A CeO2 sprinkled graphitic novel packed bed anode-based single-chamber MFC for the treatment of high organic-loaded industrial effluent in upflow continuous mode

Abstract

Microbial fuel cells (MFCs) are considered to be an efficient green technology for treating wastewater effluents. The integration of MFCs with an effluent treatment plant can reduce the operational cost and boost up bioelectricity generation. In the current study, a unique conical configuration of a membraneless single-chamber MFC is proposed for use in continuous mode. The MFC is based on cerium oxide (CeO₂) sprinkled carbon nanofibers (CNFs) grown over activated carbon fabric (ACF) as the air cathode and activated carbon beads (ACBs) as the anode. The anode material (CeO₂-CNF/ACBs) packed in a conical chamber facilitates a uniform upflow of water and a dense growth of a biofilm. The air-side of the cathode material (CeO₂-CNF/ACF) is coated with polydimethylsiloxane, whereas the anolyte side is coated with a laboratory-synthesized crosslinked copolymer to facilitate the permeation of atmospheric oxygen and proton exchange, respectively. The MFC operated at a hydraulic residence time of ∼51 min shows a chemical oxygen demand removal efficiency of 76.0 ± 2.0%, generating an open-circuit potential, maximum power density and limiting current density of 0.34 V, 426 mW m⁻³, and 4700 mA m⁻³, respectively. The data indicate that the specially designed MFC with its distinctly configured (disk and beads) electrodes in this study is scalable to treat wastewater in continuous mode and also capable of simultaneously generating high bioelectricity.