Porous Carbon Derived from Pumpkin Tissue as an Efficient Bioanode Toward Wastewater Treatment in Microbial Fuel Cells

A novel three-dimensional porous biocarbon electrode with exceptional biocompatibility was synthesized via a facile approach using pumpkin as the precursor. The obtained pumpkin-derived biocarbon features a highly porous architecture and serves as an efficient biocarbon electrode (denoted as PBE) in a microbial fuel cell (MFC). This PBE could form robust biofilms to facilitate the adhesion of electroactive bacteria. When used in the treatment of real wastewater, the assembled PBE-MFC achieves a remarkable power density of 231 mW/m2, much higher than the control (carbon brush—MFC, 164 mW/m2) under the identical conditions. This result may be attributed to the upregulation of flagellar assembly pathways and bacterial secretion systems in the electroactive bacteria (e.g., Hydrogenophaga, Desulfovibrio, Thiobacillus, Rhodanobacter) at the anode of the PBE-MFC. The increased abundance of nitrifying bacteria (e.g., Hyphomicrobium, Sulfurimonas, Aequorivita) and organic matter-degrading bacteria (e.g., Lysobacter) in the PBE-MFC also contributed to its exceptional wastewater treatment efficiency. With its outstanding biocompatibility, cost-effectiveness, environmental sustainability, and ease of fabrication, the PBE-MFC displays great potential for application in the field of high-performance and economic wastewater treatment.