acetate copolymer) are separated. Tests with chemical EVA
layer removal have been conducted. Results of these tests show that thermal separation
382
is, from an economical and ecological point of view, a more favorable alternative, when
compared with chemical processes, requiring the use of expensive and toxic agents.
The second primary process carried out in PV module recycling is the solar cell
chemical treatment. In order to reacquire the silicon powder or plates, available for use in
new photovoltaic cell production, the removal of metal electrodes, AR coating and n-p
connector layer is required. These operations may be performed through dissolving in
acid or base solutions. Röver’s team research experience on cell texturization with
HF/HNO3/H2O mixture [2] has been acknowledged in this research.
Identification of materials used in silicon PV cell production
Over 90% of all PV cells are silicon-based. Depending on the manufacturing
technology - monocrystalline, polycrystalline and, rarely, amorphous cells are produced.
Several types of PV cells manufactured by different producers and distinguished by
the type of ARC and electric contact material applied, are available on the market.
Frontal electrodes are most commonly made out of silver, while the ones placed on the
cell’s back surface are frequently additionally covered with an aluminum thin layer.
Ag
Ag
Ag
FRONT
BACK
Ag
FRONT
Al
BACK
Anti-reflecting coating
Ag Metallization
n-p junction
Silicon base
Ag/Al Metallization
Fig. 2. Types of materials used in the production of PV cells process
Because of the high value of light reflection index for silicon (33÷54%), a layer
decreasing that value needs to be adopted - that is why the frontal surface of the cell is
covered with an anti-reflection layer, which changes the color of the cell (usually it
becomes blue). AR coatings are made from substances such as:
• Ta2O5 - tantalum pentoxide;
• TiO2 - titanium dioxide;
• SiO - silicon monoxide;
• SiO2 - silicon dioxide;
• Si3N4 - silicon nitride;
• Al2O3 - aluminium oxide;
• ITO (Indium-Tin-Oxide) - Tin doped In2O3.
383
The best results are achieved when multiple coatings are applied, eg a combination
of zinc sulfide (ZnS) and magnesium fluoride (MgF2). Furthermore, trace amounts of
soldering alloys (Sn/Pb) are present.
Recycling of silicon base from spent or damaged PV cells
To allow the recycling of the silicon base from PV cells, a chemical process for
removing different layers from the cell’s surface has been developed (Fig. 3).
PV cell
Si base
CHEMICAL PROCESS
Etching
Rinse
Etching
Rinse
Fig. 3. Recovery of the silicon base from the silicon PV cells
The main problem is choosing the suitable composition and concentration of the
etching solution as well as the optimal temperature range for the chemical reaction.
Base solution etching - removing the Al metallization
In order to remove the Al layer from the cell’s back surface, an aqueous solution of
KOH has been utilized (Fig. 4).
Time [min]
Ag
Al
Ag
KOH
30 %
Si
a
b
T [oC]
Fig. 4. Temperature dependence of the back metallization removing rate and picture of the solar cell
before (a) and after (b) removal of the back metallization with potassium hydroxide
Having in mind that the electric contacts in a majority of produced PV cells are
made of Ag, it is possible to dissolve those elements in nitric acid.
384
Acid etching - removing the AR coating and the n-p junction
Two types of mixtures: H2SiF6/HNO3/CH3COOH and H2SiF6/HNO3/H2O have been
tested for ARC and n-p junction removal.
H2SiF6/HNO3/C2H4O2
Time [s]
Time [min]
H2SiF6/HNO3/H2O
H2SiF6/HNO3/H2O
H2SiF6/HNO3/C2H4O2
T [oC]
T [oC]
Fig. 5. Temperature dependence of the ARC and n-p junction/metallization removing rate
The process of removing the n-p semiconductor junction was carried out until the
dissolution of diffusion layer occurred, with simultaneous control of sheet resistance
Rs [Ω/□] (Ohm by square) with a four-point probe (Fig. 6). The term ohms/square is used
because it gives the resistance in ohms of current passing from one side of a square
region to the opposite side, regardless of the size of the square (on the condition:
d s < 0.5 with reached accuracy of the measurement: ±0.26%).
Resistivity of a semiconducting material, a direct function of dopant concentration,
is one of the basic parameters characterizing silicon PV cell bases, allowing the
determination of:
doping agent’s concentration in the base,
homogeneity of dopant’s surface concentration,
depth of the n-p junction and distribution of dopant concentration in different layers.
UP
S
PB
R
mA
Fig. 6. Measurement of the sheet resistance with the use of four-point probe: UP - voltage meter
circuit, S - four-point probe, PB - tested sample
385
Results of sheet resistance measurements with a four-point probe have been shown
in Figure 7. Based upon these results, the etching processes’ parameters have been set - 2
minutes for the frontal surface in a mixture of acids and 33 minutes for the back surface
in an aqueous KOH solution.
Sheet resistance
Rs [Ω/□]
Back surface
Front surface
Etching time [min]
Fig. 7. Time dependence of the sheet resistance Rs
3
1
2
3
4
5
6
7
8
Front surface
1
2
4
5
7
6
8
Back surface
Fig. 8. View of front and back surfaces after etching in H2SiF6/HNO3/H2O solution - samples 1÷7,
8 - sample before etching
Figure 9 shows a change in etching rate of consecutive layers in the function of
temperature for two mixtures: H2SiF6/HNO3/H2O and H2SiF6/HNO3/CH3COOH.
Etching processes should only be conducted until the removal of desired layers,
whereas it is essential to avoid too great loss of silicon. For the silicon base to be proper
for production of new cells, its thickness must not be too small - a loss of strength may
cause that the base breaks during the series of technological processes carried out on its
surface.
386
Etching rate
[µm/s]
H2SiF6/HNO3/H2O
H2SiF6/HNO3/C2H4O2
T [oC]
Fig. 9. Temperature dependence of etching rate
Results of silicon plate thickness measurements in dependence on temperature of the
applied etching solutions have been shown on Figure 10. Measurements were carried out
with ±1 µm accuracy. For temperatures above 40°C, thickness has decreased below
280 µm because of a rapid increase of the etching rate in that temperature range
(Fig. 10). That is way a precise time control is required for the plate’s immersion in the
etching solution in desired temperature.
Plate thickness
[µm]
Initial thickness
Average thickness after etching
T [oC]
Fig. 10. Temperature dependence of obtained silicon plates thicknesses
Conclusion
A way of utilizing silicon based PV cells from obsolete or damaged PV modules has
been presented. Having in mind the objective of reacquiring high purity materials from
the recycling process, the chemical treatment is the most important stage of this method.
For crystalline silicon-based PV cells, the following chemical treatment processes
have been conducted: removal of metallization, removal of ARC and n-p junction
387
removal through etching. To develop a universal etching solution, modifications of
mixture compositions are required, depending on PV cell’s production technology.
Recycling of the most valuable materials may be applied on the production stage, for
an average 5% of manufactured cells, which do not meet the quality requirements, as
well as for cells spent or damaged cells through improper transport, assembly or use.
References
[1]
Wambach K., Schlenker S., Springer J., Konrad B., Sander K., Despotou E. and Stryi-Hipp G.: PV cycle
- on the way to a sustainable and efficient closed loop system for photovoltaics, 22nd European
Photovoltaic Solar Energy Conference 2007, Milan, Italy.
[2]
Röver, I., Wambach, K., Weinreich, W., Roewer, G. and Bohmhammel K.: Process Controlling of the
Etching System HF/HNO3/H2O, 20th European Photovoltaic Solar Energy Conference 2005, Barcelona,
Spain
OBRÓBKA CHEMICZNA KRZEMOWYCH OGNIW SŁONECZNYCH
JAKO NAJWAŻNIEJSZY ETAP W RECYKLINGU
MODUŁÓW FOTOWOLTAICZNYCH
Politechnika Gdańska, Wydział Chemiczny, Wydział Mechaniczny
Abstrakt: W ostatnich latach systemy fotowoltaiczne stają się niezwykle popularne na całym świecie jako
korzystne dla środowiska rozwiązanie problemów energetycznych. Problem, jak zagospodarować zużyte
elementy systemów fotowoltaicznych, których ilość w przyszłości może być znaczna, nie został do tej pory
rozwiązany. Konieczne jest opracowanie metody recyklingu i ponownego wykorzystania wycofanych z użycia
elementów składowych systemów PV. Moduły fotowoltaiczne wykonane w technologii krystalicznego krzemu
składają się (w kolejności według masy) z następujących elementów: szkła, aluminiowej ramy, przeźroczystej
warstwy hermetyzującej z kopolimeru EVA, ogniw fotowoltaicznych, puszki przyłączeniowej, warstwy folii
ochronnej (Tedlar) i śrub. Z ekonomicznego punktu widzenia oraz z uwagi na jego cenę i ograniczoną podaż
najcenniejszym materiałem, który może być odzyskany z ogniw PV, jest czysty krzem. W artykule
przedstawiono sposób zagospodarowania krzemowych ogniw PV, pochodzących z wycofanych z użycia
modułów. Z punktu widzenia wymaganej wysokiej jakości odzyskiwanych materiałów najważniejszym
etapem proponowanej metody recyklingu są procesy chemiczne. Warunki prowadzenia procesu muszą być
opracowane w taki sposób, aby uzyskać wysoką jakość krzemu z uwzględnieniem jego parametrów
elektrycznych. Dla ogniw wykonanych z krystalicznego krzemu prowadzono następujące po sobie procesy
usuwania poprzez wytrawianie kontaktów elektrycznych, warstwy antyrefleksyjnej oraz złącza n-p. Składy
roztworów trawiących były dostosowywane do różnych rodzajów ogniw krzemowych. Podjęto próby
opracowania składu uniwersalnej kąpieli trawiącej, przy czym konieczne okazało się wprowadzanie
modyfikacji składu roztworu w zależności od rodzaju ogniw PV.
Słowa kluczowe: ogniwa fotowoltaiczne, krzem, recykling, energia słoneczna, odnawialne źródła energii
Vol. 16, No. 3
2009
Dorota KULIKOWSKA*
CHARAKTERYSTYKA ORAZ METODY USUWANIA
ZANIECZYSZCZEŃ ORGANICZNYCH Z ODCIEKÓW
POCHODZĄCYCH Z USTABILIZOWANYCH SKŁADOWISK
ODPADÓW KOMUNALNYCH
CHARACTARIZATION OF ORGANICS AND METHODS TREATMENT
OF LEACHATE FROM STABILIZED MUNICIPAL LANDFILLS
Abstrakt: Przedstawiono charakterystykę zanieczyszczeń organicznych występujących w odciekach
pochodzących ze składowisk odpadów komunalnych z uwzględnieniem związków uznawanych za
niebezpieczne, w tym BTEX, WWA (PAH) i związków chloroorganicznych. Omówiono zależność pomiędzy
wiekiem składowiska a rodzajem i stężeniem zanieczyszczeń organicznych występujących w odciekach.
