Electrokinetic cleaning of industrial residues

Abstract

Processing of low grade ores for metal extraction leaves behind a huge mass of residue, which may be disposed by land filling. However, prior removal of toxic heavy metals is imperative to prevent ground water pollution. Electrokinetic remediation used for treating contaminated soils could be adapted for the removal of heavy metals from industrial residues. Preliminary electrokinetic cleaning experiments on dichromate residue showed the feasibility of removal of Cr(VI) from residue along with pH modification. From an initial concentration of 1758 mg kg⁻¹, the concentration of Cr(VI) could be brought down to 615 mg kg⁻¹, besides the drop in pH from 10·9 to 6·8 in 72 h. The residue thus can be a start-up material for other remediation processes such as phytoremediation.