Method for on site cleaning of soil contaminated with metal compounds,

Abstract

An in situ method of cleaning soil and/or water contaminated with a contaminant comprising one or more compounds selected from the group consisting of metal compounds, sulfur compounds and cyanide compounds comprises breaking up contaminated soil, admixing soil with water and a biodegradable detergent in a proportion effective to obtain an aqueous slurry where the soil, any contaminant and the detergent interact to form contaminant-detergent formations, allowing the slurry to stand under conditions effective to permit any contaminant-detergent formations to rise in the aqueous slurry, separating the contaminant-detergent formations from the aqueous slurry now comprising partially decontaminated soil and water, separating the soil from the water, repeating the cleaning and separation steps until the soil has less contaminant than a predetermined value, typically a 80-90% decrease, admixing the soil having a lower contamination level with water and an activating agent for microorganisms capable of removing the contaminants, the agent being capable of generating H.sub.2 O.sub.2 in solution, allowing the activating agent to interact with the soil microorganisms in the aqueous mixture under conditions effective to further remove contaminants remaining therein, separating the activating agent-treated soil from the aqueous mixture comprising the microorganisms, washing the separated soil and returning it to the original site, separating the contaminated water from the decontaminant laden microorganisms, and recycling the decontamined water into the system or returning it to the environment.