Diatomite-containing curing agent for controlling heavy-metal-contaminated soil

Abstract

The invention relates to the technical field of control of contaminated soil, in particular to a diatomite-containing curing agent for controlling heavy-metal-contaminated soil. The curing agent has the following materials by weight percent: 25-40 percent of cement, 40-65 percent of diatomite and 10-20 percent of calcined lime. The invention has the advantages of having no risk of secondary pollution while the diatomite fixes the heavy metal ions and having no obvious change for the properties of natural soil. The composition of minerals of the diatomite is very close to that of undisturbed silty clay, so that larger damage caused by the cement and the calcined lime to a soil body structure is avoided. Due to the advantage, the curing agent has very obvious effect for restoring agricultural lands contaminated by heavy metal surface sources, and has good social, economic and environmental benefits.

Description

technical field [0001] The invention relates to the technical field of contaminated soil treatment, in particular to a diatomite-containing curing agent for treating heavy metal-contaminated soil. Background technique [0002] At present, the remediation technologies for heavy metal-contaminated soil mainly include: replacement and filling method, biological remediation method, chemical fixation method, electrodynamic remediation method, etc. Among them, the replacement method is only suitable for small areas and heavily polluted soil; the bioremediation method has the advantages of low treatment cost and high cleaning level, but it takes a long time for restoration and is greatly limited by the type of pollutants; The repair method has different effects in different soil types, or even has the opposite effect, and the cost is high and the operation equipment is complicated, which is not conducive to large-scale application. The solidification and remediation technology of ...

AI Technical Summary

Problems solved by technology

Its main disadvantages are: the application area is narrow, that is, some curing agents are effective for some heavy metal ions but not effective for others; the cost is high; some curing agents themselves have secondary pollution, such as fly ash; the curing agent is cured for a long time The effect is unstable. For example, the organic curing agent is easy to decompose after two or three years, so the fixed heavy metal ions may be released again.

[0004] Moreover, the above-mentioned curing agent is used to treat polluted soil. Although the polluted soil after treatment can be used as filling materials such as foundations and roadbeds, there is often no such construction work around the polluted soil, and after adding curing agents such as cement and lime Vegetation cannot be planted on the polluted soil, it can only be buried deep in the ground