Development of an electrochemical oxidation process for the treatment of landfill leachates

Abstract

Some landfill site operators use wastewater treatment plants for the discharge of complex leachate waste. However, for the water company involved in managing the wastewater plant, leachates can pose a problem to the quality of the effluent, due to the high levels of Chemical Oxygen Demand (COD), ammonia and inorganic metal constituents. Electrochemical oxidation of landfill leachate has been successfully used by researchers(1,2,3,4) with current densities of 5 to 100 mA/cm2. A new laboratory system has been developed which utilises a low current density of 2.42 mA/cm2 and the performance has been evaluated with synthetic and ’real’ landfill leachates from 2 wastewater sites. This system reduces COD of synthetic mixtures by 58%, with complete removal of ammonia. For real leachates, 5 out of 8 samples resulted in ammonia reduction, with 2 samples experiencing approximately. 60% COD reduction. Power costs for treatment have been determined and the potential for a full-scale installation considered. © 2005 Blackwell Publishing Ltd.