Method for remedying halohydrocarbon contaminated site through combination of chemical leaching and microorganisms

Abstract

The invention relates to a method for remedying a halohydrocarbon contaminated site through combination of chemical leaching and microorganisms, in particular to a leaching method and a microorganism remediation method. The method for remedying the halohydrocarbon contaminated site comprises steps as follows: chemical leaching is adopted, leachate is injected into contaminated soil through an injection well, and the leachate with pollutants is pumped out from an extraction well at the downstream part of the contaminated site. The method is characterized in that the major component of the leachate is a biological surfactant dissolved in an alcohol-water mixed solution, and after the contaminated site is leached by the leachate, a KB1 bacteria suspension is injected into the contaminated soil for microorganism remediation. Due to leaching with the chemical method, the early-stage remediation for the high-concentration halohydrocarbon contaminated site can be realized quickly, then with the adoption of microorganism remediation, the problems that the low-concentration pollutant leaching effect of the chemical leaching technology is poor and the concentration of pollutants is rebounded after leaching can be solved, and the purpose of complete remediation of the halohydrocarbon pollutants is achieved.

Description

technical field [0001] The invention relates to a restoration method for halogenated hydrocarbon-contaminated sites, in particular to a washing method and a microbial restoration method. Background technique [0002] The increasingly serious soil pollution has caused great harm to food security and ecological security. Numerous substances that cause soil pollution include heavy metals, organic pollutants, pesticides, herbicides, POPs, and fertilizers. These pollutants are not only deposited and enriched on the soil surface, but also diffuse into the aquifer below the soil layer, thereby contaminating groundwater and causing greater health risks. Among various pollutants, halogenated organic compounds are more likely to deposit into underground aquifers to form a substance called heavy non-aqueous phase liquid (dense non-aqueous phase liquid) due to their specific characteristics such as higher density than water and low solubility in water. -aqueous phase liquids, DNAPLs),...

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Problems solved by technology

[0003] For the remediation of halogenated hydrocarbon-contaminated sites, the main technologies include bioremediation technology, chemical oxidation / reduction technology, improved gas phase extraction technology, chemical leaching technology, etc., but these technologies are more or less deficient, such as bioremediation technology Usually, due to the high concentration of halogenated hydrocarbon pollutants, the microorganisms are poisoned, thereby weakening the effect of bioremediation; while the chemical oxidation / reduction technology is difficult to ensure that the injected chemical reagents reach the pollution sources in the aquifer accurately. Usually, the residence time in the pollution source area is short, which cannot meet the needs of sufficient oxidation / reduction of pollutants; during the chemical leaching process, the chemical leaching agent will form a preferential flow path in the underground aquifer after being injected into the underground aquifer, resulting in low The pollutants in the permeable local area cannot be leached out, and the concentration of pollutants will rebound after leaching, which will finally affect the leaching effect

In addition, chemical leaching is not effective for low-concentration pollutants

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