Treatment of landfill leachate using granular multi-stage anaerobic reactor: optimisation through response surface methodology

Abstract

One of the most hazardous sources of pollution these days is landfill leachate. This harmful wastewater is not only affecting the environment, but also the health of beings surrounding the landfills. Numerous treatments have been used to treat this recalcitrant wastewater; however, anaerobic treatment has been in focus in recent years. In this study, we investigated the interactive effects of chemical oxygen demand (COD), leachate percentage and pH on the performance of a granular multi-stage anaerobic reactor (GMSAR) treating landfill leachate. Response surface methodology (RSM) was utilised to project the interaction effects of the operating conditions of the treatment system in terms of COD removal and biogas yield. The optimum region of the GMSAR was acquired at influent COD of 1239 mg/L, a leachate percentage of 14.2% and a pH of 7.3. These variables resulted in a 71.9% COD removal and 65.9mL/d of biogas yield. The percentage of leachate and COD influent resulted respectively in the most effective parameters on the COD removal and biogas yield of GMSAR.