Heavy metal Cr(VI) contaminated soil EK-PRB combined remediation method and device

Abstract

The invention relates to a heavy metal Cr(VI) contaminated soil EK-PRB combined remediation method. Under the condition of a certain moisture content, the method depends on electrokinetic remediation (EK), a permeable reactive barrier (PRB) technology is used in a combined manner, and heavy metal Cr(VI) in soil is subject to combined remediation. Materials related in a permeable reactive barrier (PRB) in the method are lamellar double hydroxide CaAl-LDH. According to electrokinetic remediation in the method, the Cr(VI) can be effectively subject to enrichment concentration, the lamellar double hydroxide CaAl-LDH serves as the PRB of a reaction medium to assisting in electrokinetic remediation, Cr(VI) pollution migrated to an anode is fixed, the maneuverability of the electrokinetic technology is improved, and the method is expected to be applied to practical remediation of other anions. The method has the beneficial effects of being safe, reliable, convenient to operate, low in cost and the like. In addition, the lamellar double hydroxide CaAl-LDH in the method can be regenerated within a certain temperature scope to recover to an original lamellar structure to be repeatedly used.

Description

technical field [0001] The invention is an EK-PRB combined restoration method for efficiently treating heavy metal chromium (VI) polluted soil, belongs to the technical field of soil pollution control, and relates to an EK-PRB combined restoration technology for heavy metal contaminated soil. Background technique [0002] As of 2012, the nationally polluted arable land area was 1.5×10 9 Mu, the pollution caused by sewage irrigation is about 3.25×10 7 mu, the destroyed land and solid waste stockpiles occupy an area of ​​about 2×10 6 Mu, accounting for more than 10% of the total arable land in the country, the land pollution is extremely serious, and the crop yield reduction caused by heavy metal pollution in the soil is as high as 1×10 7 tons, grains contaminated by heavy metals amounted to 1.2×10 7 tons, and the direct economic loss is about 20 billion yuan. [0003] Heavy metals have poor mobility in soil, and have the characteristics of long residual time, high toxicit...

AI Technical Summary

Problems solved by technology

However, due to differences in soil composition, pollutant types, properties, etc., especially in the case of complex pollution where different forms of chromium pollutants exist at the same time, it is often difficult for traditional remediation technologies to achieve the purpose of remediation quickly and efficiently.

Traditional heavy metal-contaminated soil treatment methods have many shortcomings such as high cost, damage to soil structure and fertility, easy to cause secondary pollution, and large disturbance to the soil environment.

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