Electrokinetic Soil Remediation Using Novel Electrodes and Modulated Reverse Electric Fields

Soil contamination is a widespread problem in the United States with more than 4,500 sites currently on the EPA’s national priorities list for clean up. The remediation of heavy metal contamination is particularly urgent due to the high levels of contamination and toxicity. This paper describes the investigation into a novel, two-fold approach to electrokinetic remediation of soils contaminated with heavy metals. Modulated reverse electric fields, in conjunction with integrated ion exchange (IIXTM) electrodes, are being used to (a) induce a more uniform and enhanced remediation of heavy metal contaminated soils, and (b) eliminate the non-uniform pH profile encountered in conventional electrokinetics, by acidification of the soil surrounding the cathode. Concentration of the heavy metal contaminants from the soil into the IIXTM electrode eliminates the need for soil excavation and further treatment. The heavy metals absorbed into the IIXTM electrodes can be recovered, resulting in regeneration of the electrodes, which can then be reused in the soil treatment process.