George DUCA, academician

PhD in chemistry, university professor
president of the Academy of Sciences of Moldova

Republic of Moldova
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ECOLOGICAL CHEMISTRY

Tue, 08/02/2016 - 14:56

Ecological Chemistry is the science dealing with the study of processes which determine the composition, structure and chemical properties of the environmental objects, adequate to the biological value of habitats [1]. According to another definition, Ecological Chemistry is a science of the chemical processes and interactions in the natural environment (ecosphere), as well as of such interactions’ consequences [2].

Ecological Chemistry is closely linked with the other research disciplines, first of all with the Physical Chemistry (dealing with the studies of substances mass-transfer in the environment), Chemical Kinetics (pollutants transformation mechanisms), Analytical Chemistry (physical-chemical methods of analysis) and Biochemistry (molecular mechanisms of pollutants impacts on the vital activity processes). Ecological Chemistry involves the compartments of these disciplines, related to the nature protection topics, and at the same time possesses its own features, being a complex science investigating the chemical processes in the environment. It is called to describe the dynamics of eco-chemical processes in the environmental objects, as well as in the artificial eco-systems, to prognosticate and regulate the ecological consequences of anthropogenic impacts on the natural environment. In a broader scale, Ecological Chemistry id connected with such research areas as biology, medicine, meteorology, Earth sciences, agricultural chemistry, soil science, geology, pharmacology, etc.

The scope of the Ecological Chemistry is the study of substance’s transformations in the environment and prognostication of their consequences. Therefore, the various research methods are used here, including the kinetic, analytical, chemical-biological, microbiological and ecological ones.

On the base of Ecological Chemistry lies the study of the processes running in the environment, under their chemical aspect, considering the anthropogenic impacts on both the biotic and abiotic components of the environment. The biotic component of the natural environment (flora and fauna) – biota – and the surrounding external environment are in the state of the dynamic eco-chemical equilibrium. The biological indicators of the habitat validity are thus the species diversity and ecosystem’s bioproductivity, compared to the ecosystems, which are not subjected to the anthropogenic impacts. The condition of the external habitat can be assessed by the totality of physical and chemical parameters. Under the anthropogenic impacts, the modification of both physical parameters (temperature, exposure to sun, mass-transfer, etc.) can occur, and that of the chemical composition of environment.

The specifics of a nowadays situation is that the changes which take place in the environment occur more rapidly than the control and prognostication methods are developing. Ecological Chemistry provides a qualitatively new approach towards the description of the condition of environment as a dynamic chemical-biological system.

A chemical act, representing the transformation of the initial substances into the products, lays on the basis of vital activity processes. Any chemical-biological process is a totality of chemical acts, determining the process mechanism. So, in order to describe and control the dynamically equilibrium state of ecosystems under the increasing scale of human activity, it is necessary to learn the interaction mechanisms between the man, environment/habitat and ecological sub-systems.

The biological aspect of such interaction is a subject of the Chemical Ecology – a science of the chemical interactions between the living organisms or between the live and mineral nature. Unlike the Ecological Chemistry, Chemical Ecology is limited by the study of natural materials, use of the substances only under the natural conditions, research of the exchange processes and regulation mechanisms in the organisms. In the Ecological Chemistry, along with the biological methods, the chemical ones are applied as well, mainly to study qualitative and quantitative composition of chemical pollutants and their transformations in the environment. The chemicals’ “ecological behaviour” and transformation is thus depending on both their molecular structure and the properties of the environment itself.

The notions “Chemical Ecology” and “Ecological Chemistry” underline the link between the Chemistry and Ecology. At the same time, each of these sciences is a system of research disciplines. Ecology, the science dealing with the regularities of the organisms’ interactions and interrelations with each other and with the habitats, has transformed to the science which studies the structure of nature. Chemistry being the science dealing with the substances, their structure and transformations, describes the nature components composition and properties on the atomic-molecular level.

Ecotoxicology is dealing with the research of the anthropogenic chemicals effect on the biological objects. Its task is to study the effects of the chemical factors on the species, living communities, abiotic components of ecosystems and their functions. It differs from the Toxicology by the fact that the problems of the specific organism poisoning are not considered here.

The main research directions in Ecological Chemistry involve:

- elaboration of recommendations on the reducing of the chemical pollution level of the environment with the most dangerous substances;

- improvement of technologic processes of raw materials processing, wastes utilization, treatment of gas emissions and waste waters;

- prognostication of chemical pollutants behaviour in the environment under the influence of natural and anthropogenic factors;

- elaboration of the control methods over the state of the environmental objects pollution.

In practical aspect, three main tasks of Ecological Chemistry can be outlined, which resolving determines the safety of the habitat.

I. The modification of the existing technological processes, aimed at the reducing of energy and resource consumption, minimizing of the emissions in atmosphere and hydrosphere, i.e. the development of a new and improvement of the available technologies, considering the environmental protection requirements.

This task can be resolved by several ways at the same time: engineering-organizational (complex use of the feedstock, wastes-free production cycle, closed-cycle water supply systems, etc.), and chemical-technological ones (increase of the processes selectivity and regimes optimization, carrying out the reactions under the soft conditions, elaboration of new catalysts, substitution of certain process stages with the ecologically pure ones, etc.).

