Effectiveness of biogeosorbents based on mineral carriers for treatment oil-contaminated soil

Abstract

Methods for cleaning oil-contaminated areas include the use of sorbents, the effectiveness of which is enhanced by the immobilization of hydrocarbon-oxidizing microorganisms on their surface. Biogeosorbents are obtained on the basis of mineral raw materials (analcime- and glauconite-containing rocks and thermally activated vermiculite) and hydrocarbon-oxidizing bacteria of the genera Pseudomonas and Microbacterium extracted from contaminated soils of the Murmansk region. The number of immobilized bacteria on the studied carriers remains high throughout 9 months of storage, and the bacterial film on the surface of mineral carriers persists for 12 months of storage in an air-dry state. When storing biogeosorbents, no special conditions or additional preparation are required before use. Mineral carriers have a stimulating effect on the height of seedlings and the length of roots of test plants. When biogeosorbents are added, the number of bacteria capable of microbiological transformation of petroleum products increases, and the degree of soil purification from petroleum hydrocarbons at the initial stage (during the first 30 days) increases. The most effective is the introduction of thermally activated vermiculite and glauconite-containing rock with immobilized hydrocarbon-oxidizing bacteria. The use of a biogeosorbent based on thermally activated vermiculite can reduce the cleaning time to 20–22 months, and based on glauconite-containing rock – up to 17 months, while without treatment this period will be at least 29 months.