Article

Enhancement of Electrokinetic Decontamination with EDTA

Department of Civil & Construction Engineering, Southern Polytechnic State University (SPSU), Marietta, Georgia, USA.
Environmental Technology (Impact Factor: 1.61). 04/2012; 33(20):2291-2298. DOI: 10.1080/09593330.2012.665493

ABSTRACT The effect of ethylenediaminetetraacetic acid (EDTA) during electrokinetic decontamination (EKD) was investigated in this research. EDTA is a ligand that can form soluble complexes with precipitated heavy metals inside soil pores. Millpond sludge, primarily contaminated with lead (Pb) and zinc (Zn), was subjected to EKD with and without the presence of EDTA. Dilute EDTA solutions with strengths of 0.05M and 0.125M were injected into the millpond sludge by electroosmosis. Several beneficial effects of using EDTA were observed in this research: EDTA substantially increased the electroosmotic (EO) flow in the millpond sludge indicating that it could significantly reduce the duration of EKD. Another advantage was that a significantly higher percentage of Pb and Zn removal was achieved from the solid phase due to the complexation of EDTA with these heavy metals. Also, EDTA was able to prevent the precipitation of metals at the cathode electrode typically observed in EKD process.

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