Accelerated biodegradation of petroleum hydrocarbon waste.
Conventional landfarming approaches to bioremediation of refinery and other petroleum sludges are not acceptable environmentally and are banned in most North American jurisdictions. While initial bioreactor-based systems for treatment of these sludges required batch-cycle process-times of 1-3 months, an accelerated process has now been developed which can be completed in 10-12 days. In this process, up to 99% of total petroleum hydrocarbons are degraded and the sludges are converted from hazardous to non-hazardous according to the United States EPA's toxicity characteristic leachate procedure criteria. Understanding and exploiting mechanisms to improve hydrocarbon accession to the degrading microorganisms was a key development component of the process. Contrasting physiological mechanisms were observed for different component organisms of the mixed culture with respect to their associations with the hydrocarbon substrate; and the beneficial effects of using surfactants were demonstrated. The mixed culture used in the process exhibited a capacity for high-rate degradation of volatile organic carbons and the potential use of the culture as a liquid biofilter was demonstrated. The culture was also effective as an inoculant for the bioaugmentation of total petroleum hydrocarbon-contaminated soil and as a de-emulsifier of oilfield emulsions and could transform some other environmental contaminants which are not predominant components of crude oil.
Ward
Owen
O
Department of Biology, University of Waterloo, N2L 3G1, Waterloo, Ontario, Canada.opward@sciborg.uwaterloo.ca
Singh
Ajay
A
Van Hamme
J
J
D001673:Biodegradation, Environmental; D019149:Bioreactors; D006838:Hydrocarbons / Q000378:metabolism*; D007220:Industrial Waste; D010578:Petroleum / Q000378:metabolism*; D013501:Surface-Active Agents
D006838:Hydrocarbons; D007220:Industrial Waste; D010578:Petroleum; D013501:Surface-Active Agents