Method for in-situ remediation of heavy metal contaminated soil

Abstract

The invention provides a method for in-situ remediation of heavy metal contaminated soil. The method comprises the following steps that a modifying agent is diluted by adding water; the diluted modifying agent is sprayed on the heavy metal contaminated soil to be mixed with the soil; curing agent particles and complexing agent citric acid are uniformly mixed to obtain a mixture; through a tractor-ploughing method, the mixture is seeded into the soil remediated through the modifying agent; and through a weighing method, the water content of the soil is kept through watering. According to the method for in-situ remediation of the heavy metal contaminated soil in a modifying agent and curing agent combined mode, operation is easy, the cost is low, the remediation effect is good, the soil aggregated structure can be effectively improved, and soil fertility can be effectively improved; and the method is suitable for treating of large-area contaminated soil, various heavy metal inside the soil can be removed, particularly, the removing effect on Pb, Zn, Cu and Cd is good, the heavy metal inside the soil is prevented from migrating into plants, absorption of the plants for the heavy metalis reduced, and secondary contamination cannot occur.

Description

technical field [0001] The invention relates to the technical field of soil remediation, in particular to a method for in-situ remediation of heavy metal polluted soil. Background technique [0002] In the mining of mineral resources, especially in the process of mining of metal mineral resources, heavy metal elements in waste rock tailings, smelting wastewater, and waste gas floating dust are the main pollution sources of the mining area environment. The heavy metal content in the surrounding soil increases through polluted irrigation and atmospheric dust. , thus polluting soil, surface water, and groundwater. [0003] Soil improvement measures are to add one or more substances to the soil, improve the adsorption capacity of heavy metals in the soil by changing the physical and chemical properties of the soil, or directly interact with heavy metals to form complexes or precipitates with low solubility, thereby reducing the concentration of heavy metals in the soil. Migrati...

AI Technical Summary

Problems solved by technology

At present, the main curing agents include cement, lime, fly ash, etc., which have narrow application areas and high cost, and some curing agents themselves have secondary pollution, such as fly ash, and the long-term curing effect of the curing agent is unstable.