Chelate-modified Electro-Fenton process for mixed industrial wastewater treatment

Abstract

ABSTRACT Mixed industrial wastewater (combined wastewater from small-scale industries) treatment is challenging due to the change in characteristics of the wastewater ( time and quantity). The Electro-Fenton (EF) process is one of the effective techniques for the degradation of organic pollutants from the wastewater, but it works under low pH condition, which is one of the major disadvantages of the EF process. To overcome this disadvantage, the chelate-modified EF process was used in this study. In the chelate-modified EF process, EDTA was used as the chelating agent to form complex with Fe ions and to enhance Fenton reaction at near neutral pH. Ti electrode coated with RuO2 was used as anode and graphite as cathode. The batch reactor was operated by varying initial pH, Fenton reagent dosage and chelating agent dosage. The results demonstrate that the chelate-modified EF process gives effective COD removal (67%) at near neutral pH, as comparable to that of the EF process (66%) at acidic pH. Highlights The Chelate-modified EF process for the removal of COD at near neutral pH Treatment of the mixed industrial wastewater with very low BOD/COD ratio Influence of Fenton catalyst and chelating agent dosage on COD removal. Comparable COD removal of 67% with Chelate-modified EF at near neutral pH and 66% with EF at acidic pH. Mineralization current efficiency and instantaneous current efficiency for COD removal.