Simultaneous Electricity Production and Sludge Treatment Using Two Chambers Microbial Fuel Cells

摘要

Sewage sludge, an important organic waste, was a by-product of biological wastewater treatment. Batch tests were carried out to study simultaneous electricity production and sludge treatment using two chambers microbial fuel cells (MFCs). The sewage sludge samples were added into two chambers of MFC with same concentration for anaerobic digestion and aerobic digestion. The experimental results indicated that it was possible to simultaneously produce electricity and reduce sludge TS and VS using two-chambers MFC from sewage sludge. The electricity production could last long time (about 20 d~30 d) because the hydrolysis of sewage sludge could release the organics from microbial cells of sludge. At stable operation, the MFC with bigger electrodes produced higher voltages and lower power densities than that with less electrodes. The maximal power density achieved was 37.36 mW/m2 using 7.741 g/L sludge (VS) and the maximal open circuit potential of the MFC could reach 0.81 V. The internal resistances of these MFCs were higher than those of similar researches. Bigger electrode led to higher OCV, lower internal resistance and higher maximal power density. Furthermore, the OCVs and the internal resistances of MFCs decreased with the running of MFCs, while maximal power densities of MFCs were just contrary. The experimental results suggested that protein may played an important role in the electricity production of sewage sludge. After the MFC worked 31 d, the TS removal and VS removal of sludge in the anode chambers of two MFCs reached 22-25% and these in the cathode chambers of two MFCs reached 43-52%.