A specific configuration of circulation-enhanced electrokinetics (CEEK) to remediate real-site Cd and Pb contaminated soils

This study applied circulation-enhanced electrokinetics (CEEK) technique to remove Cd and Pb from the real-site contaminated soils. Soil samples were collected in certain polluted agricultural land in Yunlin, Taiwan. The CEEK system mainly composed of a reactor fulfilling soil samples, one pair of electrodes, a circulation system of working solution and DC power supply. Results demonstrate that the real-site Cd and Pb contaminated soils can be effectively treated by the CEEK technique; the removal efficiency of Cd and Pb can reach 91% and 85%, respectively. The CEEK system can maintain relatively neutral pH of treated soils. The bonding patterns of heavy metals and H+ produced on the anode play the critical roles for removal efficiency. The recovery efficiency of Cd and Pb in the CEEK system can reach 85% and 70%; the species of recovered heavy metals is Cd(OH)2 and Pb5O8, respectively.