Enhanced performance of microbial fuel cell with polyaniline/sodium alginate carbon brush hydrogel bioanode and removal of COD

The use of capacitive and biocompatible anode materials is important for constructing microbial fuel cells (MFCs). Here, self-supporting polyaniline-sodium alginate/carbon brush (PANI-SA/CB) hydrogel was prepared by in situ polymerization as an MFC anode. The easily fabricated PANI-SA-conducting hydrogels showed great potential as electrode materials for MFC anodes. The maximum power density of MFCs equipped with PANI-SA/CB hydrogel bioanodes was 515 mW/m(2), which was 1.38 times higher than that of the blank CB bioanode (373 mW/m(2)). During the charging-discharging experiment with 30 min of charging and 60 min of discharging, the stored charge Q(s) of the PANI-SA/CB hydrogel bioanode was 1984.42C/m(2), 2.98 times higher than that of the blank CB bioanode (665.88C/m(2)). The robustness of our findings stems from the excellent capacitive properties of PANI-SA. These findings suggest that anode materials, such as the PANI-SA/CB hydrogel anode in MFCs, can function as biocapacitors, as they can simultaneously store electrons generated from microbial oxidation of substrates and release the accumulated charge. (C) 2020 Elsevier Ltd. All rights reserved.