The results of a model laboratory experiment in which the acidic oil-polluted sand was incubated for three months in the presence of palygorskite or bentonite clays supplemented with mineral fertilizers and lime under conditions of periodic wetting and drying are presented. A reliable decrease in the total content of nonpolar and weakly polar CCl 4 extractable organic compounds and of the weakly polar compounds was established. The content of the nonpolar fraction, the amount of C 14 –C 36 alkanes in its composition, and the (C 17 + C 18 )/(C i –15 + C i –16 ) ratio, which was indicative of microbiological destruction of hydrocarbons, decreased significantly in the experiment with the palygorskite clay.

A field model experiment on stimulating the activity of native oil microorganisms–decomposers was performed on an oil-polluted area in a high-moor bog under its total flooding in the northern taiga (Western Siberia). For two summer months, the doses of lime and nitrogen, phosphorus, and potassium fertilizers applied have caused a decrease in the oil products (OP) content by 54% relative to their initial amount. The decrease of the OP content in the soil profiles was nonuniform, and at the depth of 30–50 cm it was accompanied by the acidification of peat. The stimulation of the activity of aboriginal microorganisms by applying lime and mineral fertilizers led to the development of migration processes with the participation of oil and products of its transformation. These processes differed from those in the soil without application of lime and fertilizers. An original technology of applying lime and fertilizers providing minimal disturbances the upper 50-cm peat layer is suggested.

The experimental data, obtained in the experiments on adsorption of Arsenic (As) by various soils and minerals and fraction of formed As species in natural and polluted soils, are discussed. They reflect general laws of formation of microelements species in soils, and specific features of the element. The influence of soil (hydr) oxides of Aluminium (Al) and Iron(Fe) is estimated for the formation of As-species in soils. The composition of As species reflects the influence of all soil-forming factors. At the same time, it serves as the indicator of ecological state of a landscape since soil species of an element define all kinds of its migration.

The schemes for fractionation of soil microelement compounds were analyzed. A scheme of extracting As compounds that are sorbed specifically and nonspecifically and bound with oxides (hydroxides) of Fe, Al, Mn, organic matter, carbonates, and soil minerals is proposed. The scheme differs from the existing ones in the higher selectivity of extracting the fractions due to changes in the combination of the extractants and the sequence of their use.