Advances and challenges in biocathode microbial electrolysis cells for chlorinated organic compounds degradation from electroactive perspectives

• Published in: The Science of the total environment 2023-12, Vol.905, p.167141-167141, Article 167141
• Main Authors: Lin, Rujing, Xie, Li, Zheng, Xiaomei, Patience, Dzedzemo-on Dufela, Duan, Xu
• Format: Article
• Language: English
• Subjects: biocathodes; biochemical pathways; Bioelectrochemistry; dechlorination; Electrode material; electrolysis; electron transfer; Electron transport process; energy; environment; microbial electrolysis cells; microorganisms; Organochlorine pollution; pollution; Reductive dechlorination; remediation
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2023.167141

Microbial electrolysis cell (MEC) is a promising in-situ strategy for chlorinated organic compound (COC) pollution remediation due to its high efficiency, low energy input, and long-term potential. Reductive dechlorination as the most critical step in COC degradation which takes place primarily in the cathode chamber of MECs is a complex biochemical process driven by the behavior of electrons. However, no information is currently available on the internal mechanism of MEC in dechlorination from the perspective of the whole electron transfer procedure and its dependent electrode materials. This review addresses the underlying mechanism of MEC on the fundamental of the generation (electron donor), transmission (transfer pathway), utilization (functional microbiota) and reception (electron acceptor) of electrons in dechlorination. In addition, the vital role of varied cathode materials involved in the entire electron transfer procedure during COC dechlorination is emphasized. Subsequently, suggestions for future research, including model construction, cathode material modification, and expanding the applicability of MECs to removal gaseous COCs have been proposed. This paper enriches the mechanism of COC degradation by MEC, and thus provides the theoretical support for the scale-up bioreactors for efficient COC removal. [Display omitted] •Electrical stimulation has direct promoting effect on dechlorination.•The provision, transfer and usage of electrons in dechlorination are reviewed.•Improving the performance of MEC hinges on the choice of the electrode material.•The enhancing impact of cathode materials on dechlorination process is summarized.•Recommendations are proposed for adaptive models, cathode material and application.