Decolorization and power generation in a microbial fuel cell with pomelo peel-derived bioanode

Dye wastewater poses significant environmental risks, and while microbial fuel cells (MFCs) demonstrate excellent decolorization efficiency in treating such wastewater, developing a high-performance anode remains crucial for enhancing MFC performance. This study developed a bioanode—polypyrrole-pomelo peel carbon-carbon cloth (PPy-PPC-CC)—via a facile calcination-carbonization and electrochemical polymerization approach using pomelo peel as biomass material. Physicochemical and electrochemical characterizations revealed that the modified PPy-PPC-CC anode exhibited an enlarged specific surface area with elevated pyrrolic-N content (66.3 ± 1.2 %) and total nitrogen (13.11 %), thereby synergistically enhancing extracellular electron transfer (EET) efficiency. In addition, the MFC equipped with the PPy-PPC-CC bioanode achieved a decolorization efficiency of 94.23 ± 2.12 % at 72 h for methyl orange treatment while achieving a maximum power density of 370 ± 5.3 mW/m². The liquid chromatography coupled with mass spectrometry (LC-MS) analysis revealed two degradation pathways of methyl orange: demethylation and benzene ring hydroxylation. Possible degradation pathways were further proposed based on the identified intermediates. Finally, microbial analysis revealed enriched electroactive genera (Geobacter, Acinetobacter, Enterobacter), optimizing and improving the structure of the anode biofilm community. The results demonstrate that the MFC equipped with the PPy-PPC-CC bioanode exhibits excellent electrochemical performance, good biocompatibility, and remarkable methyl orange decolorization efficiency.