Dokonano przeglądu piśmiennictwa dotyczącego oczyszczania odcieków pochodzących ze składowisk
ustabilizowanych z zastosowaniem najczęściej wykorzystywanych metod fizykochemicznych,
tj. koagulacji/flokulacji, adsorpcji, pogłębionego utleniania oraz metod membranowych.
Słowa kluczowe: odcieki składowiskowe, związki organiczne, BTEX, WWA, koagulacja/flokulacja,
adsorpcja, pogłębione utlenianie, metody membranowe
Wprowadzenie
Konsekwencją składowania odpadów jest powstawanie odcieków, których
charakterystyczną cechą jest zróżnicowany skład chemiczny zmieniający się w czasie
i zależny od rodzaju deponowanych odpadów i sposobu eksploatacji składowiska.
Powoduje to, że pomimo iż badania nad unieszkodliwianiem odcieków są prowadzone
od wielu lat, to opracowanie wysoko sprawnych metod oczyszczania pozostaje nadal
otwartym problemem.
Wybór metody oczyszczania w dużej mierze zależy od składu chemicznego odcieków
oraz podatności na biodegradację występujących w nich związków organicznych.
W przypadku odcieków ze składowisk młodych polecane są metody biologiczne, a do
oczyszczania odcieków ze składowisk ustabilizowanych, zawierających związki
*
Katedra Biotechnologii w Ochronie Środowiska, Wydział Ochrony Środowiska i Rybactwa, Uniwersytet
Warmińsko-Mazurski w Olsztynie, ul. Słoneczna 45G, 10-907 Olsztyn-Kortowo, tel. 089 523 41 45,
390
Dorota Kulikowska
refrakcyjne, metody fizykochemiczne. W wielu przypadkach duże stężenia
zanieczyszczeń organicznych, w tym refrakcyjnych, powodują, że w celu uzyskania
odpływu o bardzo dobrej jakości konieczne jest stosowanie połączonych metod
fizykochemicznych i biologicznych, czyli tzw. układów wielostopniowych.
W niniejszej pracy dokonano przeglądu literatury, dotyczącej charakterystyki
odcieków, ze szczególnym uwzględnieniem zawartości związków organicznych oraz
przedstawiono najczęściej stosowane metody ich usuwania.
Wpływ wieku składowiska na rodzaj i stężenie
zanieczyszczeń organicznych występujących w odciekach
Podczas deponowania odpadów na składowiskach zachodzą procesy
biochemicznego rozkładu, którym towarzyszą zmiany w składzie jakościowym oraz
ilościowym odcieków. Produktami typowymi dla fazy fermentacji kwaśnej są głównie
lotne kwasy tłuszczowe, alkohole oraz inne małomolekularne związki organiczne, które
są łatwo wymywalne ze złoża składowiska.
Rodzaj i stężenie występujących w odciekach kwasów lotnych może się zmieniać
w zależności od rodzaju składowanych odpadów, wieku składowiska czy warunków jego
eksploatacji [1-3].
Harmsen [3] podaje, że w odciekach pochodzących ze składowiska w fazie kwaśnej
dominowały kwasy octowy i masłowy, a ich stężenia wynosiły odpowiednio
11 000 i 9890 mg/dm3. Zawartość kwasów heksanowego, propionowego
i walerianowego kształtowała się odpowiednio na poziomie: 5770, 3760 i 2510 mg/dm3,
podczas gdy etanolu była znacznie mniejsza - 277 mg/dm3. Z wcześniejszych badań
Burrows i Rowe [1] wynika natomiast, że w odciekach pochodzących z kilkuletniego
składowiska odpadów komunalnych kwas masłowy stanowił 87%, podczas gdy kwasy
walerianowy i propionowy występowały w ilościach stanowiących zaledwie 7 i 6%
całkowitej zawartości kwasów lotnych.
Lotne kwasy tłuszczowe ze względu na małe masy molekularne (poniżej 120 Da)
należą do związków łatwo ulegających biodegradacji [4].
Przemiany związków organicznych znajdujących się w masie składowiska prowadzą
do powstawania związków makromolekularnych, głównie substancji humusowych, które
mogą stanowić nawet 60% rozpuszczalnego węgla organicznego (RWO) [5]. Masy
molekularne substancji humusowych w odciekach wahają się od kilkuset do
kilkudziesięciu tysięcy Da [6], przy czym ich wartość oraz udział procentowy
poszczególnych frakcji zależą od wieku składowiska. Potwierdzają to badania Calace
i współprac. [7], którzy porównali wartości mas molekularnych związków organicznych
w odciekach pochodzących ze składowiska ustabilizowanego (> 10 lat eksploatacji) oraz
ze składowiska młodego, 4-letniego. Autorzy wykazali, że w odciekach ze składowiska
starego dominowały związki o dużych masach molekularnych, z czego związki
o masie > 100 kDa oraz w przedziałach 50÷100 kDa i 30÷50 kDa stanowiły
odpowiednio 19, 20 i 17%. W odciekach ze składowiska młodego prawie 70% stanowiły
związki o masie < 0,5 kDa, w przedziale 0,5÷10 kDa występowało 12%, zaś molekuły
o masach powyżej 10 kDa stanowiły 18%. Badania Kang i współprac. [8] wykazały, że
w odciekach występują głównie substancje humusowe, których masy molekularne
mieszczą się w przedziale 10÷100 kDa, zaś molekuły o mniejszych masach (do 1 kDa)
Charakterystyka oraz metody usuwania zanieczyszczeń organicznych z odcieków …
391
stanowią 15÷19%. Podobnie Wu i współprac. [9] odnotowali, że w odciekach
pochodzących z ustabilizowanego składowiska odpadów komunalnych (stosunek
BZT5/ChZT ok. 0,06) ponad 50% stanowiły związki organiczne o masach molekularnych
większych niż 10 kDa, natomiast związki o masach poniżej 1 kDa obejmowały niespełna
20%.
Powszechnie uważa się, że odcieki zawierają związki organiczne uznawane za
niebezpieczne, w tym pestycydy, wielopierścieniowe węglowodory aromatyczne
(WWA), oraz aromatyczne związki zawierające chlor [10], pestycydy, głównie MCPP
i atrazynę [11], benzenosulfoniany i naftalenosulfoniany [12]. Badania przeprowadzone
przez Paxéusa [13] na 3 starych składowiskach odpadów komunalno-przemysłowych
wykazały, że wśród analizowanych 209 związków odnotowano obecność 39 potencjalnie
niebezpiecznych substancji organicznych, w tym związków chloroorganicznych:
chlorobenzen (0,1÷62 µg/dm3), dichlorobenzen (0,1÷57 µg/dm3), trichlorofenol
(0,3÷1,0 µg/dm3), tetrachlorofenol (0,0÷0,1 µg/dm3), pentachlorofenol (0,1÷0,2 µg/dm3),
chloroanilina (0,0÷5,0 µg/dm3); alkilowych węglowodorów aromatycznych: toluen
(1÷17 µg/dm3), etylobenzen (0,2÷179 µg/dm3), ksylen (0,3÷310 µg/dm3);
wielopierścieniowych
węglowodorów
aromatycznych
(WWA):
naftalen
(0,4÷400 µg/dm3), fenantren (0,6÷52 µg/dm3), fluoranten (1,0÷6,0 µg/dm3), piren
(3 µg/dm3) oraz ftalanów: dietyloftalan (0,0÷4,0 µg/dm3), dibutyloftalan
(0,0÷2,0 µg/dm3).
Shridharan i Didier (wg [14]) podają, że w odciekach zakresy stężeń benzenu i jego
alifatycznych pochodnych mogą zmieniać się w szerokim przedziale od 1 do
1630 µg/dm3 (benzen), 1÷1680 µg/dm3 (etylobenzen), 1÷11 800 µg/dm3 (toluen),
9,4÷240 µg/dm3 (ksylen). Spośród WWA acenaften występował w stężeniu
13,9÷21,3 µg/dm3, fluoren - 219÷32,6 µg/dm3, naftalen - 4,6÷186 µg/dm3, fenantren 8,11 220 µg/dm3. Buniak i współprac. [15] w odciekach ze składowiska odpadów
komunalnych w Maślicach odnotowali obecność 16 rodzajów WWA, których stężenie
wynosiło łącznie 7966 µg/dm3, w tym 70% stanowił acenaftylen.
Klimiuk i Kulikowska [16] wykazały, że w odciekach ze składowiska odpadów
komunalnych w Wysiece koło Bartoszyc stężenie BTX wyniosło 175,8 µg/dm3. Wśród
nich największe stężenia odnotowano w przypadku ksylenu (82,7 µg/dm3), a najmniejsze
- benzenu (0,6 µg/dm3). Stężenie związków chlorowcoorganicznych wyniosło
55,7 µg/dm3, z czego prawie 98% stanowił chloroform. Średnie stężenie chlorobenzenów
było niewielkie - 0,75 µg/dm3. Wśród WWA występował naftalen, acenaftalen,
acenaften, fluoren, fenantren, antracen, fluoranten, piren, benzo[a]antracen,
chryzen,
benzo[b]fluoranten,
benzo[k]fluoranten,
benzo[a]piren
oraz
indeno[1,2,3-c,d]piren, w przypadku PCB odnotowano jedynie niewielkie stężenie
2,2’,3,4,4’,5-heksachlorobifenylu (PCB 138).
Pomimo dużej złożoności składu chemicznego odcieków, większość autorów jako
miarę zawartości związków organicznych wykorzystuje wskaźniki BZT5 i ChZT. Wraz
z rosnącym wiekiem składowiska notuje się spadek zawartości związków organicznych
wyrażonych jako BZT5 i ChZT oraz zmniejszenie proporcji BZT5/ChZT, co związane
jest z faktem, że w ogólnej puli związków organicznych maleje udział kwasów lotnych
i innych małomolekularnych związków organicznych zaliczanych do łatwo
392
Dorota Kulikowska
rozkładalnych. Uważa się, że stosunek BZT5/ChZT stanowi miarę zachodzących na
składowisku przemian biochemicznych.
Dane literaturowe wskazują, że w odciekach ze składowisk młodych występują
związki organiczne charakteryzujące się stosunkowo dużą podatnością na biodegradację,
czego potwierdzeniem jest duża (przekraczająca 0,5) wartość stosunku BZT5/ChZT
[17-22]. Wraz z wiekiem składowiska następuje obniżenie podatności na biodegradację
związków organicznych oraz spadek stosunku BZT5/ChZT [23-28].
