Method for repairing chlorinated hydrocarbon-contaminated site through in-situ chemical oxidation

Abstract

The invention relates to a method for repairing a chlorinated hydrocarbon-contaminated site through in-situ chemical oxidation. The method comprises the following steps of: spraying fine sand into theground by using a powder spray pile machine to improve the content of sand grains in soil and improve a soil structure so as to achieve a better water permeation effect; spraying a mixture of an oxidizing agent, a catalyst and cement into the ground by using the powder spray pile machine, and wrapping the reagents into a ball after the cement is cured so as to achieve the purpose of slow release;separately spraying fine sand into the ground by using the powder spray pile machine, then spraying a mixture of the catalyst and the cement into the ground by using the powder spray pile machine, and spraying the mixture into a downstream position of underground water; and after the cement is solidified, injecting hydrogen peroxide into an upstream position of underground water through an injection well. According to the invention, the fine sand can increase the content of soil sand grains and improve the soil structure to achieve a good water permeable effect; the solidified cement wraps the oxidizing agent and the catalyst to form a ball, so dissolution of the reagents can be effectively delayed; and the water permeable structure formed by spraying of the fine sand provides a good channel for a contact reaction of hydrogen peroxide and the catalyst, so the oxidation efficiency of the oxidizing agent is improved.

Description

technical field [0001] The invention relates to a method for repairing chlorinated hydrocarbon polluted sites by in-situ chemical oxidation, and belongs to the field of in-situ chemical oxidation methods for soil. Background technique [0002] As important chemical raw materials and organic solvents, chlorinated hydrocarbon solvents are widely used in the chemical industry. Due to the mass production, use, and improper storage of chlorinated hydrocarbons, they enter the soil and groundwater and become common pollutants in the environment, especially chloroform, trichloroethane, trichloroethylene, and tetrachloroethylene. Chlorinated hydrocarbons are usually carcinogenic, teratogenic, and mutagenic, and their high carbon-hydrogen bond energy enables chlorinated hydrocarbons to persist in the environment, increasing their toxic impact on human health and the ecological environment. Most of the chlorinated hydrocarbons are heavy non-aqueous liquids with low solubility and high...

AI Technical Summary

Problems solved by technology

However, due to the complexity of soil structure and chemical composition, humic acid, reducing metals and other substances in the soil will consume a large amount of oxidants

In addition, the migration direction and range of chemical oxidants injected into the soil are not directional, and in areas with poor soil permeability, the transmission rate of chemical oxidants is slow, which affects their oxidation efficiency.

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