[Electricity generation of surplus sludge microbial fuel cell enhanced by biosurfactant]

The effect of biosurfactant (rhamnolipid/TSS, 0.3 g x g(-1)) on the characteristics of electricity generation by surplus sludge microbial fuel cell (SSMFC) and the reduction of surplus sludge were discussed. In the control group, the electrogenesis cycle was 20 d, the maximal power density was 236.84 mW x m(-2), the coulomb efficiency was 5.7%, and the TCOD, TSS and VSS removal efficiency was 58.5%, 56.7% and 66.3%, respectively. In the experimental group, the electrogenesis cycle was 35 d, the coulomb efficiency was 11.8%, the maximal power density was 516. 67 mW x m(-2) which was increased by 118. 15% as compared to the control group, and the TCOD, TSS and VSS removal efficiency was 58.5% , 56.7% and 66.3%, which raised by 104.5%, 96.2% and 98.5% as compared to the control group, respectively. With the operation of the system, the output voltage of control group and experimental group kept stable for a period of time before gradually reduced, the SCOD, protein and soluble sugar concentrations of surplus sludge first increased and then decreased. This study demonstrated that the addition of rhamnolipid enhanced the electricity generation of SSMFC with simultaneous promotion of sludge reduction.