Obniżenie wartości stosunku BZT5/ChZT w odciekach wraz z wiekiem składowiska
potwierdzają badania Gau i współprac. [29], którzy wykazali, że w pierwszych
miesiącach eksploatacji stosunek BZT5/ChZT wynosił 0,6÷0,8, zaś po 5 latach zmalał do
0,2÷0,4. Podobnie Kang i współprac. [8] wykazali, że wraz ze wzrostem wieku
składowiska maleje ilość substancji organicznych wyrażonych zarówno BZT5, jak
i ChZT oraz stosunek BZT5/ChZT. Autorzy analizowali odcieki pochodzące ze
składowisk różniących się wiekiem (< 5 lat, 5-10 lat, > 10 lat) i wykazali, że w odciekach
ze składowiska młodego stosunek BZT5/ChZT wynosił 0,79, a w odciekach ze
składowiska o wieku > 10 lat był ponad 7-krotnie mniejszy (0,11).
Jednakże zdaniem Chen [30], rozkład biodegradowalnej materii organicznej na
składowiskach może zachodzić w znacznie krótszym czasie. Na podstawie badań
9 różnych składowisk odpadów komunalnych na Tajwanie autor wykazał, że
najintensywniejsze przemiany następują w ciągu pierwszych 18 miesięcy eksploatacji,
a następnie osiągana jest faza stabilizacji, czego odzwierciedleniem jest małe stężenie
związków organicznych wyrażonych jako BZT5 (poniżej 100 mg/dm3) oraz ChZT
(ok. 1000 mg/dm3). Zdaniem Reinhart i Al-Yousfi [31], na skrócenie czasu potrzebnego
do uzyskania stabilizacji z kilkudziesięciu do 2-3 lat ma wpływ recyrkulacja odcieków.
Potwierdzają to badania Chugh i współprac. [32], którzy odnotowali znaczne obniżenie
produkcji metanu oraz zawartości związków organicznych ChZT w odciekach, kiedy
objętość recyrkulowanych odcieków wynosiła 30% początkowej objętości złoża
składowiska. Podobne spostrzeżenia poczynili Aziz i współprac. [33] oraz Rodriguez
i współprac. [34], którzy wykazali, że nawet w odciekach pochodzących z młodych
składowisk stężenie związków organicznych wyrażonych jako ChZT jest małe.
Metody oczyszczania odcieków
Do oczyszczania odcieków składowiskowych stosowane są metody biologiczne,
fizykochemiczne oraz łączone. Wybór metody oczyszczania w dużej mierze zależy od
podatności na biodegradację występujących w odciekach związków organicznych.
Metody biologiczne zwykle stosowane są do odcieków pochodzących z młodych
składowisk, charakteryzujących się dużym stosunkiem BZT5/ChZT. Z przeglądu
piśmiennictwa wynika, że efektywność usuwania związków organicznych metodami
biologicznymi ulega znacznemu zmniejszeniu wówczas, gdy odcieki pochodzą ze starych
składowisk i zawierają głównie nierozkładalne substancje organiczne. Jako przykład
można podać badania Barbusińskiego i współprac. [35], którzy podczas oczyszczania
metodą osadu czynnego odcieków pochodzących z 50-letniego składowiska odpadów
przemysłowych (ChZT 1050 - 1500 mg/dm3) uzyskali efektywność usunięcia związków
organicznych na poziomie 7,5%. W trakcie badań odnotowali spadek aktywności
oddechowej mikroorganizmów oraz stopniową stabilizację i mineralizację osadu.
393
W takich przypadkach bardziej skuteczne okazują się metody fizykochemiczne,
takie jak koagulacja/flokulacja, adsorpcja, pogłębione utlenianie, oraz metody
membranowe [36-43].
Koagulacja/flokulacja
Procesy koagulacji/flokulacji są szeroko stosowane do oczyszczania odcieków
pochodzących z ustabilizowanych składowisk odpadów komunalnych jako oczyszczanie
wstępne przed metodami biologicznymi lub technikami membranowymi (np. odwróconą
osmozą) lub jako ostatni etap oczyszczania odcieków tzw. doczyszczanie. Zastosowanie
koagulacji do oczyszczania odcieków prowadzi do usunięcia z nich przede wszystkim
substancji o dużych masach molekularnych, czyli głównie substancji humusowych. Jako
koagulanty stosowane są najczęściej sole żelaza(III) i sole glinu oraz Ca(OH)2, przy
czym dane literaturowe wskazują, że najbardziej efektywne są sole żelaza. Amokrane
i współprac. [44] przy dawce siarczanu glinu wynoszącej 0,035 mola/dm3 uzyskali 42%,
a przy takiej samej dawce chlorku żelaza ok. 55% redukcję ChZT. Diamadopoulos [45]
wykazał, że efektywność usuwania związków organicznych (ChZT = 5690 mg/dm3)
wynosiła 56% przy zastosowaniu FeCl3 (0,8 g/dm3) oraz 39% przy zastosowaniu
Al2(SO4)3 (0,4 g/dm3).
Głównymi parametrami wpływającymi na efektywność procesu są dawka
koagulantu, odczyn oraz obecność substancji wspomagających.
Ze względu na fakt, że odcieki pochodzące z różnych składowisk charakteryzują się
różną zawartością refrakcyjnych związków organicznych, dawka koagulantu powinna
być określona doświadczalnie. Podobnie jest z odczynem, optymalna wartość pH
koagulacji zmienia się w zależności od składu odcieków, dawki koagulantu oraz rodzaju
koagulowanych cząstek.
W celu uzyskania dużych, łatwo sedymentujących kłaczków, w procesie koagulacji
stosowane są substancje wspomagające, m.in. bentonit, pylisty węgiel aktywny,
krzemionka, zeolity oraz flokulanty. Substancje wspomagające mogą być zarodkami do
powstawania nowych kłaczków bądź obciążnikami ułatwiającymi ich sedymentację.
Obciążnik może pełnić funkcję substancji przyspieszającej proces sedymentacji (kłaczki
są większe i cięższe) lub stanowić adsorbent, na którego powierzchni adsorbują się
rozpuszczone substancje [46].
Procesy koagulacji są polecane nie tylko do usuwania makromolekularnych
związków organicznych, ale też do usuwania metali. Jak podają Urase i współprac. [47],
efektywność usuwania metali z zastosowaniem FeCl3 (0,3 g/dm3) wynosiła 95÷98% dla
Zn(II), Cd(II) oraz Pb(II), a dla miedzi(II), niklu(II) i chromu(VI) była nieco mniejsza
(74÷87%). Wadą procesu koagulacji jest wrażliwość na zmiany pH, duża ilość
powstających osadów pokoagulacyjnych (nawet ok. 0,45 dm3 osadu/dm3 odcieków) [44]
oraz możliwość ich rozpuszczenia przy przedawkowaniu koagulantów [48].
Adsorpcja
W wyniku procesów adsorpcji z odcieków usuwane są trudno rozkładalne
zanieczyszczenia organiczne, w tym substancje humusowe oraz chlorowane
węglowodory. Procesy adsorpcji mogą być prowadzone w warunkach przepływowych
(np. z zastosowaniem kolumn) lub statycznych. Adsorpcja statyczna polega na
394
Dorota Kulikowska
tzw. adsorpcji porcjowej w kąpieli, tzn. dozowaniu adsorbentu do określonej porcji
roztworu i mieszaniu całości [46].
Jako adsorbenty stosowane są najczęściej węgiel aktywny, zeolity oraz żywice,
a efektywność procesu w dużej mierze zależy od rodzaju zastosowanego adsorbentu oraz
jego dawki.
Kargi i Pamukoglu [49] porównywali efektywność adsorpcji zanieczyszczeń
organicznych z odcieków składowiskowych na pylistym węglu aktywnym (PAC) oraz
pylistym zeolicie. Autorzy wykazali, że przy dawkach adsorbentów wynoszących
2 g/dm3 efektywność usuwania zanieczyszczeń organicznych wynosiła odpowiednio 87%
(PAC) i 77% (zeolit). Rodriguez i współprac. [50] do usuwania substancji humusowych
z odcieków zastosowali węgiel aktywny oraz żywice (XAD-8, XAD-4 oraz IR-20).
Z badań autorów wynika, że największą efektywność procesu i stężenie ChZT
w odpływie na poziomie 200 mg/dm3 uzyskano przy zastosowaniu węgla aktywnego.
W przypadku żywic sprawność procesu była dużo mniejsza, a stężenie związków
organicznych w odpływie pozostawało na poziomie o ChZT > 600 mg/dm3.
Zależność między efektywnością procesu adsorpcji a dawką adsorbentu
potwierdzają badania Rivas i współprac. [51]. Autorzy, stosując do usuwania
zanieczyszczeń organicznych z odcieków (ChZT 3500 mg/dm3) węgiel Norit
0,8, uzyskali w odpływie stężenie ChZT o wartości 2170 mg/dm3 (dla dawki 5 g/dm3),
1330 mg/dm3 (dla dawki 15 g/dm3) oraz 525 mg/dm3 (dla dawki 30 g/dm3), co
odpowiadało sprawności na poziomie odpowiednio 38%, 62% oraz 85%.
Adsorbenty pyliste często są wprowadzane do komór osadu czynnego. Z badań
Kargi i współprac. [52] wynika, że ponad 80% efektywność usuwania zanieczyszczeń
organicznych z odcieków składowiskowych można uzyskać, stosując metodę osadu
czynnego, wspomaganą adsorpcją na pylistym węglu aktywnym (PAC). Autorzy
wykazali, że w zależności od dawki PAC wprowadzanej do komory osadu czynnego,
efektywność usuwania zanieczyszczeń organicznych zmieniała się od 76% (przy dawce
0,25 g/dm3) do 87% (przy dawce 5 g/dm3). Jednocześnie autorzy wykazali, że
w odciekach poddanych wyłącznie procesom adsorpcji redukcja ChZT wynosiła od
17 do 50% (odpowiednio dla dawek węgla 0,25 i 5 g/dm3).
Stosowanie adsorbentów pylistych wymaga procesów umożliwiających ich usunięcie
z roztworu, np. filtracji, dlatego wielu autorów stosuje granulowany węgiel aktywny.
Rivas i współprac. [51] zastosowali do usuwania zanieczyszczeń organicznych
z odcieków węgiel granulowany Chemiviron AQ40 oraz Picacarb 1240. Uzyskana przez
autorów efektywność procesu kształtowała się na poziomie od 45% (Chemviron AQ40,
10 g/dm3) do 55% (Chemviron AQ40, 30 g/dm3) oraz od 20% (Picacarb 1240, 5 g/dm3)
do 40% (Picacarb 1240, 15 g/dm3).
Szybkość procesów adsorpcji z roztworów zależy od rozmiarów cząstek adsorbentu
- im cząstki są mniejsze, tym szybciej zachodzą procesy adsorpcji. Z tego powodu czas
potrzebny do uzyskania stężenia równowagowego w przypadku adsorbentów pylistych
jest dużo krótszy niż przy zastosowaniu adsorbentów granulowanych, charakteryzujących
się większymi rozmiarami cząstek.
