Effect of anode modification on the performance of microbial fuel cell for dealing with the straw hydrolysate

A microbial fuel cell (MFC) was built with corn stalk hydrolysis solution as the anode substrate and activated sludge source bacteria as the anode microbes. The anode carbon felt (blank CC) was modified by various methods such as HNO₃ acid treatment (HNO₃/CC), chitosan modification (chitosan/CC) and layer-by-layer self-assembly (PDADMAC/α-Fe₂O₃/CC); the effect of anode modification on the performance of MFC in electricity generation was investigated. The results indicate that with blank CC, HNO₃/CC, chitosan/CC and PDADMAC/α-Fe₂O₃/CC as the anode materials, the maximum electricity outputs of MFC are 248, 315, 452 and 522 mV, respectively, the maximum power densities are 54.6, 92.7, 203.8 and 248.1 mW/m², respectively, and the COD removal rates are 82.21%, 81.46%, 82.53% and 86.44%, respectively. Moreover, PDADMAC/α-Fe₂O₃/CC exhibits the highest redox potential according to the CV curves and minimum polarization resistance (7 Ω) as determined by the EIS curves. As a result, the performance of MFC with four anodes follows the order of PDADMAC/α-Fe₂O₃/CC > chitosan/CC > HNO₃/CC > blank CC.