Biogas Generation from the High-Strength Fresh Leachate using Anaerobic Continuous Stirred-tank Reactor

Abstract

Lab-scale anaerobic continuous stirred-tank reactor (CSTR) treating fresh leachate from solid waste transfer station was operated by varying organic loading rate (OLR) from 1 to 20 kg.COD/m3.d. The fresh leachate contains chemical oxygen demand (COD) of 100,184 mg/l, BOD5 of 71,000 mg/l., and pH of 3.00-4.36. During the operation of CSTR, organic (COD) removal efficiency was 75-80%. When OLR increased to 15 kg.COD/m3.d, the presence of volatile fatty acid (TVA) became unstable. The organic content in sludge was found varied in the range of 0.45-0.75. Average biogas production in the CSTR was 58.55 L/d with highest methane content of 68 % achieved at an OLR of 10 kg.COD/m3.d. This study demonstrates a possibility of treating high-strength fresh leachate in single-stage CSTR for energy recovery.