Effect of cyclodextrin on the remediation of hexachlorobenzene in soil by electrokinetic Fenton process

Integration of electrokinetics with chemical oxidation especially Fenton's process is a widely accepted technique for the degradation of organic compounds in soil. This paper presents a study on the effect of cyclodextrin as an enhancing agent during the electrokinetic Fenton process for the remediation of soil contaminated with a hydrophobic organic compound. Kaolin was used as the model clay and was spiked with hexachlorobenzene (HCB) to get an initial concentration of 100 mg/kg. An attempt was made to evaluate the performance of high concentration hydrogen peroxide (H₂O₂) to oxidize the contaminants in the sorbed state in the presence and absence of cyclodextrin. The treatment was carried out for 15 consecutive days. The results clearly demonstrate the efficiency of the process while at the same time, the distribution of the residual contaminant in the soil is greatly influenced by the presence of cyclodextrin. There was no soluble iron addition during the process and the system used the inherent iron in kaolin to catalyze the Fenton-like reactions. A maximum of 76% removal of the contaminant from the soil was observed when 30% H₂O₂ was used in the absence of cyclodextrin.