Granulowany węgiel aktywny jest też często stosowany do oczyszczania odcieków
w układach przepływowych. Z badań Morawe i współprac. [53] wynika, że w kolumnie,
której wypełnienie stanowił węgiel granulowany Calgon Filtrasob 400, efektywność
usuwania ChZT kształtowała się na poziomie 90%, a przebicie kolumny nastąpiło
395
po 48 d. Znaczną (60%) redukcję zanieczyszczeń organicznych w kolumnie
z wypełnieniem z granulowanego węgla aktywnego (PHO 8/35 LBD) uzyskali
Kurniawan i współprac. [22].
Pogłębione utlenianie
Procesy pogłębionego utleniania stosowane są do rozkładu refrakcyjnych, tj. trudno
usuwalnych związków organicznych, a ich istotą jest wytworzenie silnie reaktywnych
rodników hydroksylowych •OH o potencjale 2,8 V. Rodniki te działają nieselektywnie,
szybko reagują z wieloma związkami organicznymi, tworząc rodniki organiczne (R•,
ROO• i inne), które, będąc produktami przejściowymi procesu utleniania, inicjują dalsze
łańcuchowe reakcje utleniania i degradacji [54].
Do wytwarzania rodników hydroksylowych stosuje się takie substancje chemiczne,
jak ozon, nadtlenek wodoru, i takie czynniki fizyczne, jak promieniowanie UV,
promieniowanie γ czy ultradźwięki. Dodatkowo można stosować katalizatory, np. TiO2,
Mn2+, Fe2+, Fe3+.
Chemiczne przemiany substancji przebiegające w trakcie utleniania prowadzą do
zmniejszenia ich masy molekularnej oraz prawie zawsze do zwiększenia ich podatności
na rozkład biologiczny.
Dane literaturowe wskazują, że do oczyszczania odcieków często wykorzystywany
jest odczynnik Fentona (Fe(II):H2O2). Efektywność usuwania substancji organicznych za
pomocą odczynnika Fentona badali Barbusiński i współprac. [35]. W przypadku dawek
od 2 do 5 g H2O2/dm3 uzyskali 54,6% zmniejszenie ChZT, co odpowiadało stężeniu
związków organicznych w odpływie na poziomie ChZT = 721 mg/dm3. Po utlenieniu
odczynnikiem Fentona nastąpiła zmiana proporcji BZT5/ChZT z 0,05 (odcieki surowe)
do 0,2 (odcieki oczyszczone), z czego wynika, że uzyskane produkty utleniania były
bardziej podatne na rozkład biochemiczny w porównaniu ze związkami organicznymi
występującymi w odciekach surowych.
Procesy pogłębionego utleniania są bardziej efektywne przy niskim odczynie,
mieszczącym się zazwyczaj w zakresie pH od 2,5 do 4 [43, 55]. Wzrost odczynu
powoduje spadek efektywności procesu, gdyż powstający Fe(OH)3 nie reaguje
z nadtlenkiem wodoru [56]. Zhang i współprac. [43] wykazali, że przy odczynie pH 2,5
reakcja Fentona przebiegała najefektywniej, a szybkość wytwarzania jonów żelaza(III)
była największa. Podobnie Surmacz-Górska i współprac. [40] wykazali wpływ pH na
efektywność procesu. Autorzy, stosując odczynnik Fentona w środowisku obojętnym,
uzyskali efektywność usunięcia zanieczyszczeń organicznych (ChZT) na poziomie
36÷38%. Procesowi degradacji towarzyszyło powstawanie dużych kłaczków osadów
chemicznych. Oczyszczone odcieki były bezbarwne i klarowne i zdaniem autorów
nadawały się do dalszego biologicznego oczyszczania. Korekta odczynu do pH 3
spowodowała zwiększenie efektywności oczyszczania do ok. 75÷78%, ale nie
następowała koagulacja, a oczyszczone odcieki charakteryzowały się intensywną
pomarańczową barwą.
Z danych literaturowych wynika, że w przypadku reakcji Fentona bardzo ważna jest
proporcja Fe(II):H2O2. Ustalenie optymalnej proporcji pozwala na uniknięcie
niepożądanych reakcji wolnorodnikowych, jakie mogą mieć miejsce przy nadmiarze obu
396
Dorota Kulikowska
reagentów, a powstające rodniki OH• są wykorzystywane głównie do utlenianie
substancji organicznych [57].
Wielu autorów wskazuje na możliwość poprawienia efektywności usuwania
zanieczyszczeń organicznych stosując metody fotochemiczne, czyli np. stosowania
odczynnika Fentona oraz promieniowania UV. Kim i współprac. [58] wykazali, że
szybkość rozkładu związków organicznych występujących w odciekach (ChZT 1150
mg/dm3, OWO [ogólny węgiel organiczny] 350 mg/dm3, BZT5 3÷5 mg/dm3) zależała od
dawki H2O2 i Fe(II) oraz intensywności napromieniowywania. W optymalnych
warunkach (dawka Fe(II) 1,0×10–3 mola/dm3, pH = 3, stosunek molowy ChZT:H2O2 1:1,
natężenie promieniowania 80 kW/m3) uzyskano ponad 70% redukcję ChZT.
Do oczyszczania odcieków często polecana jest metoda ozonowania. Ozon jest
silnym utleniaczem, reagującym w temperaturze otoczenia z większością związków
organicznych bezpośrednio albo pośrednio poprzez wytworzenie rodników. Ozon jest
reaktywny względem związków aromatycznych z podstawnikami elektronodonorowymi
(-OH, -NH2, -OCH3) oraz związków alifatycznych z podwójnym wiązaniem.
Proces ozonowania do oczyszczania odcieków składowiskowych (ChZT
ok. 3100 mg/dm3, BZT5 ok. 130 mg/dm3, stosunek BZT5/ChZT 0,05) zastosowali Bila
i współprac. [27]. Przy dawkach ozonu wynoszących 0,5, 1,5 oraz 3,0 g O3/dm3
efektywność usuwania związków organicznych wynosiła odpowiednio 0÷8%, 9÷15%
i 25÷50%, a stosunek BZT5/ChZT wzrósł do 0,1÷0,14 (0,5 g O3/dm3), 0,17÷0,25
(1,5 g O3/dm3) oraz 0,2÷0,3 (3,0 g O3/dm3).
Ze względu na fakt, że ozon łatwo reaguje ze związkami zawierającymi podwójne
wiązanie, trudniej natomiast z alifatycznymi związkami węgla, często przeprowadza się
aktywację tych związków za pomocą promieniowania ultrafioletowego. W wyniku tego
procesu powstają związki podatne na utlenianie ozonowe. Układ ozon/UV uważany jest
za jeden z bardziej skutecznych do rozkładu substancji, które praktycznie nie ulegają
degradacji przy użyciu wyłącznie ozonu [59].
Wu i współprac. [9] badali efektywność oczyszczania odcieków, stosując procesy
pogłębionego utleniania z zastosowaniem O3, O3/H2O2 oraz O3/UV. Stężenia związków
organicznych wyrażonych za pomocą ChZT i BZT5 wynosiły odpowiednio
6500 i 500 mg/dm3. Utlenianie zostało poprzedzone procesem koagulacji, stosując
chlorek żelaza (FeCl3) w stężeniu 900 mg/dm3, co pozwoliło na zmniejszenie wartości
ChZT do 2500 mg/dm3 i wzrost stosunku BZT5/ChZT do 0,1. Zastosowanie, jako
kolejnego stopnia oczyszczania, procesów utleniania (przy dawce ozonu 1,2 g/dm3)
spowodowało wzrost podatności na biodegradację zanieczyszczeń organicznych,
wyrażający się wzrostem stosunku BZT5/ChZT do 0,5.
Leitzke [39] opisał schemat instalacji oraz podał wyniki oczyszczania odcieków
metodą WEDECO - fotochemicznego utleniania na mokro za pomocą kombinowanej
metody O3/UV. Proces fotochemicznego utleniania, z zastosowaniem obiegów wodnego i gazowego - odbywał się pod ciśnieniem min. 5 bar abs. i temperaturze
0÷40°C. Przy czasie zatrzymania odcieków 4,3 h oraz dawce ozonu w ilości 480 g O3/h
lub 686 g O3/m3 uzyskał zmniejszenie wartości ChZT z 377 g O2/m3 do 77 g O2/m3. Przy
czasie zatrzymania 7,5 h oraz dawce ozonu 560 g O3/h lub 1400 g O3/m3 ChZT
w odciekach oczyszczonych zmniejszyło się do 32 g O2/m3. Z badań tego autora wynika
też, że obecność amoniaku w odciekach powoduje zwiększenie niezbędnej dawki ozonu.
Wzrost koniecznej dawki ozonu ma miejsce w przypadku odcieków niepoddanych
uprzednio oczyszczeniu biologicznemu bądź w odciekach
oczyszczeniu, ale o niedostatecznym stopniu nitryfikacji.
po
397
biologicznym
Metody membranowe
Procesy membranowe polegają na rozdzieleniu składników mieszaniny w wyniku jej
przepływu przez przepuszczalną membranę, a czynnikiem decydującym o stopniu
zatrzymywanych/przepuszczanych cząstek jest rozmiar ich porów. Siłą napędową
wywołującą przepływ przez membranę może być różnica ciśnień lub różnica potencjałów
chemicznych po obu jej stronach. Do oczyszczania odcieków ze składowisk odpadów
komunalnych stosowane są głównie ciśnieniowe procesy membranowe, tj. odwrócona
osmoza, nanofiltracja oraz ultrafiltracja.
Zastosowanie odwróconej osmozy pozwala na uzyskanie dużej efektywności
usuwania związków organicznych. Stępniak [60] metodą odwróconej osmozy uzyskał
w skali technicznej redukcję ChZT z 7300 do 15 mg/dm3, a BZT5 z 2100 do 5 mg/dm3.
Peters [61] w celu usunięcia zanieczyszczeń z odcieków składowiskowych (ChZT
ok. 1800 mg/dm3) zastosował dwustopniowy układ odwróconej osmozy. Proces
prowadzony był w temperaturze otoczenia i pod ciśnieniem 3,6÷6 MPa. Stężenie
związków organicznych ChZT po pierwszym i drugim stopniu wynosiło odpowiednio
382 i 20 mg/dm3, co odpowiadało sprawności procesu w całym układzie na poziomie
99,2%.
Do zalet odwróconej osmozy należy zaliczyć możliwość bardzo dużej (ponad 99%)
efektywności usunięcia substancji organicznych oraz metali ciężkich. Z badań Bilstada
i Madlanda [62] wynika, że przy zastosowaniu odwróconej osmozy można uzyskać
prawie 100% efektywność usuwania zawiesin organicznych i chromu, 99% usunięcie
żelaza, miedzi, cynku i fosforu oraz 97,1% ubytek OWO.
