Effect of a preliminary physicochemical treatment of bituminous crusts resulting from oil pollution on the bioremediation of upland swamps with oil decomposers

Abstract

Physicochemical preprocessing of a bituminous crust resulting from oil pollution by various reagents capable of hydrolyzing its structure, followed by aerobic degradation of hydrocarbons (HC) with the Rhoder bacterial oil-degrading preparation, was carried out. The crust was hydrolyzed with hydrogen dioxide, calcium hydroxide, and alkaline hydrolysate of crop production waste in concentrations from 2 to 20%. The best results in the destruction of the bituminous crust were obtained for processing the upper layer (0−2 cm) of the soil with calcium hydroxide, which resulted in an increase of the humidity of the hydrolyzed layer from 24 to 77%. The destruction of the bituminous crust with chemical agents made it possible to increase the effectiveness of biodegradation of HC from 9.97 to 26.40% in the upper soil layer and from 0.00 to 48.20% in the bottom soil layer. The kinetic characteristics of biodegradation after preprocessing, namely the rate constants of degradation and half-lives of HC were determined, the maximum values of which were found to be 0.015 day−1 and 47 days and 0.032 day−1 and 22 days for the upper and bottom soil layers, respectively.