Pulsed EC Electric Fields for Heavy Metal Decontamination of Soil

The removal of heavy metals and/or radionuclides from contaminated subsurface soils and groundwaters is an expensive and time-consuming part of any contaminated site-cleanup process. Development of new techniques for soil remediation is particularly needed for contaminated sites on which nuclear facilities are located. Many remediation methods investigated have been found to be less than satisfactory due to a combination of their short- and/or long-term ineffectiveness, low removal rates of toxic elemental species and high implementation costs. Decontamination of soil using pulsed DC electric fields is a new novel approach for hazardous waste site remediation based on electrochemically induced transport of contaminants through the soil. This technique has the potential to be effective in facilitating the removal of certain types of hazardous wastes from soils, particularly heavy metals. The objective of this proposal is to evaluate the feasibility of electrochemically based remediation technology for removal of heavy metal contaminants from soil and to implement an innovative approach based on the application of pulsed DC electric fields, in combination with periodic pumping. It is anticipated that increasing the turbulence in the soil/contaminant/water system, both by application of an "electrochemical stirring" of the soil and by forced hydraulic flow, will increase the rate of removal of contaminants. Different long-term pulsing-type regimes, including increasing voltage amplitudes and voltage reversals, combined with intermittent pumping, will be investigated in order to enhance the effectiveness of the electrochemically based remediation process.