Poważną wadą odwróconej osmozy jest powstawanie koncentratu, stanowiącego od
20 do 25% wyjściowej objętości odcieków, w którym występują wszystkie zatrzymane
substancje w niezmienionej formie chemicznej.
Nanofiltracja jest stosowana do usuwania z odcieków zanieczyszczeń o masie
molekularnej większej niż 300 oraz metali. Trebouet i współprac. [63] zastosowali
proces nanofiltracji do oczyszczania odcieków, w których stężenie związków
organicznych wyrażonych za pomocą ChZT i BZT5 wynosiło odpowiednio 500
i 7,1 mg/dm3. Autorzy przetestowali 2 membrany: MPT-20 oraz MPT-31. Zastosowanie
membrany MPT-20 umożliwiło uzyskanie 74% redukcji zanieczyszczeń organicznych
wyrażonych jako ChZT i 85% jako BZT5, zaś w przypadku membrany MPT-31
uzyskano odpowiednio 80 i 98% redukcję tych zanieczyszczeń.
Wielostopniowe układy oczyszczania odcieków
W wielu przypadkach, gdy pojedyncze procesy oczyszczania nie są wystarczająco
efektywne w usuwania zanieczyszczeń organicznych zawartych w odciekach, stosuje się
układy wielostopniowe, w których łączy się procesy fizyczne, chemiczne i biologiczne.
W przypadku metod fizykochemicznych najczęściej stosowane jest łączenie metod
pogłębionego utleniania z koagulacją i adsorpcją.
Kurniawan i współprac. [22] porównali efektywność usuwania zanieczyszczeń
organicznych metodą ozonowania oraz ozonowania z adsorpcją na granulowanym węglu
398
Dorota Kulikowska
aktywnym. W wyniku ozonowania (przy dawce 3 g O3/dm3) uzyskano 35% redukcję
ChZT z odcieków o początkowym stężeniu tego wskaźnika wynoszącym 8000 mg/dm3.
Połączenie metod doprowadziło do obniżenia ChZT o 86% oraz zwiększenia stosunku
BZT5/ChZT z 0,09 do 0,47.
Silva i współprac. [64] do usuwania związków organicznych z odcieków
pochodzących z ustabilizowanego składowiska odpadów komunalnych (ChZT
3460 mg/dm3, BZT5/ChZT = 0,04) zastosowali koagulację/flokulację oraz ozonowanie.
Autorzy wykazali, że w wyniku koagulacji uzyskano 70% efektywność w usuwaniu
barwy i jedynie 23÷27% efektywność mierzoną jako ChZT usuwania związków
organicznych. W wyniku ozonowania uzyskano dalszą 50% redukcję związków
organicznych, ale wymagało to zastosowania dużej dawki ozonu (3 g O3/dm3).
Yoon i współprac. [65] porównali efektywność usuwania zanieczyszczeń organicznych
z odcieków przy zastosowaniu odczynnika Fentona oraz koagulacji. Podczas utleniania
odczynnikiem Fentona dawka H2O2 wynosiła 1 g/dm3, a ilość FeSO4⋅7H2O stanowiła
1,25 masy dawki H2O2. Jako koagulant zastosowano FeCl3 (w dawce 800÷1000 mg/dm3).
W celu regulacji odczynu do pH 5 użyto H2SO4. Z badań autorów wynika, że podczas
koagulacji usunięto od 59 do 73% substancji organicznych o masie molekularnej powyżej
500 i tylko 18% substancji o masie poniżej 500. Przy zastosowaniu odczynnika Fentona
efektywność usuwania substancji organicznych o masie powyżej i poniżej 500 wyniosła
odpowiednio 72÷89% i 43%.
Zamora i współprac. [66] porównali efektywność usuwania związków organicznych
z odcieków przy użyciu metod:
I - koagulacji-flokulacji (1°) i adsorpcji na węglu aktywnym (2°),
II - utleniania odczynnikiem Fentona (1°) i adsorpcji na węglu aktywnym (2°).
Zdaniem autorów, w przypadku oczyszczania odcieków korzystniejsza była druga
metoda, w której uzyskano prawie dwukrotnie lepsze usunięcie barwy oraz sprawność
usuwania ChZT większą o 30÷50%, w porównaniu z koagulacją-flokulacją połączoną
z adsorpcją na węglu aktywnym.
Monje-Ramirez i Valesquez [26] ozonowali odcieki (ChZT 3250 mg/dm3,
BZT5/ChZT 0,006) po koagulacji roztworem FeCl3. W wyniku procesu koagulacji przy
dawce FeCl3 równej 2,4 mg/dm3 stężenie zanieczyszczeń organicznych zmniejszyło się
o 67%. Połączenie procesów ozonowania (1,7 mg O3/mg ChZT) i koagulacji
(2,4 mg FeCl3/dm3) pozwoliło na 78% redukcję ChZT.
Chemiczne przemiany substancji organicznych przebiegające podczas procesów
pogłębionego utleniania prowadzą do zwiększenia ich podatności na biochemiczny
rozkład [9, 22, 27, 35]. Stąd w przypadku usuwania związków organicznych z odcieków
jest celowe łączenie metod biologicznych z chemicznymi.
Bila i współprac. [27] badali efektywność oczyszczania odcieków (ChZT
ok. 3100 mg/dm3, BZT5 ok. 130 mg/dm3, stosunek BZT5/ChZT 0,05) w układzie
wielostopniowym z zastosowaniem koagulacji/flokulacji (przy użyciu Al2(SO4)),
ozonowania (dawki ozonu: 0,5; 1,5; 3,0 g/dm3) oraz metody osadu czynnego. W wyniku
połączenia tych metod osiągnięto redukcję ChZT na poziomie 33÷38%
(koagulacja/flokulacja + ozonowanie, dawka ozonu 0,5 g O3/dm3 + metoda osadu
czynnego), 54÷74% (koagulacja/flokulacja + ozonowanie, dawka ozonu 1,5 g O3/dm3 +
metoda osadu czynnego) oraz 62÷84% (koagulacja/flokulacja + ozonowanie, dawka
ozonu 3,0 g O3/dm3 + metoda osadu czynnego).
399
Lin i Chang [66] do oczyszczania odcieków pochodzących ze składowiska
eksploatowanego dłużej niż 5 lat zastosowali układ trójstopniowy, w którym pierwszy
stopień stanowiła koagulacja z użyciem PAC-u i polimerów, drugi - utlenianie
elektrochemiczne wspomagane odczynnikiem Fentona oraz trzeci - oczyszczanie
biologiczne metodą osadu czynnego w reaktorach SBR. Stężenie związków organicznych
ChZT w odciekach wynosiło 1941 mg/dm3, a stosunek BZT/ChZT kształtował się na
poziomie 0,1. Po procesie koagulacji usunięcie związków organicznych ChZT wyniosło
ok. 55% (przy pH 5 i poniżej oraz dawce PAC 200 mg/dm3). Po 2 stopniu oczyszczania
nastąpił dalszy spadek stężenia związków organicznych do 295 mg/dm3 (dawka H2O2
750 mg/dm3, czas reakcji 23 min). Odcieki po 2 stopniu oczyszczania mieszano ze ściekami
miejskimi w proporcji 1:3. Sprawność usuwania związków organicznych w mieszaninie
odcieków i ścieków miejskich w reaktorze SBR wyniosła ok. 70%, co odpowiadało ich
stężeniu ChZT w odpływie na poziomie 80÷90 mg/dm3.
Jans i współprac. [37] oczyszczali odcieki w układzie: beztlenowy reaktor UASB
i odwrócona osmoza. Oczyszczaniu poddano odcieki o zawartości związków
organicznych wyrażonych jako ChZT od 25000 do 35000 mg/dm3. W odpływie
z reaktora UASB uzyskano stężenie związków organicznych o ChZT w zakresie od
3000 do 5000 mg/dm3. Układ do odwróconej osmozy składał się z dwóch sekcji.
W sekcji pierwszej znajdowały się moduły z membranami rurowymi o wewnętrznej
średnicy 1 cm. Ich zadaniem było zatrzymanie substancji występujących w fazie
zawiesin. W sekcji drugiej znajdowały się moduły z membranami spiralnymi, które
zatrzymywały substancje rozpuszczone. Proces prowadzono w temperaturze 30÷33°C.
W odpływie po odwróconej osmozie ChZT odcieków wyniosło 5÷8 mg/dm3.
Podsumowanie
Skład chemiczny odcieków ze składowisk odpadów komunalnych oraz stężenia
zawartych w nich zanieczyszczeń są zróżnicowane i zależą od wielu czynników, m.in.
wieku składowiska. W początkowym etapie eksploatacji w odciekach znajdują się
produkty typowe dla fermentacji kwaśnej - kwasy lotne oraz inne małomolekularne
związki organiczne, zaliczane do łatwo rozkładalnych. Wraz z wiekiem składowiska
w ogólnej puli związków organicznych maleje udział ww. substancji na rzecz związków
makromolekularnych, głównie kwasów humusowych. Cechą charakterystyczną składu
odcieków jest również występowanie związków organicznych uznawanych za
niebezpieczne.
Złożoność składu chemicznego odcieków jest powodem, że do ich oczyszczania
stosowane są zarówno metody fizykochemiczne, jak i biologiczne, przy czym do
usuwania trudno rozkładalnych zanieczyszczeń organicznych z odcieków ze składowisk
ustabilizowanych polecane są głównie metody fizykochemiczne, m.in. adsorpcja,
pogłębione utlenianie czy metody membranowe. Należy jednak zwrócić uwagę na fakt,
że w celu uzyskania bardzo dobrej jakości odpływu konieczne jest stosowanie układów
wielostopniowych.
Literatura
[1]
Burrows W.D. i Rowe R.S.: Ether soluble constituents of landfill leachate. J. Water Pollut. Control
Federation 1975, 47(5), 921-923.
400
Dorota Kulikowska
[2]
[3]
Chian E.S.K.: Stability of organic matter in landfill leachates. Water Res., 1977, 11, 225-232.
Harmsen J.: Identification of organic compounds in leachate from a waste tip. Water Res., 1983, 17(6),
699-705.
Ehrig H. J.: Treatment of sanitary landfill leachate: biological treatment. Waste Manage. Res., 1984, 2
131-152.
Artiola-Fortuny J. i Fuller W.H.: Humic substances in landfill leachates: I. Humic acid extraction and
identification. J. Environ. Qual., 1982, 11, 663-669.
Bolea E., Gorriz M.P., Bouby M., Laborda F., Castillo J.R. i Geckeis H.: Multielement characterization
of metal-humic substances complexation by size exclusion chromatography, asymmetrical flow
field-flow fractionation, ultrafiltration and inductively coupled plasma-mass spectrometry detection:
A comparative approach. J. Chromatogr., 2006, A1129, 236-246.
Calace N., Liberatori A., Petronio B.M. i Pietroletti M.: Characteristic of different molecular weight
fractions of organic matter in landfill leachate and their role in soil sorption of heavy metals. Environ.
