Electric promoting eluting and removing device and method for soil heavy metal based on electric geotextile

Abstract

The invention provides an electric promoting eluting and removing device and an electric promoting eluting and removing method for soil heavy metal based on an electric geotextile. An eluting agent is applied to heavy metal polluted soil and the eluting agent and soil are uniformly mixed through a plowing machine, so that the heavy metal in the soil is desorbed into a soil solution through eluting; EKG electrodes are buried into the soil at intervals in parallel and are used as anode and cathode materials of electrodynamics; an interval electrifying manner is adopted under the potential gradient of 0.2V/cm-4V/cm, so that the heavy metal with positive charges in the farmland soil is desorbed into the soil solution through eluting, and is enriched to a cathode under the action of an electric field; then the heavy metal is transferred out of the soil under the action of circulating washing of electrode liquid; and the washed electrode liquid is treated and then is circularly used for washing an electrode. By adopting the electric promoting eluting and removing device and method, the effect of chemical eluting can be improved and the discharging of an eluent is promoted; and meanwhile, the problem of soil acidification and alkalization in an electric remediation process is effectively avoided, and the electrode can be conveniently and rapidly mounted and used in field.

Description

technical field [0001] The invention relates to the technical field of soil remediation, in particular to a device and method for removing heavy metals in soil by electric leaching based on electric geotextiles. Background technique [0002] With the development of industry and agriculture, the problem of soil pollution has become increasingly prominent, posing a serious threat to the lives and health of the people, and it is urgent to repair and treat soil contaminated by heavy metals. Chemical leaching is an efficient method for the remediation of heavy metal-contaminated soils, but it is not effective in removing low-permeability soils, and in-situ chemical leaching also faces the problem that the eluent is not easy to discharge. Electric remediation refers to the process in which low-voltage direct current is introduced into polluted soil, and pollutants migrate out of the soil through electromigration and electrodialysis under the action of an electric field. It is a gr...

AI Technical Summary

Problems solved by technology

The device is an in-situ repair (in-situ), which has a good effect on the treatment of persistent organic pollutants in the soil. For heavy metals in the soil, due to the unsolved cathode alkalinization, the heavy metals in the soil near the cathode are precipitated by alkali, so that the removal effect bad

[0006] The existing electrokinetic enhanced leaching repair methods for contaminated soil mainly have the following problems: (1) It is difficult to effectively promote the eluent to be discharged from the soil as soon as possible, and avoid the phenomenon of resistance polarization and concentration polarization, and improve the effect of electrodynamic leaching The removal rate of heavy metals; (2) the soil inevitably appears anodic acidification and cathodic alkalinization, and many studies control the pH value of the electrolyte by adding acid-base buffers, but the use of these chemicals has potential hazards to the environment; (3) The in-situ repair (in-situ) method has high requirements on the convenience of on-site installation and operation, and how to conveniently and quickly carry out on-site installation and use of electrodes has become one of the restrictive factors

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