New in situ soil treatments are needed to remediate soil contaminated with toxic metals. Electrokinetics is an in situ soil remediation technique that involves the transport of contaminants by applying an electric field between electrodes inserted in soil. The method involves no excavation or off-site transportation of contaminated material, and, should be very acceptable to the public in adjacent communities as a remediation method. However, there are considerable technical problems to be overcome before this technique can be considered as an effective means of soil decontamination. The first problem is that during electrokinetic processing the soil pH around the negative electrode (i.e., cathode) rises causing the transport of contaminants to drop and the energy required to drive the process to increase. A second problem is how to achieve efficient contaminant migration through the soil. This proposal describes research to demonstrate the feasibility of two electrochemical innovations that when applied together will eliminate important technical barriers preventing the efficient use of electrokinetic processing for soil remediation. These innovations will prevent high pH at the cathode and will provide a fundamentally new mechanism for achieving rapid contaminant migration in soil. Phase I experiments will be carried out using bench scale systems with natural soils contaminated with heavy metals.