Pollut., 2001, 113, 331-339.
Kang K., Shin H.S. i Park H.: Characterization of humic substances present in landfill leachates with
different landfill ages and its implications. Water Res., 2002, 36, 4023-4032.
Wu J.J., Wu C.-C., Ma H.-W. i Chang Ch.-Ch.: Treatment of landfill leachate by ozone-based advanced
oxidation processes. Chemosphere, 2004, 54, 997-1003.
Murray H. E. i Beck J. N.: Concetrations of synthetic organic chemicals in leachate from a municipal
landfill. Environ. Pollut., 1990, 67, 195-203.
Rügge K., Bjerg P. L., Mosbaek H. i Christensen T. H.: Fate of MCPP and atrazine in an anaerobic
landfill leachate plume (Grindsted, Denmark). Water Res., 1999, 33(10), 2455-2458.
Riediker S., Suter M.J.-F. i Giger W.: Benzene - and naphthalenesulfonates in leachates and plumes of
landfills. Water. Res., 2000, 34(7), 2069-2079.
Paxéus N.: Organic compounds in municipal landfill leachates. Water Sci. Technol., 2000, 42(7-8),
323-333.
Andreottola G. i Cannas P.: Chemical and biological characteristics of landfill leachate. [In:]
Landfilling of waste: leachate. Elsevier Applied Science. London and New York 1992, 65-88.
Buniak W., Jagiełło-Rymaszewska E. i Szymańska-Pulikowska A.: Zawartość wielopierścieniowych
węglowodorów aromatycznych oraz metali ciężkich w odciekach z wysypiska odpadów komunalnych.
V Konf. Nauk.-Techn. Gospodarka odpadami komunalnymi. Koszalin-Kołobrzeg 1997, 189-197.
Klimiuk E. i Kulikowska D.: Effectiveness of organics and nitrogen removal from municipal landfill
leachate in single and two-stage SBR systems. Polish J. Environ. Stud., 2004, 13(5), 525-532.
Robinson H. D. i Maris P. J.: The treatment of leachates from domestic wastes in landfills I. Aerobic
biological treatment of a medium - strength leachate. Water Res., 1983, 17(11), 1537-1548.
Henry J.G., Prasad D. i Young H.: Removal of organics from leachates by anaerobic filter. Water Res.,
1987, 21(11), 1395-1399.
Robinson H.D. i Grantham G.: The treatment of landfill leachates in on-site aerated lagoon plants:
experience in Britain and Ireland. Water Res., 1988, 22(6), 733-747.
Chang J-E.: Treatment of landfill leachate with an upflow anaerobic reactor combining a sludge bed
and a filter. Water Sci. Technol., 1989, 21, 133-143.
Timur H. i Özturk I.: Anaerobic treatment of leachate using sequencing batch reactor and hybrid bed
filter. Water Sci. Technol., 1997, 36(6-7), 501-508.
Kurniawan T.A., Lo W.-H. i Chan G.Y.S.: Degradation of recalcitrant compounds from stabilized
landfill leachate using a combination of ozone-GAC adsorption treatment. J. Hazard. Mater., 2006,
B137, 443-455.
Knox K.: Leachate treatment with nitrification of ammonia. Water Res., 1985, 19(7), 895-904.
Albers H. i Krückeberg G.: Combination of aerobic pre-treatment, carbon adsorption and coagulation.
[In:] Landfilling of waste: leachate. Elsevier applied science. London and New York 1992., 305-312.
Welander U., Henrysson T. i Welander T.: Nitrification of landfill leachate using suspended-carrier
biofilm technology. Water Res., 1997, 31, 2351-2355.
Monje-Ramirez I. i Orta de Velasquez M.T.: Removal and transformation of recalcitrant organic matter
from stabilized saline landfill leachates by coagulation-ozonation coupling processes. Water Res.,
2004, 38, 2358-2366.
Bila D.M., Montalvão A.F., Silva A.C. i Dezotti M.: Ozonation of andfill leachate: evaluation of toxicity
removal and biodegradability improvement. J. Hazard. Mater., 2005, B117, 235-242.
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
401
[28] Fan H.-J., Chen I.-W,. Lee M.-H. i Chiu T.: Using FeGAC/H2O2 process for landfill leachate treatment.
Chemosphere, 2007, 67, 1647-1652.
[29] Gau S.H., Chiang P.C. i Chang F.S.: A study on the procedure of leachate treatment by Fenton method.
Proc. 16th Conf. on Wastewater Treatment Technology in Republic of China, Taiwan, 1991, 527-537.
[30] Chen P.H.: Assessment of leachates from sanitary landfills: Impact of age, rainfall, and treatment.
Environ. Int., 1996, 22, 225-237.
[31] Reinhart D.R. i Al-Yousfi A.B.: The impact of leachate recirculation on municipal solid waste
operating characteristics. Waste Manage. Res., 1996, 14, 337-346.
[32] Chugh S., Clarke W., Pullammanappallil P. i Rudolph V.: Effect of recirculated leachate volume on
MSW degradation. Waste. Manage. Res., 1998, 16, 564-573.
[33] Aziz H.A., Alias S., Adlan M.N., Faridah, Asaari A.H. i Zahari M.S.: Colour removal from landfill
leachate by coagulation and flocculation processes. Biores. Technol., 2007, 98, 218-220.
[34] Rodriguez J., Castrillón L., Marañón E., Sastre H. i Fernàndez E.: Removal of non-biodegradable
organic matter from landfill leachates by adsorption. Water Res., 2004, 38, 3297-3303.
[35] Barbusiński K., Kościelniak H. i Majer M.: Oczyszczanie wód podziemnych zalegających pod
składowiskiem odpadów przemysłowych. V Ogólnopol. Sympoz. Nauk.-Techn. „Biotechnologia
Środowiskowa” 1997, 219-225.
[36] Hosomi M., Matsusige K., Inamori Y., Sudo R., Yamada K. i Yoshino Z.: Sequencing batch reactor
activated sludge processes for the treatment of municipal landfill leachate: removal of nitrogen and
refractory organic compounds. Water Sci. Technol., 1989, 21, 1651-1654.
[37] Jans J. M., van der Schroeff A. i Jaap A.: Combination of UASB pre - treatment and reverse osmosis.
[W:] Landfilling of waste: leachate. Elsevier Applied Science, London and New York 1992, 313- 321.
[38] Weber B. i Holz F.: Combination of activated sludge pre-treatment and reverse osmosis. [In:]
Landfilling of waste: leachate. Elsevier Applied Science. London and New York 1992., 203-210.
[39] Leitzke O.: Obróbka ścieków z wysypisk metodą fotochemicznego utleniania na mokro. Roczn. PZH,
1996, 1/47, 125-134.
[40] Surmacz-Górska J., Miksch K., Kierońska T. i Kita M.: Chemiczne i biologiczne utlenianie
zanieczyszczeń występujących w odciekach wysypiskowych. V Ogólnopol. Sympoz. Nauk.-Techn.
„Biotechnologia Środowiskowa”, 1997, 239-247.
[41] Ince N.H.: Light - enhanced chemical oxidation for tertiary treatment of municipal landfill leachate.
Water Environ. Res., 1998, 70(6), 1161-1169.
[42] Chianese A., Ranauro R. i Verdone N.: Treatment of landfill leachate by reverse osmosis. Water Res.,
1999, 33(3), 647-652.
[43] Zhang H., Choi H. J. i Huang Ch-P.: Optimization of Fenton process for the treatment of landfill
leachate. J. Hazard. Mater., 2005, B125, 166-174.
[44] Amokrane A., Comel C. i Veron J.: Landfill leachates pretreatment by coagulation - flocculation. Water
Res., 1997, 31(11), 2775-2782.
[45] Diamadopoulos E.: Characterization and treatment of recirculation-stabilized leachate. Water Res.,
1994, 2439-2445.
[46] Anielak A.M.: Chemiczne i fizykochemiczne oczyszczanie ścieków. WN PWN, Warszawa 2000.
[47] Urase T., Selequzzaman M., Kobayashi S., Matsuo T., Yamamoto K. i Suzuki N.: Effect of high
concentration of organic and inorganic matters in landfill leachate on the treatment of heavy metals in
very low concentration level. Water Sci. Technol., 1997, 36, 349-356.
[48] Rosik-Dulewska C.: Podstawy gospodarki odpadami. WN PWN, Warszawa 2000.
[49] Kargi F. i Pamukoglu M.Y.: Adsorbent supplemend biological treatment of pre-treated landfill leachate
by fed-batch operation. Biores. Technol., 2004, 94, 285-291.
[50] Rodriguez J., Castrillón L., Marañón E., Sastre H. i Fernàndez E.: Removal of non-biodegradable
organic matter from landfill leachates by adsorption. Water Res., 2004, 38, 3297-3303.
[51] Rivas F.J., Beltrán F., Gimeno O., Acedo B. i Carvalho F.: Stabilized leachates: ozone-activated carbon
treatment and kinetics. Water Res., 2003, 37, 4823-4834.
[52] Kargi F. i Pomukoglu M.Y.: Powdered activated carbon added biological treatment of pre-treated
landfill leachate in a fed-batch reactor. Biotechnol. Lett., 2003, 25, 695-699.
[53] Morawe B., Ramteke D.S. i Vogelpohl A.: Activated carbon column performance studies of biologically
treated landfill leachate. Chem. Eng. Process., 1995, 34, 299-303.
[54] Biń A.K. i Wąsowski J.: Procesy zaawansowanego utleniania chemicznego w uzdatnianiu wód
podziemnych. Wyd. PW, Warszawa 1996.
402
Dorota Kulikowska
[55] Chou S. i Huang C.: Effect of Fe2+ on catalytic oxidation in a fluidized bed reactor. Chemosphere, 1999,
39, 1997-2006.
[56] Liu Y. i Tay J-H.: Strategy for minimization of excess sludge production from the activated sludge
process. Biotechnol. Advances, 2001, 19, 97-107.
[57] Lopez A., Pagano M., Volpe A. i di Pinto A.C.: Fenton’s pre-treatment of mature landfill leachate.
Chemosphere, 2004, 54, 1005-1010.
[58] Kim S.-M., Geissen S.- U. i Vogelpohl A.: Landfill leachate treatment by a photoassisted Fenton
reaction. Water Sci. Technol., 1997, 35(4), 239-248.
[59] Biń A.K.: Procesy pogłębionego utleniania wody i ścieków. Materiały konferencyjne „Kompleksowe
i szczegółowe problemy inżynierii środowiska”, Ustronie Morskie 1997.
[60] Stępniak S.: Oczyszczanie odcieków. Ekoprofit, 1998, 1, 35-39.
[61] Peters T.A.: Purification of landfill leachate with reverse osmosis and nanofiltration. Desalitation,
1998, 119, 289-293.
