Remediation method of stabilization/solidification of lead-polluted soil

Abstract

The invention discloses a remediation method of stabilization / solidification of lead-polluted soil. According to the method, a FeSO4 solution is added to the heavy metal lead-polluted soil, so that H+is generated through oxidization of the Fe2+, thus reducing pH value of soil, and promoting the conversion of instable lead in the soil into an effective state; then biochar and phosphate are added to the heavy metal lead-polluted soil, so that through adsorption, complexness, kation exchange, precipitation and the like between the biochar and phosphate and lead ions, the lead of effective stateis further converted into a lead compound in a stable residue state, thereby reducing the bio-availability of the heavy metal, reducing the content of the heavy metal in effective state in soil, and achieving adsorption and stabilization treatment of lead. The remediation method can reduce the leaching concentration of a leachate from the lead-polluted soil to lower than type III water quality standard (0.01 mg / L) according to the Quality Standard for Ground Water GBT 14848-2017.

Description

technical field [0001] The invention relates to the technical field of soil restoration, in particular to a restoration method for stabilization / solidification of lead-contaminated soil. Background technique [0002] With the development of my country's economy and rapid industrial development, cities continue to expand the scale of development for economic development, electroplating, chemical and mechanical processing enterprises are gradually increasing, and processing waste is increasing, containing a large amount of heavy metal lead. In the case of treatment, it is discharged into the soil, which greatly increases the content of heavy metal lead in the soil. In addition, during the development of my country's agriculture, the use of a large amount of pesticides has also increased the degree of soil pollution to a certain extent. The heavy metal lead continues to accumulate in the soil, causing great harm to the healthy growth of crops and threatening people's health. . ...

AI Technical Summary

Problems solved by technology

[0006] In order to overcome the secondary pollution problems that the existing technology may cause secondary pollution caused by the redissolution of heavy metal lead-contaminated soil after remediation and the influence of traditional medicaments on soil salinization, etc., the present invention provides a method for converting combined heavy metal lead in soil into effective It is a low-cost and remedial method for the stabilization / solidification of lead-contaminated soil that can be transformed into a residue state, and has a regulatory effect on the soil, so as to realize the long-lasting and complete mineralization and stabilization of the heavy metal lead in the soil.