Synergistic advancements in sewage-driven microbial fuel cells: novel carbon nanotube cathodes and biomass-derived anodes for efficient renewable energy generation and wastewater treatment

Microbial fuel cells (MFCs) offer a dual solution of generating electrical energy from organic pollutants-laden wastewater while treating it. This study focuses on enhancing MFC performance through innovative electrode design. Three-dimensional (3D) anodes, created from corncobs and mango seeds via controlled graphitization, achieved remarkable power densities. The newly developed electrode configurations were evaluated within sewage wastewater-driven MFCs without the introduction of external microorganisms or prior treatment of the wastewater. At 1,000 degrees C and 1,100 degrees C graphitization temperatures, corncob and mango seed anodes produced 1,963 and 2,171 mW/m2, respectively, nearly 20 times higher than conventional carbon cloth and paper anodes. An advanced cathode composed of an activated carbon-carbon nanotube composite was introduced, rivaling expensive platinum-based cathodes. By optimizing the thermal treatment temperature and carbon nanotube content of the proposed cathode, comparable or superior performance to standard Pt/C commercial cathodes was achieved. Specifically, MFCs assembled with corncob anode with the proposed and standard Pt/C cathodes reached power densities of 1,963.1 and 2,178.6 mW/m2, respectively. Similarly, when utilizing graphitized mango seeds at 1,100 degrees C, power densities of 2,171 and 2,151 mW/m2 were achieved for the new and standard cathodes, respectively. Furthermore, in continuous operation with a flow rate of 2 L/h, impressive chemical oxygen demand (COD) removal rates of 77% and 85% were achieved with corncob and mango seed anodes, respectively. This work highlights the significance of electrode design for enhancing MFC efficiency in electricity generation and wastewater treatment.

Automated summary

Microbial fuel cells offer a dual solution of generating electrical energy from organic pollutants-laden wastewater while treating it. The study focuses on enhancing MFC performance through innovative electrode design. Three-dimensional anodes made from corncobs and mango seeds achieved remarkable power densities. Advanced cathodes composed of an activated carbon-carbon nanotube composite were introduced, rivaling expensive platinum-based cathodes. The work highlights the significance of electrode design for enhancing MFC efficiency in electricity generation and wastewater treatment.