Patent ID: 6033899
Filing Date: 2000-03-07
Classification: B09C,Y10S

Abstract:
A process of decontaminating soil containing pentachlorophenol (PCP) contaminant and populations of viable anaerobic and aerobic microbes capable of transforming said contaminant into harmless material, said process comprising:(a) admixing organic nutrient material for composting into said soil, in an amount of at least 10% and up to 95% by weight of the resultant mixture of said soil and said organic nutrient material to form a solid compost mixture;(b) composting said compost mixture while maintaining the temperature of the compost mixture in the range of about 20 to 65 degrees celsius and maintaining water content of the compost mixture in the range of about 40% to 100% of water holding capacity of said compost mixture;(c) during said composting maintaining the redox potential level of the mixture below about negative 200 mV until said contaminant is partially degraded; and(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 at above about positive 100 mV until said contaminant is further degraded;(e) wherein the steps (a) to (d) are repeated until the amount of said contaminant is less than 140 ppm per ton of soil.