Effects of the presence of nanoscale zero-valent iron on the degradation of polychlorinated biphenyls and total organic carbon by sediment microbial fuel cell.

The degradation of polychlorinated biphenyls (PCBs) and total organic carbon (TOC) by sediment microbial fuel cell (SMFC) with/without nanoscale zero-valent iron (NZVI) addition was investigated. It was found that the combined application led to the highest removal efficiencies of PCBs (37.55 ± 1.11%) and TOC (49.72 ± 1.54%) in all circumstances and produced a higher power density (108.89 mW/m2) and a corresponding lower internal resistance (264 Ω) than operation employing SMFC only. The TOC removal efficiency and the total production of electricity were linear. High-throughput sequencing of anodic microbial communities indicated that the electrode participation can increase the abundance of electrogenic bacteria (Geobacter and Pseudomonas) and the NZVI addition can reduce the oxidation reduction potential of the system and therefore enrich some bacteria (Longilinea and Desulfofustis) beneficial to the degradation of organic matter.