Electrochemical remediation of phenanthrene from contaminated kaolinite

Abstract

In this work a two-stage process combining soil electrokinetic remediation and liquid electrochemical oxidation for the remediation of polluted soil with organic compounds has been developed and evaluated using phenanthrene-spiked kaolinite. Application of an unenhanced electrokinetic process resulted in negligible removal of phenanthrene from the kaolinite sample. Addition of co-solvents and electrolyte to the processing fluid used in the electrode chambers enhanced phenanthrene desorption from the kaolinite matrix and favoured electro-osmotic flow. Near-complete removal of phenanthrene was achieved using Na2SO4 and ethanol in the processing fluid. Phenanthrene was transported towards the cathode chamber where it was collected. The cathodic solution containing the pollutant was treated by electrochemical oxidation; complete degradation of phenanthrene occurred after 9 h using Na2SO4 as electrolyte.