Electrokinetic remediation of chromium- and cadmium-contaminated soil from abandoned industrial site

This paper presents a systematic bench-scale study on removals of Chromium (Cr) and Cadmium (Cd) from abandoned industrial site in China with concentration of 510 mg/kg for Cr and 200 mg/kg for Cd. The polarity exchange and conventional electrokinetic remediation were conducted with treatment time of 192 h to assess the removal efficiency and transient behavior of Cr and Cd. All the experiments were subjected to a voltage gradient of 1 V/cm. Results showed that, polarity exchange electrokinetic remediation led to 88% of Cr and 94% of Cd removals when exchange polarity interval was 48 h. Seventy percent of Cr and 82% of Cd were removed when exchange polarity interval was 96 h. The removal efficiency was comparable with conventional electrokinetic remediation with removals of 57% of Cr and 49% of Cd. Soil pH was controlled between 5 and 7 by polarity exchange electrokinetic remediation. Additional chemicals and complex equipment were not required. (c) 2012 Elsevier B.V. All rights reserved.