A local strengthening device for soil electrodynamic restoration and its application

Abstract

The invention provides a local strengthening device for electrokinetic soil remediation and application thereof. The local strengthening device comprises an outer sleeve layer and two cavities covered by the outer sleeve layer, wherein the two cavities are filled with a sponge body dipped with a conductive solution and hydrogen-form cation exchange resin, respectively. Under the action of a direct current electric field, heavy metal ions at the upstream are gradually enriched in a high-conductivity zone; ions in the high-conductivity zone migrate into the hydrogen-form cation exchange resin; after ion exchange occurs, the hydrogen-form cation exchange resin releases H<+>; due to release of acid, soil at the downstream is acidified, so that rise of the pH value of the soil at the downstream is effectively suppressed; therefore, desorption of the heavy metal ions in the soil is facilitated, and the electrokinetic remediation effect is enhanced.

Description

technical field [0001] The invention relates to the technical field of soil restoration, in particular to a local strengthening device for electrodynamic restoration of soil and its application. Background technique [0002] Electrodynamic remediation is to add DC electrodes to both ends of the polluted soil to achieve the purpose of removing pollutants and remediating the soil. The basic mechanism is: the water in the soil undergoes an electrolytic reaction under the action of an electric field, the anode produces oxygen and hydrogen ions, and the cathode produces hydrogen and hydroxide ions. H produced at the anode + Under the action of electric field and concentration gradient, it migrates and diffuses into the soil to form an acid zone. h + In the process of migration and diffusion, the heavy metal ions adsorbed by the soil are desorbed, and react with sediments such as heavy metal oxides, hydroxides, and carbonates in the soil, so that the heavy metal pollutants in t...

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Problems solved by technology

Although this method uses artificial focusing to remove heavy metal pollutants, the artificial high conductivity soil increases the ion content in the soil. During the restoration process, these ions enter the downstream soil to be repaired in large quantities, which will make the artificial high conductivity zone downstream soil (Ions released from the high conductivity band, the soil on its migration path) The concentration of ions increases, making repairing more difficult. In addition, a large number of added ions are introduced into the soil, which will "flood" the pollutant ions in the soil. When the external current When constant, the effective current acting on the pollutant ions decreases, and the repair efficiency decreases

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