Experiment on electrokinetic remediation of cadmium contaminated soil under different voltages

摘要

The electrokinetic remediation method of soil contaminated by heavy metal was researched cadmium by means of experiments in this paper, and the characteristic and mechanism for distribution and migration of heavy metal under an electric field were analyzed too. The experimental results indicated that the concentrations of heavy metal varied obviously in soil in electric field and the heavy metal pollutants can be enriched and removed in the vicinity of electrodes. And the pH value and voltage, etc. in soil were the main factors which affected the effect of electrokinetic remediation. The removal efficiency of cadmium in the soil near positive electrode were 70.7%, 79.7% and 90.6% respectively when the experimental voltages were 0.5V/cm, 1.0V/cm and 2.0V/cm. So the removal efficiency of cadmium increased clearly with the voltages rose. The pH value near the positive electrode changed from 6.8 in initial stage to 5.3 at later stage, and the pH value was on the contrary closing to the negative electrode, namely, varied from 6.7 in the beginning to 8.8 in the last when the experimental voltage was 0.5V/cm, which made known that the condition of acidity and alkalinity in soil varied clearly. In addition, the temperature near electrodes varied during the process of electrokinetic remediation.