Comparative Study on Electrode Arrangement in Electrokinetic Remediation of Contaminated Soil

To improve the efficiency of electrokinetic remediation of contaminated soil, by introducing single pollutant cadmium and setting up a self-made device test, electrokinetic remediation technology was applied to artificially simulated contaminated soil to explore the influence of three different two-dimensional electrode arrangements [triangle (2-e-1), rectangle (2-e-2) and hexagon (2-e-3)] on electrokinetic remediation of cadmium contaminated soil in this paper. The cathode of the test device was made of high purity (99.9%) graphite electrode, and the anode was made of stainless steel electrode. Under the condition that the voltage gradient, electrode material, electrolyte and electrification time of the three groups of tests were consistent, the current change, pH value, conductivity, total cadmium content and cadmium morphology of the three groups of tests were compared. The experimental results showed that the triangle (2-e-1) group, the current increased slowly during the process of power on, the pH value of soil was over acid, and the transformation rate of various forms of cadmium contained in the soil after the restoration was low. The current change rate of the rectangular (2-e-2) electrode arrangement was the highest, the soil environment was super alkaline, and the removal rate of cadmium was an average level. The hexagonal electrode arrangement (2-e-3) led a large current drop rate and a weakly alkaline pH environment, the removal efficiency of cadmium at sampling points (S1 and S2) near the anode was as high as 95.54%, and the comprehensive removal rate of cadmium at each sampling point reached 89.6%, moreover, the pollutant removal was uniform and efficient. © 2021 Technoscience Publications. All rights reserved.