The Factors Affecting Biofilm Formation in the Mediatorless Microbial Fuel Cell

The mediatorless microbial fuel cell (MFC) was constructed with Geobacter metallireducens and the factors affecting biofilm formation and structure were studied using sodium acetate as substrate. The process of biofilm formation was clearly observed by SEM. Current in MFC was mainly generated by the bacteria attached on the anode surface. Experiments showed that the adhesion of Geobacter metallireducens on the anode primarily depended on the chemical bond, rather than the electrostatic force between the bacteria and the anode. Shear force changed the structure of the biofilm, and consequently affected the current generation. The electricity could resume while the open circuit was connected, which demonstrated that the MFC could endure temporary intermittence. In addition, the substrate concentration and the anode surface area were in proportion to electricity