Equipment and method for restoring heavy-metal-polluted soil by combination of leaching method and oxidation method

Abstract

The invention provides equipment for restoring heavy-metal-polluted soil by the combination of a leaching method and an oxidation method. The equipment comprises a leaching column, an oxidation tube, a first circulating pump and a second circulating pump, wherein the leaching column is internally provided with the polluted soil; a sieving mesh is arranged under the polluted soil, and a leaching nozzle is arranged above the polluted soil; the lower end of the leaching column is connected with a buffering groove, and the oxidation tube is connected with an absorbing tube; one end of the first circulating pump is connected with the buffering groove, and the other end of the first circulating pump is connected with the oxidation tube; one end of the second circulating pump is connected with the absorbing tube, and the other end of the second circulating pump is connected with a spraying tube. The equipment and the method provided by the invention have the advantages that since EDTA (Ethylene Diamine Tetraacetic Acid) is used as a leaching agent, heavy metal in the soil can be removed in a high-efficiency and fast manner, and the difficulties that the cost of the agent is large, the secondary pollution is caused and the subsequent treatment is relatively troublesome are overcome; by compounding of organic acid and a small amount of additive, the desorption and the solubilization of the heavy metal in the soil are enhanced, the application range of leaching liquid is expanded, a combined body of the leaching liquid and the heavy metal is easily absorbed for separation by an absorbing agent, and no secondary pollution to the environment is caused.

Description

technical field [0001] The invention relates to a device and a method for remediating heavy metal-contaminated soil, in particular to a device and a method for remediating heavy metal-contaminated soil by leaching and combined oxidation. Background technique [0002] In recent years, with the rapid development of industry, a large amount of waste water and waste residue containing heavy metals have been unreasonably discharged into the soil. The soil polluted by heavy metals in my country accounts for about 1 / 6 of the total cultivated land, and the amount of food polluted by heavy metals is as high as millions of tons every year. In some polluted sites, the coexistence of metal Cu, Pb, Zn and other complex pollution characteristics is more common, and the pollution concentration is relatively high. Due to the hidden, refractory, and irreversible characteristics of heavy metals, heavy metal-contaminated soil is not only unusable in large areas, but also endangers human life ...

AI Technical Summary

Problems solved by technology

At present, the research on the use of organic acids for the remediation of single-type metal-contaminated soils has achieved certain results, but there are few reports on the use of organic acids and additives to remediate polymetallic-contaminated soils and the treatment of leaching wastewater.

At the same time, the effective components of the eluting agent are greatly lost, the recovery time is long, and the recovered and concentrated pollutants are difficult to completely eliminate, which will easily cause the pollutants to enter the environmental system again, causing secondary pollution

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