[62] Bilstad T. i Madland M.V.: Leachate minimization by reverse osmosis. Water Sci. Technol., 1992,
25(3), 117-120.
[63] Trebouet D., Schlumpf J.P., Jaouen P. i Quemeneur F.: Stabilized landfill leachate treatment by
combined physicochemical-nanofiltration process. Water Res., 2001, 35, 2935-2942.
[64] Silva A.C., Dezotti M. i Sant’Anna Jr. G.L.: Treatment and detoxification of a sanitary landfill leachate.
Chemosphere, 2004, 55, 207-214.
[65] Yoon J., Cho S. i Kim S.: The characteristics of coagulation of Fenton reaction in the removal of
landfill leachate organics. Water Sci. Technol., 1998, 38(2), 209-214.
[66] Zamora R.M.R., Moreno A.D, Orta de Velasquez M.T. i Ramirez I.M.: Treatment of landfill leachates
by comparing advanced oxidation and coagulation-flocculation processes coupled with activated
carbon adsorption. Water Sci.Technol., 2000, 41(1), 231-235.
[67] Lin S.H. i Chang Ch.C.: Treatment of landfill leachate by combined electro-Fenton oxidation and
sequencing batch reactor method. Water Res., 2000, 34, 4243-4249.
CHARACTARIZATION OF ORGANICS AND METHODS TREATMENT
OF LEACHATE FROM STABILIZED MUNICIPAL LANDFILLS
Faculty of Environmental Sciences and Fisheries, University of Warmia and Mazury in Olsztyn
Abstract: The characteristic of organic substances in municipal landfill leachate was presented and the
influence of landfill age on organics concentrations was discussed. The occurrence of hazardous compounds
like BTEX, polyaromatic hydrocarbons (PAH) and chlorinated compounds were analysed. Moreover, the most
popular physico-chemical methods treatment was reviewed. A particular focus was given to
coagulation/flocculation, adsorption, advanced oxidation processes and membrane processes.
Keywords: landfill leachate, organic substances, BETX, PAH, coagulation/flocculation, adsorption, advanced
oxidation processes, membrane processes
VARIA
15th ICHMET
15th INTERNATIONAL CONFERENCE
ON HEAVY METALS IN THE ENVIRONMENT
SEPTEMBER 19-23, 2010
GDAŃSK, POLAND
ORGANIZED BY
CHEMICAL FACULTY, GDANSK UNIVERSITY OF TECHNOLOGY (GUT)
TOGETHER WITH
COMMITTEE ON ANALYTICAL CHEMISTRY
OF THE POLISH ACADEMY OF SCIENCES (PAS)
15th ICHMET- is a continuation of a series of highly successful conferences that have
been held in major cities of the world since 1975. These conferences typically draw
500-1000 participants from countries in many parts of the world. Well over 5000
scientists have taken part in this series of conferences including most leaders in the field.
Apart from the city’s natural beauty, Gdańsk is logical choice for the 15th Conference to
highlight the outstanding work that is being done on heavy metals in Central Europe.
The venue for the meeting will be the Gdansk University of Technology (GUT) which
features many tourist attractions.
The Conference will include a number of invited lectures treating frontier topics
prepared by specialist with international reputation, oral presentation and poster sessions.
ICHMET welcomes contributions on all aspects of any heavy metal in the environment.
All presentation will be connected with such topics as:
Risk assessment and risk management pertaining to toxic metals in the environment
Susceptibility and protection of children from toxic metals in their environment
Measurement and exposure assessment
Biomarkers of exposure and effects of heavy metals
Gene-environment-metal interactions
Trend tracking/analysis of heavy metal data - spatial and temporal
Risk communication pertaining to heavy metals
Life cycle analysis for metalliferous consumer products
Soil quality criteria
Remediation technologies
Control strategies for heavy metal emissions and deposition
Metal mixtures - mechanistic and epidemiological studies
Nutrient-metal interactions
Advancements in analytical tools (procedures and measurement devices)
Toxicology of heavy metals, from cellular and genomic to ecosystem levels
406
Heavy metals in foods
Impact of global change on heavy metal cycle
For further information on the conference, please contact:
Professor Jacek Namieśnik (Conference Chairman)
Gdansk University of Technology, Chemical Faculty
Department of Analytical Chemistry
G. Narutowicza 11/12, 80-233 Gdańsk (Poland)
homepage: http://www.pg.gda.pl/chem/ichmet/
INVITATION FOR ECOpole’09 CONFERENCE
CHEMICAL SUBSTANCES IN ENVIRONMENT
We have the honour to invite you to take part in the 18th annual Central European
Conference ECOpole'09, which will be held in 14-17 X 2009 (Thursday-Saturday) on
Wilhelms Hill at Uroczysko in Piechowice, the Sudety Mts., Lower Silesia, PL.
The Conference Programme includes oral presentations and posters and will be
divided into five sections - SI-SV:
• SI Chemical Pollution of Natural Environment and its Monitoring
• SII Environment Friendly Production and Use of Energy
• SIII Risk, Crisis and Security Management
• SIV Forum of Young Scientists and Environmental Education in Chemistry
• SV Impact of Environment Pollution on Food and Human Health
During the Conference the books exhibition printed by the Polish Publishing House
Wydawnictwa Naukowo-Techniczne (WNT), Warsaw will be organised.
The Conference language is English.
Contributions to the Conference will be published as:
• abstracts on the CD-ROM (0.5 page of A4 paper sheet format)
• extended Abstracts (4-6 pages) in the semi-annual journal Proceedings of ECOpole
full papers will be published in successive issues of the Ecological Chemistry and
Engineering/Chemia i Inżynieria Ekologiczna (Ecol. Chem. Eng.) ser. A and S.
Additional information one could find on the website:
ecopole.uni.opole.pl
The deadline for sending the Abstracts is 31.08.2009 and for the Extended Abstracts:
1.10.2009. The actualised list (and the Abstracts) of the Conference contributions
accepted for presentation by the Scientific Board, one can find (starting from
15.07.2009) on the Conference website.
The papers must be prepared according to the Guide for Authors on Submission
of Manuscripts to the Journals.
408
The Conference fee is 300 € (covering hotel, meals and transportation during the
Conference). It could be reduced (to 170 €) for young people actively participating in the
Forum of Young Scientists. But the colleague has to deliver earlier the Extended
Abstract (4-6 pages) of his/her contribution (deadline is on 15.08.2009), and
a recommendation of his/her Professor.
Fees transferred after 15.09.2009 are 10% higher.
Please, fill in the Registration Form and send via email or fax.
At the Reception Desk each participant will obtain a CD-ROM with abstracts of the
Conference contributions as well as Conference Programme (the Programme will be also
published on this site).
Further information is available from:
Dr hab. Maria Wacławek, prof. UO
Chairperson of the Conference Organising Committee
University of Opole
and [email protected]
phone +48 77 455 91 49 and +48 77 401 60 42
fax +48 77 401 60 51
Conference series
1. 1992 Monitoring’92 Opole
2. 1993 Monitoring’93 Turawa
3. 1994 Monitoring’94 Pokrzywna
4. 1995 EKO-Opole’95 Turawa
5. 1996 EKO-Opole’96 Kędzierzyn-Koźle
6. 1997 EKO-Opole’97 Duszniki Zdrój
7. 1998 CEC ECOpole’98 Kędzierzyn-Koźle
8. 1999 CEC ECOpole’99 Duszniki Zdrój
9. 2000 CEC ECOpole 2000 Duszniki Zdrój
17. 2008 CEC ECOpole’08 Piechowice
409
REGISTRATION FORM for the ECOpole’09 CONFERENCE
Surname and First Name .....................................................................................................
Scientific Title/Position .......................................................................................................
Affiliation ............................................................................................................................
Address ...............................................................................................................................
Tel./fax.........................................................., email ...........................................................
Title of presentation ............................................................................................................
.............................................................................................................................................
KIND OF PRESENTATION
YES
NO
Oral
Poster
Taking part in
discussion
ACCOMMODATION
14/15 X
Yes
No
15/16 X
Yes
16/17 X
No
Yeas
No
MEALS
Date
14 X
15 X
16 X
17 X
Breakfast
---
Lunch
---
Dinner
---
ZAPRASZAMY
DO UDZIAŁU W ŚRODKOWOEUROPEJSKIEJ KONFERENCJI
ECOpole’09
W DNIACH 14-17 X 2009
SUBSTANCJE CHEMICZNE W ŚRODOWISKU PRZYRODNICZYM
Będzie to osiemnasta z rzędu konferencja poświęcona badaniom podstawowym oraz
działaniom praktycznym, dotycząca różnych aspektów ochrony środowiska przyrodniczego. Odbędzie się ona w ośrodku „Uroczysko” na Wzgórzu Wilhelma
w Piechowicach koło Szklarskiej Poręby. Doroczne konferencje ECOpole mają charakter
międzynarodowy i za takie są uznane przez Ministerstwo Nauki i Szkolnictwa Wyższego. Obrady konferencji ECOpole’09 będą zgrupowane w pięciu Sekcjach SI-SV:
• SI Chemiczne substancje w środowisku przyrodniczym oraz ich monitoring
• SII Odnawialne źródła energii i jej oszczędne pozyskiwanie oraz użytkowanie
• SIII Zarządzanie środowiskiem w warunkach kryzysowych
• SIV Forum Młodych (FM) i Edukacja prośrodowiskowa w chemii
• SV Wpływ zanieczyszczeń środowiska oraz żywności na zdrowie ludzi
W czasie konferencji zostanie zorganizowana wystawa książek związanych z tematyką konferencji opublikowanych przez Wydawnictwa Naukowo-Techniczne (WNT)
w Warszawie, połączona z ich sprzedażą.
Materiały konferencyjne będą opublikowane w postaci:
• abstraktów (0,5 strony formatu A4) na CD-ROM-ie;
• rozszerzonych streszczeń o objętości 4-6 stron w półroczniku Proceedings of
ECOpole;
• artykułów w abstraktowanych czasopismach: Ecological Chemistry and Engineering/Chemia i Inżynieria Ekologiczna (Ecol. Chem. Eng.) ser. A i S oraz niektórych
w półroczniku Chemia-Dydaktyka-Ekologia-Metrologia.
