Electrokinetic extraction of lead from kaolinites: II. Experimental investigation

Abstract

This is the second paper of two companion papers presenting the results of laboratory bench-scale experimental studies on electrokinetic extraction of lead from two different kaolinites. The theoretical formulation and numerical simulation of the process are presented in the first paper. Two different kaolinites were used in the study: (1) Georgia kaolinite and (2) Milwhite kaolinite. The lead spiked in Georgia kaolinite was highly mobilized and effectively extracted by the technique as the pH in the soil was significantly lowered by the electrokinetic process. Milwhite kaolinite has a much higher acid/base buffer capacity, and the required acidic environment could not be developed. As a result, removal of the lead spiked in Milwhite kaolinite was minimal. Comparison between simulations and experimental results is also presented. Factors affecting the cleanup efficiency of the process and potential enhancement techniques are also discussed.