TRANSFORMATION OF OIL PRODUCTS IN THE SOILS OF THE VOLGOGRAD AGGLOMERATION
The anthropogenic centres responsible for soil contamination in the urban landscapes of the Volgograd agglomeration include chemical and metallurgical enterprises, filling stations, transit highways, railway networks, etc. An objective assessment of soil contamination with oil products requires that the presence of natural organic compounds in the soil be taken into account. Leaching of oil products from light chestnut soils occurs during the first 11 days irrespective of the granulometric soil composition and oil product concentration, with the efficiency of the process decreasing by 2.58 times (from 5.29 to 2.05) and 13.9 times (from 69.00 to 4.92%) in clay and sandy soils, respectively. The amount of organic carbon evaporated from clay soils is maximal on the 2nd and 6th days. The depth of penetration of oil products into the soil profile depends upon the granulometric soil composition. The content of oil products having passed into the water extract depends neither on their concentration, nor on the soil type or granulometric composition. Following autoclaving, under the influence of temperature and pressure, the process of thermal desorption and chemical bond destruction is likely to release organic components from clay and hummock complexes. As a result of thermal desorption, the content of oil products in alluvial soils increases.