Impact of Fe(III) as an effective electron-shuttle mediator for enhanced Cr(VI) reduction in microbial fuel cells: Reduction of diffusional resistances and cathode overpotentials

Efficient In Situ Utilization of Caustic for Sequential Recovery and Separation of Sn, Fe, and Cu in Microbial Fuel Cells

“…Stainless steel mesh with small opening size of 120‐mesh in the air‐cathodes diminished metal recovery, compared to results with the 42‐mesh cathodes. In terms of metal recovery and separation, the importance of external resistance and cathode oxygen permeability, as shown in this study, have been largely overlooked in previous studies . Thus, this current study provides better strategies to improve the performance of MFCs as an efficient technology for metal recovery and separation from stripping solutions from PrCB manufacturing.…”

“…In previous studies, most of the metals removed have been reductively deposited rather than chemically precipitated on the cathode ,,,− The separation of Sn, Fe and Cu metals on the electrodes of MFCs represents a challenge for the practical applications of this technology.…”

“…Anodes were fully pre‐acclimated by used MFCs for one month at a fixed external resistance of 1000 Ω . The anolyte (pH=5.8) contained 1.0 g/L sodium acetate dissolved in a phosphate buffer solution (5 mM NaH 2 PO 4 ) that was amended with 12.5 mL/L minerals and 5 mL/L vitamins ,. A synthetic PrCB waste stripping solution composed of Sn(II) of 80 mg/L, Fe(II) of 40 mg/L and Cu(II) of 60 mg/L was used as initial catholyte influent.…”

“…Electrical impedance spectroscopy (EIS) analysis was conducted at cathode potentials under OCCs with either the bare electrodes, or the electrodes deposited with the metal precipitates. EIS frequency ranged from 100 kHz to 10 mHz, with a sinusoidal perturbation of 10 mV amplitude ,,. The equivalent circuits and detailed values of different resistances were obtained through Zsimpwin software and normalized to the projected area of the cathodes.…”

“…A microbial fuel cell (MFC) is an emerging technology that has garnered tremendous attention for its ability to simultaneously treat wastewater and produce electrical power . Compared to aqueous catholyte in MFCs using single or mixed metals as final electron acceptors, including Cu(II), Cr(VI), V(V), Cd(II), W(VI) and Mo(VI), air‐cathode MFCs are more promising systems due to higher power production and coulombic efficiency (CE) as well as more sustainability of oxygen as a oxidizer at the cathode ,,,. The use of a passive air‐cathode requires less energy input for oxygen reduction at the cathodes that use dissolved oxygen, due to the high energy demands needed for air sparging ,,,.…”