There is no doubt that all the chemicals produced, sold or used in the households or by the industries, will finally occur in the environment. While implementing the advanced technology (eco-technology) or flow-sheet, the use of such materials and products should be promoted, which global accumulation will not bring the harmful consequences for the entire ecosphere, which part is a man. It is the task of Ecological Chemistry to develop the selection criteria for such chemicals.

II. Treatment of gas emissions into the atmosphere and the wastewaters from the most toxic substances. These issues are closely connected with the production economy: the treatment costs depend on the required treatment level. This is related both to the local treatment of a separate industries’ emissions, and the treatment of a municipal wastewaters, management of solid and liquid wastes. There is, however, a specific treatment level, determined by the economy of the production. The exceeding of this level means that the overall production cycle becomes economically unprofitable. Therefore, there is a need to improve the efficiency of treatment plants, simultaneously with the treatment costs reducing. We need to mention, that the capabilities of Chemistry are still significant with this regard, and the possibilities are not exhausted here.

III. Assessment of the pollutants impacts on the environment. There are two aspects: on one hand, the toxicity problem of the pollutants incoming the environment; and on the other hand, migration and transformation of substance under the influence of the natural factors. The role of ecological chemistry is to give an assessment of the pollutants transformation rate in dependence of the natural factors. To forecast the pollutants behaviour in the environmental compartments and objects, the kinetic parameters can be used in the mathematical models.

The research of the interrelations between the chemical products, living and mineral components of the ecosphere implies the revealing of the pollution of the environment, its decrease and its eventual consequences. The study of the environment pollution involves the following stages:

- chemical contents in the environment and its produced amounts;

- fields of application;

- spreading in the environment;

- income and accumulation in the environment;

- ecotoxicity and toxicity;

- persistence and destructivity;

- further transformation reactions.

Ecological Chemistry, being a relatively new science, has received especially rapid development in the last 20-30 years, starting from the 80-ies of the XXth century. Until its appearance, there was no scientific discipline capable to elaborate the bases of the chemicals classification and to justify the research of the anthropogenic impacts on the biosphere. Nowadays in many countries, including the USA, Germany, Poland, Russia, Moldova, etc., there are the research centers and scientific schools on Ecological Chemistry, headed by the outstanding scientists in this field. Among the founders of Ecdological Chemistry can be named J.Bockris, A.P.Purmal, A.Ya.Sychev, Gh.Duca, F.Korte, M.Bahadir, V.Klein, Yu.I.Skurlatov and others.

In addition to the manuals and monographs devoted to the Ecological Chemistry [1-7], a series of research papers [8], periodicals and specialized journals in this area are published as well, among them: Ecological Chemistry and Engineering S, Environmental Chemistry Letters, Environmental Chemistry, etc.

Prof.Yu.I.Skurlatov, Head of the Laboratory of Hydroecochemical Processes, working for many years at the N.N.Semenov Institute of Chemical Physics of Russian Academy of Sciences (RAS), has become one of the main scientists focused its research efforts on the environment protection topics. He is author of many publications and monographs [1] in the field of ecological chemistry, whereas his research team is currently doing the fundamental research in the field of ecotoxicants risk systematization and assessment, which may pose a risk for the environment, study the forms of existence, migration and transformations of ecotoxicants in the environmental compartments and bodies, issues of ecotoxicants transboundary transfer, etc. An important research direction of the scientists from this Institute is elaboration of physical-chemical methods of active counteraction to toxic pollutions, their removal and neutralization, elaboration of the concept and methodology of consequences liquidation, connected with the anthropogenic and technogenic pollutions in the ecological tension zones, development and testing of non-traditional methods of the environment compartments treatment, etc.

There is a research school on Ecological Chemistry in the Republic of Moldova, working and developing for many years already, headed by Acad. Prof. Gh.Duca. By his initiative, in 1992, the Department of Industriual and Ecological has been established at the Chemical Faculty of the State University of Moldova (SUM); however, the research in this area has started even earlier, in the frames of the Department of Physical Chemistry of the same uiversity.

The research staff of the Department, as well as that of the Research Center of Applied and Ecological Chemistry established two years later, are dealing with the broad spectrum of research problems: oxidation-reduction processes in the natural water environment, oxidation and reduction mechanisms in the water bodies quality formation, natural waters self-purification issues, toxic substances transformations in the environment and some foodstuffs and their impacts on the human organism, treatment of agro-industrial and communal wastewaters, purification of air emissions from pollutants, sludge and wastes management. Specifically, a special interest for the wine-production industry is the study of the redox-catalytical oxidation of polyphenols to tartaric acid, elaboration of novel technologies and reactors for the winery wastes neutralization and obtaining of a series of useful products on their base, obtaining of ne substances and preparations of medicinal interest from natural raw materials, etc.

