Electrokinetic Remediation of Cadmium-Contaminated Clay |
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Authors: | Albert T. Yeung Cheng-non Hsu |
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Affiliation: | 1Associate Professor, Dept. of Civil Engineering, The Univ. of Hong Kong, Pokfulam Rd., Hong Kong. 2Assistant Professor, Graduate School of Environmental Resources Management, Transworld Institute of Technology, 88 Yan Shan Rd., Douliu, Yunlin, Taiwan.
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Abstract: | Electrokinetic extraction has been demonstrated to be very effective in removing heavy metals from Georgia kaolinite. The relatively high removal efficiency depends on the extremely acidic soil environment generated by the electrokinetic process. However, the efficiency observed in Georgia kaolinite cannot be achieved in soils of high acid/base buffer capacity without enhancement. In this study, the effect of ethylenediaminetetraacetic acid (EDTA) to enhance electrokinetic extraction of cadmium from Milwhite kaolinite was examined. The influence of electro-osmotic flow direction on the migration of cadmium, EDTA, and their complexes were also investigated. It was observed that injection of EDTA from the cathode reservoir by a reverse electro-osmotic flow could mobilize the cadmium in the specimen effectively. A less significant mobilization of cadmium was observed when the electro-osmotic flow was directed toward the cathode. However, accumulation of cadmium near the anode was observed regardless of the electro-osmotic flow direction. |
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Keywords: | Fine-grained soils Electrokinetics Laboratory investigation Sorption Cadmium Soil treatment |
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