Simultaneous removal of chlorobenzene and Cr(VI) from groundwater using microbial fuel cell with low-cost Si modified ferrihydrite electrodes

[Display omitted] •SiFh modified electrodes achieved superior chlorobenzene and Cr(VI) removal in MFC.•CF-SiFh loaded MFC exhibited highest power generation and EET in anode.•Cupriavidus and Pandoraea dominated in chlorobenzene oxidation.•Cr(VI) was reduced to Cr(OH)3 or CrxFe1-x(OH)3 coprecipitates at cathode. Aromatic chlorinated compounds and Cr(VI) in groundwater pose significant challenges due to their resistance. This study explores microbial fuel cells using low-cost Si-modified ferrihydrite (SiFh) electrodes for simultaneous chlorobenzene and Cr(VI) removal. The voltage output of MFC assembled with SiFh modified electrode was approximately 1.63 times higher than the bare electrode, achieving 1.23 times higher in chlorobenzene degradation efficiency. CF-SiFh loaded MFC had the highest power generation and best EET efficiency, which was positive to greatest and fastest chlorobenzene removal. Microbial community analysis identified the dominance of Cupriavidus and Pandoraea in chlorobenzene oxidation, while Lentimicrobiaceae and Rhodobacteraceae were key genera that may facilitate direct and indirect electron transfer within the biofilms. Cr species analysis in solution and solids confirmed it was reduced to Cr(OH)3 or CrxFe1-x(OH)3 coprecipitates at cathode. MFCs with SiFh-modified electrodes thus offer a promising technology for simultaneous chlorinated compound and Cr(VI) removal, promising in contaminated groundwater remediation.