effect of cathode types on long-term performance and anode bacterial communities in microbial fuel cells

effects of cathode types on the long-term stability of microbial fuel cell (mfc) and the anodic microbial communities were studied using k₃fe(cn)₆ catholyte (r1), air cathode (r2) and biocathode (r3) over a testing time of 400 d. upon 400 d of testing, the maximum power densities (p_max) of r1 and r2 decreased by 44% and 37%, and the coulombic efficiencies (ces) decreased 8.4% (r1) and 2.0% (r2), respectively, using the performances on 10 d as the comparison basis. conversely, the p_max and ce of r3 increased by 68.2% and 116.8%, respectively. the non-ohmic resistances (r_no) in all tests were the principal contributors of cell internal resistances. phylogenetic analyses revealed that the microbial communities on anodic surface varied with cathode types and operational history.