Removal of lead from a silt loam soil by electrokinetic remediation

In this study, a silt loam soil spiked with lead (ca. 1000 mg/kg) was treated by electrokinetics using an electric gradient of 1 V/cm. In all tests, 0.1 M acetic acid was used as the cathode reservoir fluid. However, anode reservoir fluids used were 0.1 M of acetic acid, citric acid, ethylenediaminetetraacetic acid (EDTA), respectively. Experimental results have shown that the electroosmotic (EO) flow in a direction towards the cathode would be reversed if the system pH is less than the point of zero charge (PZC) of the soil particles. Besides, the pH of both electrode reservoirs were found to be important to the removal of lead ions from soil. Experimental results have also shown that using acetic acid, citric acid, and EDTA as anode reservoir fluids resulted in lead removal efficiencies of 27.6%, 53.3%, and 11.2%, respectively.