Moklyachuk L. Scientific and methodological basis of Ecotoxicological monitoring and remediation of soil polluted by organic xenobiotics

In dissertation scientific - methodical basis of ecotoxicological monitoring of soil polluted by organic xenobiotics which is a component of agroecological monitoring system are theoretically proved and developed. The result of ecotoxicological monitoring is determination of revealing zones polluted by persistent organic substances and development of ecologically safe methods of remediation of polluted soils. Ecotoxicological monitoring of organic xenobiotics is carried out in the following directions: crisis monitoring ( revealing and agroecological estimation of zones polluted by persistent organic substances); POPs monitoring of farmland soils with the purpose of organic agriculture implementation; and monitoring of quantity of pesticides allowed for application in soils and agricultural products for the prevention of threat of toxicants' uptake in human organism. Scientific - methodical basis are developed and local crisis monitoring of the soils of the sites polluted by persistent pesticides in conditions of various natural-climatic zones is carried out. In particular, it's dealing with crisis monitoring of a transitive zone between Polissya and Forest-steppe; Forest zone; Steppes zone; and transitive zone between Forest-steppe and Foothill zones. It is established that soils of sanitary zones of pesticides warehouses are dangerous source of environmental contamination by persistent organochlorine pesticides. Within the framework of program АЕМ of the Institute of Agroecology the ecotoxicological soil estimation of POPs contents (including obsolete organochlorine pesticides - DDT and HCH) of some territories is carried out. There are Boguslav range in the Kiev region and experimental fields of Scientifically - methodical Centre "Agroecology". It is shown, that metabolic content of DDT (a ratio: 4,4'-DDT:4,4'-DDЕ:4,4'-DDD) in the farmland soils and brise is submitted basically by the most persistent metabolite 4,4 '-DDЕ. That is evidence of (testifies) of old pollution of soils by these pesticides and prevalence of aerobic passage of pesticide degradation reactions. Process of acetochlor migration during the cultivation of corn as monoculture is investigated. The danger process of accumulation of pesticide in soil horizons and its receipt in water sources during the 8-annual application of acetochlor on the same areas is showed. The way of anaerobic bioremediation of soil with old pollution of organochlorine pesticides is developed. This bioremediation is based on the increasing of bioavailability of organochlorine pesticides for microorganisms under influence of carbonic agents (Са, Са(OH)2, СаСО3) with formation of nontoxic substances. It is established, that for neutralization of organochlorine pesticides it is necessary to use the carbonates in quantities of 2 % from soil weight. It is revealed, that in the polluted zones there is a significant depression of ferment soil activity. In chernozem soil peroxidazes activity (EC1.11.1.7) in relation to the control decreases in 1,6 times, polyphenoleoxidaze activity (EC 1.10.3.1) - in 2,5 times; in dernovopodzolic soil - peroxidaze activity decreases in 1,9 times; polyphenoleoxidaze activity - in 3 times. In process of soil bioremediation there is an increasing of activity of both ferments: peroxidaze and polyphenoleoxidaze. These ferments catalyze redox processes of pesticides destruction almost in 2 times. Hence, parameters of activity of oxidoreductaze ferments can serve as the bioindicators of soil pollution by organochlorine pesticides. It is shown, that under influence of a long-term working polycomponenal pollution of soil by the pesticides, remainders of pesticides and their metabolites are formed specific microbiocenoze. Microorganisms which keep viability in conditions of long-term influences of pesticides are potentially capable to biodegradation of DDT. Scientific - methodical approaches to remediation of soils polluted by pesticides are developed. Dealing with amplification of phytotechnologies the prime attention should begiven on phytotoxical estimation of soil parameters of a researched for high plants. For dernovopodzolic soil with old pesticides pollution it was observed the slowed down toxic effect, which is shown in terms, which exceed recommended 14-21 days by ISO 11269-1,2:2004. Probably this effect is possible to explain by the process of adsorption of toxicants remains on the surface of soil's particles, that considerably reduces their biocapability. For phytotoxical to cultural plants' soils the searching of plants - phytoremediators among local plants which were tolerant to pesticides is carried out. This monitoring was based on such parameters as the structure of phytocenose; quantitative and qualitative ratio of varieties and families of local plants; and accumulative capability of plants to pesticides.