초록
Batch tests were operated to investigate the bioelectrochemical enhancement of methane production from the high-solid anaerobic digestion of waste sludge in the microbial electrolysis cells (MEC) with iron-graphite electrode. Compared with the control tests, methane production in the MEC with iron-graphite electrode increased by 22.4% and VSS removal rate increased by 11% at an applied voltage of 0.3V. However the methane production decreased and hydrogen was cathodically produced when increasing the voltage to 0.6V. At the higher voltage, the excessive utilization of H<SUP>+</SUP> in the cathode led to the alkaline pH to inhibit the methanogenesis. The applied voltages of 0.3V could also enhance the removal of suspended and volatile suspended solids. The input of energy at 0.3V could be neglected compared to the incremental energy generated from the methane. Denaturing gradient gel electrophoresis analysis revealed that the operation at 0.3V had a bioaugmentation effect for both archaea and bacteria in the high-solid anaerobic digestion of waste sludge, which might be useful for enhancing VFA formation and methane production.