ELECTRONIC (EK) REMEDIATION OF A CONTAMINATED SOIL AT SEVERAL PB CONCENTRATIONS AND APPLIED VOLTAGES

The in situ remediation of a lead-contaminated silt loam by electrokin etic (EK) soil flushing was studied. Two initial soil Pb concentration s (150 and 1000 mg/kg of Pb) and applied voltages (30 and 60 V) were i nvestigated. The EK soil flushing process was less efficient for the 1 50 mg/kg of Pb soils despite these tests being operated for longer dur ations, having larger EO flows and energy inputs, and lower soil pHs. The decrease in effectiveness was attributed to a larger average metal -soil binding energy for the lower contaminated soil. Increasing the v oltage increased the EO flow, current, energy input (kW-hr/kg of soil) , and provided a more evolved low pH front, resulting in more soil bei ng remediated. There appeared to be a correlation between the amount o f EO flow and the desorption and transport of soil-bound lead. Because complete soil remediation did not occur in any of the tests, the fina l energy input per kilogram of soil could not be calculated.