Electrodialytic remediation of soil polluted with copper from wood preservation industry

Electrodialytic soil remediation is a newly developed method for removal of heavy metal from polluted soil. The method is based on a combination of the electrokinetic movement of ions in soil with the principle of electrodialysis. The principle was tested in six experiments using laboratory cells on a copper-polluted Danish loamy sand. The duration of the experiments was varied, and the development of concentration profiles in the soil after the remediation was investigated for two different dc currents (0.1 and 0.2 mA/ cm(2) of soil). The rate of Cu removal was about doubled when doubling the current. It was found that Cu content was reduced to a level below 100 mg of Cu/kg of dry soil in the section closest to the anode and that the Cu removed was accumulated in the next section in the direction of the cathode. The accumulation zone was moving in the direction of the cathode during the application of an electric current. When the remediation ended, all Cu could be found in the cathode compartment, and results showed that it was possible to decontaminate the soil from 1360 to below 40 mg of Cu/kg of dry soil.