Deciphering interactive synergy of electron-transfer characteristics for optimal microbial fuel cell-steered dye decolorization

Background: Although simultaneous dye decolorization and bioelectricity generation (SDD&BG) in microbial fuel cells (MFCs) were mentioned in literature, the unpredictable electron-transferring phenomena (ETP) taken place in the cathodic chamber (CC) and anodic chamber (AC) were still remained open to be explored for system optimization. Methods: Double chamber (DC)-MFC were constructed as descried in Guo et al. (2019) for comparative assessment. CC contained 200 mL cultured broth at 0.5x LB broth (OD600-1.6 0.1) and different concentrations of K3Fe(CN)6 at 0, 1000, 3000, 5000 mg L - 1 were specifically provided in 0.01 M phosphate buffered saline. For comparative evaluation, the experimental design of case-control MFC study was implemented via three modes of operation (i.e., dye decolorization (DD) alone, bioelectricity generation (BG) alone and simultaneous DD&BG) in DC-MFC to disclose efficiencies of ETP. Significant findings: This novel study quantitatively deciphered ETP in CC and AC to optimize not only bioelectric generation, but also dye decolorization. Supplement of cathode acceptors (e.g., potassium ferricyanide; PF) in the CC could efficiently augment the overall stoichiometric ratio of electron transfer f value (ca. 3.34-3.46 fold increase), considerably stimulating the performance of reductive decolorization. Evidently, DC-MFC seemed to be more electroactive than single chamber-MFC to maximize ET efficiency for SDD&BG. (c) 2021 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

Automated summary

This study quantitatively deciphered the electron-transferring phenomena (ETP) in CC and AC to optimize bioelectric generation and dye decolorization. Supplementing cathode acceptors in the CC efficiently increased the stoichiometric ratio of electron transfer f value, significantly enhancing reductive decolorization performance. DC-MFC appeared to be more electroactive than single chamber-MFC for maximizing ET efficiency in SDD&BG.