Treatment of landfill leachate by a combined anaerobic fluidized bed and zeolite column system

The use of a combined anaerobic fluidized bed and zeolite fixed bed system in sanitary landfill leachate treatment was investigated. Anaerobic treatability studies were successfully performed in the anaerobic fluidized bed reactor. The chemical oxygen demand (COD) removal was attained up to 90% with increasing organic loading rates as high as 18 g COD/L day after 80 days of operation. Good biogas production yield (Y_gas) of 0.53 L biogas per gram removed COD with methane (CH₄) content of 75% was obtained. The attached biomass concentration increased along the column height from bottom to top, and its mean value was found 6,065 mg/L after 100 days of operation. The anaerobically treated landfill leachate was further treated by a zeolite fixed bed reactor. While excellent ammonia removal (>90%) was obtained with the untreated zeolite, the regenerated zeolites showed higher performance. Consequently, this combined anaerobic and adsorption system is an effective tool to remove high COD and high ammonia in landfill leachate. Journal of Environmental Engineering