Iron Oxide–Modified Carbon Electrode and Sulfate-Reducing Bacteria for Simultaneous Enhanced Electricity Generation and Tannery Wastewater Treatment

Abstract

The microbial fuel cell (MFC) is emerging as a potential technology for extracting energy from wastes/wastewater while they are treated. The major hindrance in MFC commercialization is lower power generation due to the sluggish transfer of electrons from the biocatalyst (bacteria) to the anode surface and inefficient microbial consortia for treating real complex wastewater. To overcome these concerns, a traditional carbon felt (CF) electrode modification was carried out by iron oxide (Fe3O4) nanoparticles via facile dip-and-dry methods, and mixed sulfate-reducing bacteria (SRBs) were utilized as efficient microbial consortia. In the modified CF electrode with SRBs, a considerable improvement in the bioelectrochemical operation was observed, where the power density (309 ± 13 mW/m2) was 1.86 times higher than bare CF with SRBs (166 ± 11 mW/m2), suggesting better bioelectrochemical performance of an SRB-enriched Fe3O4@CF anode in the MFC. This superior activity can be assigned to the lower charge transfer resistance, higher conductance, and increased number of catalytic sites of the Fe3O4@CF electrode. The SRB-enriched Fe3O4@CF anode also assists in enhancing MFC performance in terms of COD removal (>75%), indicating efficient biodegradability of tannery wastewater and a higher electron transfer rate from SRBs to the conductive anode. These findings demonstrate that a combination of the favorable properties of nanocomposites such as Fe3O4@CF anodes and efficient microbes for treating complex wastes can encourage new directions for renewable energy–related applications.

Impact of CeO2 modified cathode and PANI modified anode on tannery wastewater fed microbial fuel cell performance

“…The surface-modified electrodes were subsequently dried for 24 hrs in the oven at 60 °C. By measuring the difference in the weight of electrodes before and after the coating process, the quantity of CeO 2 that was deposited on the surface of CeO 2 @CC was determined, indicating that CC had a high potential for CeO 2 coating ( Miran et al, 2021 ).…”

Untreated vs. Treated Carbon Felt Anodes: Impacts on Power Generation in Microbial Fuel Cells

“…For instance, a study by Simeon et al highlighted the combined effects of electrode material, spacing, and substrate feeding frequency on MFC performance [12]. Another study by Miran et al emphasized the role of iron oxide-modified carbon electrodes in tandem with sulfate-reducing bacteria for efficient bio-electricity generation [13]. Fatima and colleagues integrated a novel lignin-based carbon fiber felt bioanode in an MFC, demonstrating its potential for treating recalcitrant textile wastewater [14].…”