The Department of Industrial and Ecological Chemistry has become an initiator and organizer of a series of successful international scientific events on Ecological Chemistry, held in Chisinau, Republic of Moldova: Ist Intl. Symp. On Ecological Chemistry (October 1-4, 1995); IInd Intl. Conf. on Ecological Chemistry (October 11-12, 2002); IIIrd Intl. Conf. on Ecological Chemistry (May 20-21, 2005); IVth Intl. Conf. on Ecological Chemistry (November 12-15, 2008) and Vth Intl. Conf. on Ecological Chemistry (March 2-3, 2012).

A series of the directions of Ecological Chemistry has become the research subject for the scientists from the Laboratory of Ecological Chemistry of the Institute of Chemistry of the Academy of Sciences of Moldova (ASM), established as early as 1962 under the name of the Laboratory of Raw Materials. The school of Ecological Chemistry under the guidance of Prof.T.Lupascu, cor.mem of ASM, is dealing with the elaboration of the environment-protecting technologies, including the methods of active carbons preparation and mineral sorbents activation [9], study of the pollutants sorption mechanisms on them, study of the pollutants migration and transformation mechanisms in natural water bodies [10], elaboration of methods and technological processes for natural and waste waters treatment, utilization of agricultural by-products and some other processes. The specifics of this research is their, along with the theoretical, a practical value, which made it possible for the scientists to recommend for practical applications and test the new adsorption processes for water treatment, to elaborate a series of useful preparations based on the “Enoxil” – ecologically pure product and active substance with the enhanced antibacterial properties [11] as well as the other processes.

References:

  1. Skurlatov, Yu.I., Duca, Gh.G., Misiti, А. (1994). Introduction in Ecological Chemistry: Manual for chem. and chem.-tech. univ. М.: Vyshaia Shkola. - 400 p. (Rus.). - ISBN 5-06-002593-4.
  2. Korte, F., Bahadir, М., Klein, V. et al. (1997). Ecological Chemistry. Transl. from German. Basics and Concepts. /Ed. F. Korte. М.: Mir. - 396 p. (Rus.transl.). ISBN 5-03-003081-6; ISBN 3-13-586703-X.
  3. Giddings, J.C. (1973). Chemistry, Man and Environmental Change, Canfield Press, San Francisco.
  4. Duca, Gh. (2012). Dicţionar poliglot de chimie ecologică. Chisinau: Inst. de Studii Enciclopedice. - 680 p. - ISBN 978-9975-4307-1-5.
  5. The Role of Ecological Chemistry in Pollution Research and Sustainable Development : Proc. of the NATO Advanced Research Workshop, Chisinau, Moldova, 8-11 October 2008 / ed. by Ali Müfit Bahadir, Gheorghe Duca. – Dordrecht : Springer, 2009. – 308 p. – (NATO Science for Peace and Security Ser. C: Environmental Security). – ISBN 978-90-481-2901-0 (Print) 978-90-481-2903-4 (Online). –http://www.springerlink.com/content/978-90-481-2901-0?v=editorial
  6. Duca, Gh., Skurlatov, Yu., Misiti, A., Macoveanu, M. et al. (2003). Chimie Ecologica (Rom.). 2nd Ed. Chisinau: CE USM, 303 p.
  7. Gonta, M., Duca, Gh. (2009). “Chimia ecologica a nitratilor, nitritilor si N-nitrozoaminelor” (Rom.). Chisinau, CEP USM. – 268 p.
  8. Gh. Duca. Chemistry vs Ecology. Chemistry Journal of Moldova: General, Industrial and Ecological Chemistry. 2012, Vol. 7, Nr 1, p. 12-19.
  9. Lupascu, T. (2004).  Cărbuni activi din materii prime vegetale. (Rom.). Chişinău: ÎEP Ştiinţa. -  224 p.
  10. Rusu, V., Lupascu, T. (2004). Chimia sedimentelor sistemelor acvatice. Proprietăţi de suprafaţă. Modele fizico-chimice (Rom.). Chişinău: Ed. Elena V.I. - 272 p.
  11. Lupascu, T., Duca, Gh., Rudic, V. et al. (2012). Enoxil - preparat ecologic pentru sănătatea omului. (Rom.) Chisinau : Ed. Acad. de Ştiinţe a Moldovei. - 256 p. - ISBN 978-9975-62-304-9.

DEFINITIONS

Ecological Chemistry is the science dealing with the study of processes which determine the composition, structure and chemical properties of the environmental objects, adequate to the biological value of habitats [1]. According to another definition, Ecological Chemistry is a science of the chemical processes and interactions in the natural environment (ecosphere), as well as of such interactions’ consequences [2].

Chimia Ecologică este ştiinţa care stuază procesele ce determină compăoziţia, strctura şi proprietăţile chimice ale obiectelor din mediul ambient, adecvate de valoare biologică a habitatelor [1]. Conform unei alte definiţii, Chimia Ecologică este ştiinţa ce ţine de procese chimice şi interacţinile în mediul ambient (ecosfera), precum şi de consecinţele acestor interacţiuni [2].

Экологическая химия - это наука, изучающая процессы, определяющие состав, структуру и химические свойства объектов окружающей среды, соответствующие биологической ценности среды обитания [1]. Согласно другому определению, Экологическая Химия это наука о химических процессах и взаимодействиях в природной среде (экосфере), а также о последствиях таких взаимодействий [2].