Anaerobic sequencing batch reactor treatment of landfill leachate

Anaerobic treatability of municipal landfill leachate was evaluated using lab-scale anaerobic sequencing batch reactors (ASBR) at 35 degrees C. Experimental studies were conducted at wide-range of volumetric (0.4-9.4 g COD l(-1) d(-1)) and specific (0.2-1.9 g COD g(-1) VSS d(-1)) loading rates by varying hydraulic retention times (HRT) (10-1.5 days) and influent wastewater COD's (3800-15900 mg l(-1)). The COD removal efficiencies were in the range of 64-85% depending on volumetric and specific loading rates applied. The net daily biomass conversion yields were about 0.1 g volatile suspended solids (VSS) per g of COD removed. Bacterial decay rate constant was 0.01 d(-1). The maximum volumetric methane production rate (VMPR) of 1.85 I CH4 l(-1) d(-1) was achieved at the volumetric loading rate of 9.4 g COD l(-1) d(-1). The specific methane production rates in terms of COD were about 1.06 g CH4-COD g VSS-1 d(-1) in the reactor. The results have shown that about 83% of COD removed during the treatment was converted to methane. The average biomass yield was determined as 0.12 g VSS per gram of COD removed. (C) 1999 Elsevier Science Ltd. All rights reserved.