Repairing agent for repairing hexavalent chromium contaminated soil and method for repairing hexavalent chromium contaminated soil by using repairing agent

Abstract

The invention provides a repairing agent for repairing hexavalent chromium contaminated soil and a method for repairing hexavalent chromium contaminated soil by using the repairing agent. The repairing agent can reduce hexavalent chromium and prevent trivalent chromium from being converted into hexavalent chromium. The repairing agent for repairing hexavalent chromium contaminated soil comprises the following components in percentage by weight: 20-35% of a calcium polysulfide solution with the concentration of 29%; 10-20% of a curing agent; 50-655 of water; the method for repairing hexavalentchromium contaminated soil comprises the following steps: S1, preparing a repairing agent, specifically, stirring and mixing a calcium polysulfide solution with the concentration of 29%, a smashed curing agent and water to be uniform according to the proportion, and obtaining the repairing agent and putting into a medicine storage device for use; S2, preparing materials, namely digging to-be-repaired soil from the contaminated land for later use; S3, performing primary repairing treatment, specifically, using a soil remediation machine for conducting rolling crushing and drug application on to-be-repaired soil in the repairing process; and S4, performing repairing post-treatment is conducted, specifically, using soil remediation machine for stirring the primarily repaired soil in the repairing process.

Description

technical field [0001] The invention relates to the technical field of soil remediation, and relates to a remediation agent for repairing hexavalent chromium-contaminated soil and a method for using the same to repair hexavalent chromium-contaminated soil. Background technique [0002] Chromium is an element that exists widely in nature. It is mainly divided into trivalent chromium and hexavalent chromium. Most of the chromium in nature exists in the form of trivalent chromium with low toxicity, while hexavalent chromium is produced after industrial activities. , highly toxic and carcinogenic. In recent years, chromium and its compounds have been widely used in production, but due to oversight oversight, improper disposal and other reasons, hexavalent chromium pollution incidents occur frequently, posing a huge threat to the local ecological environment and human health. [0003] The Chinese patent publication number is CN201510159414.3, which discloses the use and restorat...

AI Technical Summary

Problems solved by technology

In recent years, chromium and its compounds have been widely used in production, but due to oversight oversight, improper disposal and other reasons, hexavalent chromium pollution incidents occur frequently, posing a huge threat to the local ecological environment and human health

[0003] The Chinese patent publication number is CN201510159414.3, which discloses the use and restoration method of calcium polysulfide in the restoration of chromium-contaminated soil or groundwater. Calcium sulfide remediation method for chromium-contaminated soil; including soil chromium pollution degree investigation, preparation of calcium polysulfide water agent, determination of dosage ratio of calcium polysulfide water agent, addition of calcium polysulfide water agent, water replenishment, remediation reaction, soil Soil property adjustment after maintenance and remediation; remediation methods for remediating chromium-contaminated groundwater with calcium polysulfide, including arranging injection points and determining the dosage of remediation agents, preparing remediation agents, positioning injection points, injecting calcium polysulfide remediation agents, and adjusting injection point positions and the number of injection points. This method only uses calcium polysulfide to reduce the hexavalent chromium in the soil, but does not consider the possibility that the trivalent chromium in the soil is re-oxidized to hexavalent chromium, and does not consider cutting off the trivalent chromium to hexavalent chromium. transformation pathway, so its remedial effect may be limited to a certain extent, and this method uses in-situ injection to remediate groundwater. For soil contaminated by chromium, in-situ injection cannot make the liquid medicine contact with the soil very well. , the influence of the medicine will also be weakened when the medicine liquid penetrates downward and spreads outward, resulting in the uneven combination of the soil and the medicine liquid, and the repair effect will not increase.

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