Landfill leachate treatment by the combination of physico-chemical and electrochemical methods

Leachate originating in landfills, where industrial solid wastes are disposed of, is a complex wastewater that could exert high environmental impact. In this paper, treatment of landfill leachate, particularly removal of chemical oxygen demand (COD) through adsorption, chemical oxidation (KMnO4), electrocoagulation and electrochemical oxidation processes was studied. The combined processes, viz. KMnO4 and hypo, electrocoagulation and KMnO4, electrocoagulation and hypo, adsorption and KMnO4, adsorption and hypo were also investigated and the comparison was studied. The treatment of landfill leachate by electrochemical oxidation was carried out in a batch electrolytic parallel plate (Stainless Steel (SS)// Carbon) and fixed bed three dimensional electrode reactor using granular activated carbon as particle electrode. The removal of COD obtained was 8.9% by electrocoagulation, 12.3% by KMnO4, 12.7% by adsorption and 22.2% by electrochemical oxidation using parallel plate electrode reactor. A maximum of 78.2% COD reduction was achieved by electrochemical oxidation in three dimensional electrode carbon bed reactor. The electrooxidation of leachate in three-dimensional electrode reactor required less electrical energy compared to parallel plate configuration. It was inferred that the use of three-dimensional electrode reactor can have more practical advantages.