Chromium-contaminated soil remediation method

A remediation method and chromium pollution technology, applied in the field of environmental engineering, can solve the problems of backward chromium-contaminated soil treatment technology, secondary pollution and high environmental risks, and low efficiency of chromium-contaminated soil remediation, so as to reduce environmental risks and speed up Precipitation and concentration, the effect of saving resources and cost

Inactive Publication Date: 2013-05-15
INST OF ROCK AND SOIL MECHANICS - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] At present, the remediation technologies for composite chromium-contaminated soil mainly include microbial removal, chemical methods (pharmaceutical washing, thermal decomposition, etc.), physical methods (electric current makes charged ions migrate, etc.) and planting plants. A large number of methods ar

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment example 1

[0039] Add 0.01mol / LKH to 300kg of chromium-contaminated soil 2 PO 4Solution 1500kg, infiltrated for 1 hour, then stirred for 10min, then filtered on a filter plate with a membrane surface aperture of 4um, rinsed the chromium-contaminated soil on the filter plate with tap water for 10min, collected the trivalent chromium-contaminated soil on the filter plate and filtered the six Chromium-valent sewage, the weight of trivalent chromium-contaminated soil is 500kg, and the total volume of hexavalent chromium sewage is 1300L. Crack municipal sludge at a high temperature of 300°C to make sludge biochar, add 1.0kg of sludge biochar to filtered trivalent chromium-contaminated soil, stir evenly before agricultural use. The content of hexavalent chromium in the hexavalent chromium sewage was measured to be 300mg / L, and 1.365kg Na was added to the filtered hexavalent chromium sewage 2 S 2 o 5 , adjust the pH of the solution to be 4, add 10kg of polyaluminum chloride after stirring e...

Embodiment example 2

[0041] Add 0.05mol / LKH to 300kg of chromium-contaminated soil 2 PO 4 Solution 2400kg, infiltrated for 1 hour, then stirred for 10min and then filtered on a filter plate with a membrane surface aperture of 4um, rinsed the chromium-contaminated soil on the filter plate with tap water for 15min, collected the trivalent chromium-contaminated soil on the filter plate and filtered the six Chromium-valent sewage, the weight of trivalent chromium-contaminated soil is 600kg, and the total volume of hexavalent chromium sewage is 2100L. Make sludge biochar from municipal sludge at a high temperature of 300° C., add 3.0 kg of sludge biochar to filtered trivalent chromium-contaminated soil, stir evenly, and then use it in agriculture. The content of hexavalent chromium in the hexavalent chromium sewage was measured to be 700mg / L, and 5.145kg Na was added to the filtered sewage 2 S 2 o 5 , adjust the pH of the solution to be 5, add 10kg polyaluminum iron silicate after stirring evenly, ...

Embodiment example 3

[0043] Add 0.1mol / LKH to 300kg of chromium-contaminated soil 2 PO 4 Solution 3000kg, infiltrated for 1 hour, then stirred for 10min, and filtered on a filter plate with a membrane surface aperture of 4um, rinsed the chromium-contaminated soil on the filter plate with tap water for 20min, collected the trivalent chromium-contaminated soil on the filter plate and filtered the six Chromium-valent sewage, the weight of trivalent chromium-contaminated soil is 700kg, and the total volume of hexavalent chromium sewage is 2600L. Municipal sludge is made into sludge biochar at a high temperature of 300°C, and 7.0kg of sludge biochar is added to the filtered soil, stirred evenly, and then used for agriculture. The content of hexavalent chromium in the hexavalent chromium sewage was measured to be 900mg / L, and 8.19kgNa was added to the filtered sewage 2 S 2 o 5 , adjust the pH of the solution to be 6, add 10kg of polyacrylamide after stirring evenly, filter with a filter plate after ...

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PUM

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Abstract

The invention discloses a chromium-contaminated soil remediation method, belonging to the technical field of environment engineering. The method comprises the following steps of: dissolving out hexavalent chromium in the chromium-contaminated soil, separating the soil from water, treating trivalent chromium-contaminated soil, treating hexavalent chromium sewage and treating filter residue; the dissolution efficiency of the hexavalent chromium in the chromium-contaminated soil can be improved by the KH2PO4 solution; the trivalent chromium-contaminated soil is treated by biochar made of municipal sludge, so that waste reclamation and secondary utilization of the contaminated soil can be realized; Na2S2O5 can be added into the hexavalent chromium sewage and is used for adjusting the reaction environment, so that the efficiency of converting hexavalent chromium into trivalent chromium can be improved; a flocculating agent is used for accelerating the precipitation and concentration of the trivalent chromium; the filtered water can be used as flushing water for recycling, so that the method is economical and environment-friendly; and a curing stabilization method is used for treating the filter residue, so that the chromium in the filter residue is passivated, and the national environmental standard requirements can be reached. According to the method, the hexavalent chromium and the trivalent chromium are respectively treated, and the solid and the solution are respectively treated, so that the treatment efficiency is improved, the treatment effect is guaranteed, and the method has the characteristics of being free from secondary pollution, low in cost, high in resource utilization rate, etc.

Description

technical field [0001] The invention discloses a method for repairing chromium-contaminated soil, which belongs to the technical field of environmental engineering. Background technique [0002] At present, nearly 20 million hectares of arable land are polluted by heavy metals such as chromium, cadmium, arsenic, and lead in my country. It is estimated that 12 million tons of grains are polluted by soil every year, causing direct economic losses of more than 20 billion yuan. With the acceleration of urbanization and industrialization, more and more land is polluted by heavy metals, the strategic layout of cities has been readjusted, and a large number of heavy metal legacy sites are in urgent need of treatment. According to statistics, there are about 5 million tons of chromium slag left in my country, most of which have not been treated, causing huge hidden dangers to the environment. Soil heavy metal pollution is concealed, lagging and long-term. Heavy metals enter plants ...

Claims

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Application Information

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IPC IPC(8): B09C1/00
Inventor 薛强李江山王平陈益人赵颖
Owner INST OF ROCK AND SOIL MECHANICS - CHINESE ACAD OF SCI
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