Effect of pH Control at the Cathode for the Electrokinetic Remediation Efficiency

摘要

Electro kinetic remediation, variably named as electrochemical soil processing, electro migration, ectrokinetic decontamination or electro reclamation, uses electric currents to extract radio nuclides, heavy metals, certain organic compounds, or mixed inorganic species and some organic wastes from soils and slurries. This paper presents the experimental study on the effect of control at the cathode for the electro kinetic remediation efficiency of the chromium polluted soils at laboratory scale. Potassium dichromate was chosen as the pollutant and its initial concentration was 100mg•kg-1 soil and 500mg•kg-1 soil. 1 DCV/cm voltage was applied, and the experiments were operated for 48h. The results indicate that pH control at the cathode can improve the removal efficiency of hexavalent chromium from kaolin significantly, and the electric energy consumption changed slightly. Neutralizing the OH result from the electro analysis of cathode with hydrochloric acid is the most effective method out of the several methods investigated, and the removal efficiency of hexavalent chromium reaches up to 90.8%, but it is necessary to do more research to prevent the acidification of soils. Also, the movement and transformation of hexavalent chromium in soils should be studied thoroughly.