Bioremediation of hydrocarbon-impacted soils is a well-establish technology which has been effectively applied to the landfarming of contaminated soils, drill cutting, and tank bottoms. The efficiency of the process is increased by reducing initial hydrocarbon loading rates by blending with clean topsoil. However, blending in clean topsoil increases cost and results in higher volumes of treated soil that must be disposed of when treatment is complete. Increasing hydrocarbon loading rates above 4-6 wt% during bioremediation typically results in increased hydrophobicity, limiting water wetting and thus also inhibiting availability of nutrients and air to the microorganisms. The practical result are hydrocarbon concentrations at the bioremediation endpoint that are too high to meet disposal criteria. In this paper we describe the biotreatment of drill cuttings with initial hydrocarbon loadings of 9 wt% followed by treatment with calcium peroxide/hydrogen peroxide to drive hydrocarbon concentrations low enough for disposal.
Christian J. Elliott
Ohio Soil Recycling
Kerry L. Sublette, The University of Tulsa, Tulsa, OK