Method for shielding polarization phenomenon in process of repairing arsenic-polluted soil by electrically-driven reinforced permeable reactive barrier

Abstract

The invention discloses a method for shielding a polarization phenomenon in a process of repairing arsenic-polluted soil by an electrically-driven reinforced permeable reactive barrier. The method is characterized in that: the pH value of the repaired soil is adjusted by changing an electrolyte of an electrically-driven reinforced permeable reactive barrier device for the arsenic-polluted soil, and the repairing effect is improved by 20%. The method comprises the following steps: naturally air-drying the arsenic-polluted soil, performing crushing and sieving, performing uniform mixing and stirring with deionized water, and performing standing for 7 days; and filling a reaction device with the obtained soil, performing repairing under the voltage of 1-3 V / cm, placing a PRB material in the middle of the reactor, and adding 0.1-0.5 mol / L of C6H8O7.H2O and 0.1-0.5 mol / L of NaOH electrolyte to a cathode and an anode respectively. Different acid and alkali solutions can be selected as the electrolyte according to the arsenic pollution concentration and property. The reaction device is composed of a soil chamber, an electrode chamber and an external circulation system. The method can effectively control the adverse effect of too high / low pH at the two ends of the soil chamber on the experiment, the arsenic removal rate is improved while the soil pH value is adjusted, the polarization phenomenon shielding effect is good, the pollutant removal rate is high, and the method has the field implementation performance.

Description

technical field [0001] The invention belongs to the technical field of remediation of soil heavy metal pollution in the environmental protection technology, and in particular relates to a method for remediating arsenic-contaminated soil by electrically driving and strengthening a permeable reaction wall. Background technique [0002] Arsenic is a toxic and carcinogenic metalloid element, one of the five major poisons of environmental pollution, and is listed as the first category of pollutants in environmental protection standards. The sources of soil arsenic pollution include metal mining and smelting, chemical industry production, heavy metal pesticide sewage irrigation and chemical fertilizer application, and high geological background value. Arsenic can migrate and diffuse in the environment. Part of the arsenic in the soil is absorbed by crops and part of it enters the water body with precipitation and river erosion, and finally enters the human body through the food ch...

AI Technical Summary

Problems solved by technology

This polarization phenomenon of the soil will greatly limit the ionization of pollutants in the soil, and thus be electrically driven to break away from the limitation of interstitial water in the soil, and reach the PRB in contact with the filler, thus limiting the removal of target pollutants in the soil

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