Remediation of Soils Polluted by Oil Industries

Due to the global problem of soil pollution by oil industry, the development of effective and low-cost methods for soil remediation is highly actual. This chapter reviews the main ecological problems of oil industry and developed methods for remediation of the oil-polluted soils, including nonbiological and biological methods with a focus on bioremediation approaches. Until recently, most studies were concentrated on developing methods for accelerating bioremediation of oil-polluted soils through bioaugmentation and creating optimal conditions for activation of the inoculated microbial strains in the soil. For these purposes, numerous biopreparations have been developed, which are based on exogenous hydrocarbon-oxidizing microorganisms in the form of free or immobilized cells. To increase the bioavailability of low-available petroleum fractions, biosurfactants were used. Meantime, in recent years, the method of adsorptive bioremediation has been suggested, which is able to accelerate the petroleum degradation rate in highly contaminated soils by reducing their toxicity as a result of predominantly reversible sorption of petroleum hydrocarbons and their metabolites. This method may be applied in situ due to a minimal risk of leaching toxic compounds into groundwater. The ecological and economic efficiency of the method has been proven for the polluted soils at the level up to 15% crude oil or diesel oil.