Immobilization of Anodophilic Biofilms for Use in Aerotolerant Bioanodes of Microbial Fuel Cells

The anodophilic bacteria in the anodes of microbial fuel cells (MFCs) used to catalyze carbon oxidation are anaerobes and require anaerobic conditions; their bioelectrocatalytic activity will be greatly suppressed upon direct exposure to O2. In this study, an aerotolerant bioanode was fabricated for the first time by immobilization of anodophilic bacteria for use in MFCs operating under aerobic conditions. The fabrication of the aerotolerant bioanode was realized through the electrochemically induced penetration and propagation of anodophilic bacteria in a three-dimensional hydrogel scaffold. Under the protection of the hydrogel scaffold, the anodophilic bacteria exhibited excellent bioelectrocatalytic activity under continuous O2 aeration and delivered a current density comparable to that under anaerobic conditions. The MFC equipped with the aerotolerant bioanode has the potential to be applied to traditionally aerobic wastewater treatment (WWT) technology. This study offers new insight into the application of MFCs for WWT.