Remediation of Dye-Polluted Kaolinite by Combination of Electrokinetic Remediation and Electrochemical Treatment

Abstract

This work studies the removal of organic pollutants from soil applying a combination of the electrokinetic remediation and the electrochemical decolorization. Model samples with kaolinite clay polluted with the dye Lissamine Green B (LGB) were used to evaluate the capability of the electrokinetic remediation in the treatment and removal of organics from soils. Unenhanced electrokinetic treatment did not result in any significant removal of LGB from the kaolinite sample. However, the use of Na₂HPO₄ in the processing fluid increased the electro-osmotic flux, improved the desorption of dye from the surface of kaolinite particles, and prevented the acidification of the medium. After 2 days, 94% of the dye was transported toward the cathode chamber where it was accumulated. Use of Na₂SO₄ in the processing fluid also improved the results compared to the unenhanced experiment but the removal of dye only reached 75% due to the lower electro-osmotic flux registered in this experiment. Once the dye was removed from kaolinite clay sample, the dye Lissamine Green B can be decolorized using electrochemical treatment. The effect of Na₂HPO₄, in the collected liquid, and dye concentration were studied. Na₂HPO₄ clearly improves the decolorization rate reaching high decolorization in a short treatment time.