Compost decontamination of DDT contaminated soil
AssigneeZeneca Limited
InventorsRoger L. Bernier, Neil C. C. Gray, Lori E. Moser
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Abstract
The present invention provides a process of decontaminating soil and/or sediments containing DDT type contaminants by converting these contaminants into harmless materials thereby decontaminating the soil to whatever extent desired, either partial decontamiation or complete remediation. The process comprises treating solid and/or sediment which contains populations of viable anaerobic and aerobic microbes capable of transforming DDT type contaminants into harmless materials and being viable under both anaerobic and aerobic conditions.
Claims24
The process of decontamination of soil containing DDT type contaminants which soil contains populations of viable anaerobic and aerobic microbes capable of transforming DDT type contaminants into harmless materials and being viable under both anaerobic and aerobic conditions comprising:
- (a) admixing said soil with amendment material to form a solid compost mixture containing organic nutrient materials;
- (b) composting said soil while maintaining the temperature of the compost mixture in the range of about 20.degree. C. to 65.degree. C. and the water content of the compost mixture in the range of about 40% to 100% WHC;
- (c) during said composting maintaining the redox potential level of the compost mixture below about negative 200 mV until a significant amount of DDT type contaminants is degraded;
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- (d) thereafter oxygenating the compost mixture to raise the redox potential level of the compost mixture to above about positive 100 mV, and maintaining the redox potential level above about positive 100 until a significant amount of DDT type contaminants is degraded.
The process of decontamination of soil containing DDT type contaminants which soil contains populations of viable anaerobic and aerobic microbes capable of transforming DDT type contaminants into harmless materials and being viable under both anaerobic and aerobic conditions comprising:
- (a) admixing said soil with amendment material comprising agricultural waste or municipal waste sludge to form a solid compost mixture containing organic nutrient materials wherein said compost mixture contains at least about 10% by weight of amendment material;
- (b) composting said soil while maintaining the temperature of the compost mixture in the range of about 20.degree. C. to 65.degree. C. and the water content of the compost mixture in the range of about 40% to 100% WHC;
- (c) during said composting maintaining the redox potential level of the compost mixture below about negative 200 mV until a significant amount of DDT type contaminants is degraded;
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- (d) thereafter oxygenating the compost mixture to raise the redox potential level of the compost mixture to above about positive 100 mV, and maintaining the redox potential level above about positive 100 until a significant amount of DDT type contaminants is degraded.
Dependencies are inferred from the claim text.