Method for biologically detoxifying hexavalent chromium in contaminated soil

Abstract

The invention provides a method for biologically detoxifying hexavalent chromium in contaminated soil. The method is that the contaminated soil is closely piled up by a geomembrane, the primary humidity of the piled-up soil is 60%-85%, the closed soil is not replenished with water, a soil anaerobic condition is generated in the closed system, so that methane is generated, microorganisms generate an anaerobic atmosphere, wherein hydrogen sulfide in the methane or organic acid during the methane production process can react with hexavalent chromium in the soil, so that the hexavalent chromium is reduced to trivalent chromium, and depending on the uniform dispersion of the reduced gas after the long-term contaminant piling and moisture cycle which is generated by temperature difference between day and night, the hexavalent chromium is completely reduced and the soil is detoxified. Depending on the uniform dispersion of the reduced gas after the long-term contaminant piling and moisture cycle which is generated by temperature difference between day and night, the hexavalent chromium can be completely reduced and the soil can be detoxified, no other materials are needed, the process issimple and the treatment cost is low.

Description

technical field [0001] The invention relates to a method for biological detoxification of hexavalent chromium in polluted soil, belonging to the technical field of biological detoxification of hexavalent chromium. Background technique [0002] Chromium is one of the important heavy metal elements in production and life. It has attracted much attention due to its easy migration of hexavalent chromium in soil and water and high biological toxicity. The existing processes for removing hexavalent chromium are all based on the reduction and detoxification mechanism of hexavalent chromium. [0003] Chinese patent document CN2007100492538 discloses a "method for detoxifying chromium slag by using reducing gas". Allow to cool. Utilize the reducibility of reducing gas and the oxidation of hexavalent chromium in chromium slag to undergo redox reaction at high temperature, so that hexavalent chromium can be changed into trivalent or lower compound chromium, thereby removing the water...

AI Technical Summary

Problems solved by technology

[0012] Although the above-mentioned methods do not require high-temperature treatment, they still need to use materials such as sludge and reducing bacteria, and there are many procedures and complicated processes, especially difficult to adapt to large-scale engineering applications.

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