Composite curing agent for restoring soil polluted by heavy metals and application method thereof

Abstract

The invention relates to the field of soil restoration, in particular to a composite curing agent for restoring soil polluted by heavy metals and an application method thereof. The composite curing agent is composed of curing agent powder and curing agent liquid. The curing agent powder comprises, by weight parts, 2-5 parts of cement, 1-2 parts of activated steel slag powder, 2-4 parts of quicklime and 1-2 parts of phosphate, and the curing agent liquid is water glass. By adoption of the composite curing agent for restoring soil polluted by the heavy metals, heavy metal pollutants in the soil can be solidified and stabilized durably and effectively, and the composite curing agent has the advantages of being good in restoration effect and high in stability. The content of effective state heavy metals in the restored soil is lower than the national standard, and the soil has the advantages of being not subjected to cracking easily and secondary argillization.

Description

Technical field [0001] The invention relates to the field of soil remediation, in particular to a composite solidifying agent for remediating heavy metal contaminated soil and an application method thereof. Background technique [0002] With the continuous development of my country's industry and mining industry, a large number of heavy metal pollutants are discharged into the soil environment, causing serious soil pollution problems, and sustainable social and economic development is facing severe challenges. Soil heavy metal pollution will not only lead to the reduction of the activity of microorganisms and enzymes in the soil, but also cause continuous secondary pollution to the surrounding water environment and food chain, seriously affecting people's normal production and life. Therefore, it is very urgent and necessary to effectively repair the soil contaminated by heavy metals. [0003] Current soil heavy metal pollution remediation technologies mainly include electrodynami...

AI Technical Summary

Problems solved by technology

The electrodynamic remediation method makes the heavy metal pollutants in the soil directional migrate by applying an electric field, so as to achieve the purpose of remediating the soil. This method is green and environmentally friendly without secondary pollution, but it has high energy consumption, small remediation range, and is not suitable for soil remediation in acidic conditions. Disadvantages: Soil leaching is a method of removing pollutants in the soil by using water, surfactant solution and inorganic salt solution as the eluent. This method has a short repair period and high removal efficiency, but has a great impact on the physical and chemical properties of the soil. The cost is high and may cause secondary pollution; bioremediation is a hot spot in current research, but the repair rate is slow and the period is long, making it difficult to be widely promoted; the curing and stabilization repair method is simple, low in cost, and high in efficiency. Good application prospect

However, the current soil stabilization and restoration technology has problems such as poor stability after restoration, easy cracking, and "secondary muddying" phenomenon. Therefore, it is very necessary to develop new solidification agents and restoration methods for soil heavy metal pollution restoration. up