Supertoxicants: modeling of their formation and distribution caused by the oil spills on the objects of production and transportation of oil

Abstract

Summary The accidental oil spills are still one of the mostly serious problems in the Russian oil and gas complexes. But until today the approaches to the analyses of the consequences of oil spills can not be recognized as adequate, as well as the approaches to the planning and preparation to the localization and elimination of possible accidents. One of the reasons of this situation is underestimation of danger of the oil components and of the processes of their migration and transformation. In the process of the geoecological estimation the main attention is mostly paid to the total concentrations of oil products, without considering the processes of the natural fractioning. The consequence of such approach is that the toxic properties of the oil components (incl. polycyclic aromatic hydrocarbons (PAH) and others supertoxicants) are underestimated, the environmental damages are undervaluated, the migration of hydrocarbons in the system "soil – atmosphere – grounds – plants" is inaccurate. The oil transformation products include persistent organic compounds – the individual group of xenobiotics, which main properties are toxicity, perstistence, high migration ability and cumulativeness. The existing equations of hydrocarbons balance suggest the vertical migration of oil products with the moisture flow in the system "soils – subsoils – capillary zone – zone of saturation". But it doesn't taking into account that the phase transitions of substances are caused by the dominant processes: atmosphere – evaporation and chemical oxidation in soils – biooxidation and biodistruction; in grounds – sorption, diffusion; in capillary zone – formation of entrapped forms of hydrocarbons; in the zone of saturation – spreading of the lens and migration inside as a dissolved form. The age of the oil pollution, the anisotropy of the pollutants movement and their type are very important. It is necessary to develop the system of the reliable indicators of landscapes' state, taking into account the transformation of oil products and building of the new compounds with the natural substrates, with the estimation of their toxicity and lifetime in the environment. The multicomponent model of oil products migration with selection of the determined forms of transformation processes is proposed. The 4-zone structure of the upper part of section with oil products' forms and indicators of individual substances as well as natural fractioning processes is modeling. The geochemical markers are proposed – the final products of oxidation and biodestruction, diffusion and sorption of oil components in the environments. The proposed solutions are necessary to use in the monitoring praxis, as well as for the selection of priority directions of remediation of the damaged landscapes. Considering the necessity of improvement of landscapes remediation efficiency, these studies are very promising.