Composite stabilizing agent for hexavalent chromium polluted soil and application of composite stabilizing agent

Abstract

The invention discloses a composite stabilizing agent for hexavalent chromium polluted soil and application. The composite stabilizing agent comprises the following components in parts by weight: 20-50 parts of nano zero-valent iron, 10-40 parts of ferrous sulfide, 10-40 parts of calcium polysulfide, 8-20 parts of ferrous citrate, 5-20 parts of oxalic acid, 5-20 parts of lactic acid, 3-15 parts ofglucose, 3-15 parts of edible oil, 5-20 parts of bentonite, 5-20 parts of zeolite, 5-20 parts of medical stone, 8-20 parts of EDTA and 8-20 parts of tartaric acid. After the composite stabilizing agent is used for reducing and stabilizing the hexavalent chromium polluted soil, the total amount of hexavalent chromium reaches the national standard; and the toxic leaching concentration of hexavalentchromium is quite low, the acidity and alkalinity of a soil environment cannot be changed, the circumstance that a large amount of inorganic salts are introduced to cause salinization of the soil environment is avoided, and meanwhile, the agent brings carbon sources to indigenous microorganisms in the soil environment and activates the indigenous microorganisms.

Description

technical field [0001] The invention belongs to the field of hexavalent chromium pollution control, and relates to a composite stabilization agent for hexavalent chromium polluted soil and its application. Background technique [0002] Chromium and its compounds are widely used in electroplating, metalworking, tanning, dyes, steel and chemical industries. The chromium-containing wastewater discharged from the tanning industry and the dissolved industrial chromium residues can pollute many surrounding soils and groundwater. Chromium has been regarded as an important environmental pollutant. Chromium usually exists in nature in trivalent and hexavalent forms, and hexavalent chromium is the most toxic to organisms and humans. Hexavalent chromium is a highly toxic element and has high carcinogenicity. The lethal dose of hexavalent chromium compounds in human body is about 1.5g, and the content of hexavalent chromium in water exceeds 0.1mg / L, which will cause poisoning. Cr(VI) ...

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Problems solved by technology

[0005] In order to solve the technical problems in the prior art that the chemical reduction method and the chemical leaching method destroy the function of soil vegetation, easily introduce secondary pollution, and the microbial method cannot efficiently and thoroughly repair hexavalent chromium-contaminated soil, the purpose of the present invention is to provide a Composite stabilization agent for hexavalent chromium-contaminated soil, after the reduction and stabilization treatment of hexavalent chromium-contaminated soil is carried out through the synergistic effect between the components of the composite stabilization agent of the present invention, the total amount of hexavalent chromium reaches the national standard; The toxic leaching concentration of chromium is very low, and it will not change the acidity and alkalinity of the soil environment, and will not introduce a large amount of inorganic salts to cause salinization of the soil environment. At the same time, the agent will bring carbon sources to the indigenous microorganisms in the soil environment and activate the indigenous microorganisms

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