Increased electroactive species concentration in anodic biofilm of Geobacter-inoculated microbial fuel cells under static magnetic field

摘要

The effects of a static magnetic field (MF) on the electricity production and anodic bioelectrochemical activity in Geobacter sulfurreducens-inoculated microbial fuel cells (MFCs) were investigated. The results showed that application of a MF of 100, 200, and 400 mT improved the electricity generation considerably, with an increase in the maximum power density by 27-100 %. The maximum power density of 0.030 mW cm(-2) was obtained at field strength of 100 mT, representing the best MFC performance with the lowest internal resistance of 453.6 Omega. Electrochemical impedance spectroscopy results showed that the MFC activation resistance was decreased under a MF. The impact of a MF on the bioelectrochemical activity of Geobacter-based biofilm was analyzed by cyclic voltammetry (CV). The redox peak currents of the voltammetric behavior increased in the presence of a MF, indicating enhanced bioelectrochemical catalyzed activity. In addition, evidence from CV revealed higher density of electroactive species in the anodic biofilm with MF than without, leading to a more efficient direct electron transfer process by G. sulfurreducens.