Termin nadsyłania angielskiego i polskiego streszczenia o objętości 0,5-1,0 strony (wersja cyfrowa + wydruk) planowanych wystąpień upływa w dniu 31 sierpnia
2009 r. Lista prac zakwalifikowanych przez Radę Naukową Konferencji do prezentacji
jest sukcesywnie publikowana od 15 lipca 2009 r. na stronie webowej konferencji
412
ecopole.uni.opole.pl
Koszt uczestnictwa w całej konferencji wynosi 1000 zł i pokrywa opłatę za udział,
koszt noclegów i wyżywienia oraz rocznej prenumeraty Ecol. Chem. Eng. ser. A oraz S
(razem blisko 2000 ss.) łącznie z Proceedings of ECOpole. Jest możliwość udziału tylko
w jednym wybranym przez siebie dniu, wówczas opłata wyniesie 650 zł i będzie upoważniała do uzyskania wszystkich materiałów konferencyjnych, jednego noclegu i trzech
posiłków (śniadanie, obiad, kolacja), natomiast osoby zainteresowane udziałem w dwóch
dniach, tj. w pierwszym i drugim lub drugim i trzecim, winny wnieść opłatę w wysokości
800 zł. Opłata dla magistrantów i doktorantów oraz młodych doktorów biorących aktywny udział w Forum Młodych może być zmniejszone do 600 zł, przy zachowaniu takich
samych świadczeń. Osoby te winny dodatkowo dostarczyć: rozszerzone streszczenia
(4-6 stron) swoich wystąpień (do 15.08.2009 r.). Jest także wymagana opinia opiekuna
naukowego. Sprawy te będą rozpatrywane indywidualnie przez Radę Naukową Konferencji. Członkowie Towarzystwa Chemii i Inżynierii Ekologicznej i Polskiego Towarzystwa Chemicznego (z opłaconymi na bieżąco składkami) mają prawo do obniżonej opłaty konferencyjnej o 25 zł. Opłaty wnoszone po 15 września 2009 r. są większe
o 10% od kwot podanych powyżej. Wszystkie wpłaty winne być dokonane na konto
Towarzystwa Chemii i Inżynierii Ekologicznej w Banku Śląskim:
BSK O/Opole Nr 65 1050 1504 1000 0005 0044 3825
i mieć dopisek ECOpole'09 oraz nazwisko uczestnika konferencji.
Prosimy również o zgłoszenie uczestnictwa w konferencji poprzez wypełnienie formularza zgłoszeniowego i przesłanie go mailem, faksem lub pocztą.
Po konferencji zostaną wydane 4-6-stronicowe rozszerzone streszczenia wystąpień
w półroczniku Proceedings of ECOpole. Artykuły te winny być przesłane do 1 października 2009 r. Wszystkie nadsyłane prace podlegają zwykłej procedurze recenzyjnej.
Wszystkie streszczenia oraz program Konferencji zostaną wydane na
CD-ROM-ie, który otrzyma każdy z uczestników podczas rejestracji. Program będzie
także umieszczony na stronie webowej konferencji.
dr hab. inż. Maria Wacławek prof. UO
Przewodnicząca Komitetu Organizacyjnego
Wszelkie uwagi i zapytania można kierować na adres:
[email protected]
lub [email protected]
tel. 077 401 60 42
tel. 077 455 91 49
fax 077 401 60 51
413
Kalendarium dotychczasowych konferencji tej serii:
1. 1992 Monitoring’92 Opole
2. 1993 Monitoring’93 Turawa
3. 1994 Monitoring’94 Pokrzywna
4. 1995 EKO-Opole’95 Turawa
5. 1996 EKO-Opole’96 Kędzierzyn-Koźle
6. 1997 EKO-Opole’97 Duszniki Zdrój
7. 1998 ŚEK ECOpole’98 Kędzierzyn-Koźle
8. 1999 ŚEK ECOpole’99 Duszniki Zdrój
9. 2000 ŚEK ECOpole 2000 Duszniki Zdrój
17. 2008 ŚEK ECOpole’08 Piechowice
414
ZGŁASZAM UCZESTNICTWO W KONFERENCJI ECOpole’09
(prosimy o wypełnienie zgłoszenia drukowanymi literami)
Nazwisko i imię .............................................................................................................
Tytuł (stopień) naukowy/stanowisko .............................................................................
Miejsce pracy ................................................................................................................
Adres .............................................................................................................................
tel./fax ....................................................., email ...........................................................
Dane instytucji (nazwa, adres, NIP), dla której ma być wystawiona faktura:
........................................................................................................................................
........................................................................................................................................
........................................................................................................................................
RODZAJ PRZEWIDYWANEGO WYSTĄPIENIA
TAK
NIE
Referat
Poster
Głos w dyskusji
TYTUŁ WYSTĄPIENIA ............................................................................................
........................................................................................................................................
ZAMAWIAM NOCLEG
14/15 X
15/16 X
TAK
NIE
TAK
ZAMAWIAM POSIŁKI
Data
Śniadanie
14 X
--15 X
16 X
17 X
NIE
Obiad
---
16/17 X
TAK
NIE
Kolacja
---
GUIDE FOR AUTHORS ON SUBMISSION
OF MANUSCRIPTS
A digital version of the Manuscript addressed:
Professor Witold Wacławek
Editor-in-chief
Ecological Chemistry and Engineering (Ecol. Chem. Eng.)
Uniwersytet Opolski
ul. Oleska 48, 45-951 Opole, Poland
tel. +48 77 452 71 34, fax +48 77 455 91 49
should be sent by email to the Editorial Office Secretariat - [email protected]
The Editor assumes, that an author submitting a paper for publication has been authorised to
do that. It is understood the paper submitted to be original and unpublished work, and is not being
considered for publication by another journal. After printing, the copyright of the paper is
transferred to Towarzystwo Chemii i Inżynierii Ekologicznej (Society for Ecological Chemistry
and Engineering). In preparation of the manuscript please follow the general outline of papers
published in the most recent issues of Ecol. Chem. Eng., a sample copy can be sent, if requested.
Papers submitted are supposed to be written in English language and should include a summary
and keywords, if possible also in Polish language. If not then the Polish summary and keywords
will be provided by the Editorial Office. All authors are requested to inform of their current
addresses, phone and fax numbers and their email addresses.
It is urged to follow the units recommended by the Systéme Internationale d'Unites (SI).
Graph axis labels and table captions must include the quantity units.
Symbols recommended by the International Union of Pure and Applied Chemistry (Pure and
Appl. Chem. 1979, 51, 1-41) are to be followed. Graphics (drawings, plots) should also be
supplied in the form of digital vector - type files, eg CorelDraw, Grapher for Windows or at least
in a bitmap format (TIF, JPG, PCX, BMP). In the case of any query please feel free to contact with
the Editorial Office. Footnotes, tables and graphs should be prepared as separate files. References
cited chronologically should follow the examples given below:
[l] Kowalski J. and Malinowski A.: Polish J. Chem., 1990, 40(3), 2080-2085.
[2] Nowak S.: Chemia nieorganiczna. WNT, Warszawa 1990.
Journal titles should preferably follow the Chem. Abst. Service recommended abbreviations.
Receipt of a paper submitted for publication will be acknowledged by email.
If no acknowledgement has been received, please check it with the Editorial Office
by email, fax, letter or phone.
416
ZALECENIA DOTYCZĄCE PRZYGOTOWANIA
MANUSKRYPTÓW
Praca przeznaczona do druku w czasopismach Ecological Chemistry and Engineering S/Chemia
i Inżynieria Ekologiczna S (Ecol. Chem. Eng. S) powinna być przesłana na adres Redakcji:
Profesor Witold Wacławek
Redakcja
Ecological Chemistry and Engineering/Chemia i Inżynieria Ekologiczna
Uniwersytet Opolski
ul. Oleska 48, 45-951 Opole
tel. 77 452 71 34, fax 77 455 91 49
w postaci cyfrowej w formacie Microsoft Word (ver. XP dla Windows) emailem ([email protected])
lub na dyskietce.
Redakcja przyjmuje, że autor, przesyłając artykułu do druku, w ten sposób oświadcza, że jest
upoważniony do tego, oraz zapewnia, że artykuł ten jest oryginalny i nie był
wcześniej drukowany gdzie indziej i nie jest wysłany do druku gdzie indziej oraz że po jego wydrukowaniu copyright do tego artykułu uzyskuje Towarzystwo Chemii i Inżynierii Ekologicznej.
W przygotowaniu manuskryptu należy przede wszystkim wzorować się na postaci artykułów
w możliwie najnowszych zeszytach Ecol. Chem. Eng. Prace przesyłane do publikacji winny być
napisane w języku angielskim lub polskim oraz zaopatrzone w streszczenia oraz słowa kluczowe
w obydwu tych językach. Zalecamy, aby artykuł zawierał adresy i emaile oraz numery telefonów
i faksów wszystkich autorów danej pracy, szczególnie głównego autora, którego nazwisko wyróżniamy gwiazdką.
Usilnie prosimy o stosowanie układu jednostek SI. Zwracamy uwagę, że osie wykresów oraz
główki tabel powinny bezwzględnie zawierać jednostki stosownej wielkości. W przypadku artykułów pisanych po polsku podpisy tabel i rysunków powinny być podane w językach polskim
i angielskim.
Polecamy symbolikę zalecaną przez PTChem (Symbole i terminologia wielkości
i jednostek stosowanych w chemii fizycznej, Ossolineum, Wrocław 1989; Pure Appl. Chem.,
1979, 51, 1-41).
Materiał graficzny (rysunki, wykresy), obok wersji na papierze, powinien również być dostarczony w postaci cyfrowych plików wektorowych, np. za pomocą programów: CorelDraw wersja
9.0, Grafer dla Windows lub przynajmniej bitowe (TIF, JPG, PCX, BMP).
Przypisy i tabele, podobnie jak rysunki, zapisujemy jako osobne pliki.
Literaturę prosimy zamieszczać wg poniższych przykładów:
417
[1] Kowalski J. i Malinowski A.: Polish J. Chem., 1990, 40(3), 2080-2085.
[2] Nowak S.: Chemia nieorganiczna. WNT, Warszawa 1990.
Tytuły czasopism należy skracać zgodnie z zasadami przyjętymi przez amerykańską Chemical
Abstracts Service, a w przypadku polskich publikacji niepodawanych przez CAS należy stosować
skrót zgodnie z zaleceniami Biblioteki Narodowej. Autor może, jeżeli uważa to za wskazane,
podawać też tytuł cytowanych artykułów z czasopism (który będzie składany kursywą) oraz numer
zeszytu danego woluminu (w nawiasie, po numerze woluminu).
Redakcja potwierdza emailem otrzymanie artykułu do druku. W przypadku braku potwierdzenia prosimy o interwencję: emailem, faksem, listem lub telefonicznie.
PRZYGOTOWANIE DO DRUKU
Zdzisława Tasarz
Lucyna Żyła
Aleksander Zaremba
PROJEKT OKŁADKI
Marian Wojewoda
Druk: „Drukarnia Smolarski”, Józef Smolarski
ul. Ozimska 182, 45-310 Opole
Objętość: ark. wyd. 13,7, ark. druk. 10,25

Volume 16, Issue 3 (Sep 2009) - Society of Ecological Chemistry

Transkrypt

Podobne dokumenty

Prawna obsługa biznesu Legal services to business

DEMO PDF angielski do sluchania czasowniki

Laboratorium z inżynierii mikrofalowej

A new method of spectrophotometric determination of poly