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/m 2 , much higher than the control (carbon brush—MFC, 164 mW/m 2 ) 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.