Impact of different electrode materials on the redox properties of extracellular polymeric substances in electroactive mixed biocommunities.

This study delves deeply into the impact of different electrode materials on the redox properties of extracellular polymeric substances (EPS) within electroactive mixed microbial communities. The experimental results reveal that the redox properties of EPS exhibit significant variations depending on the electrode materials employed. Among them, the reactor (MEC-BTF3) utilizing dual carbon felts as the cathode and anode electrodes demonstrates the most outstanding degradation performance. Within a 96-h reaction period, the degradation efficiency of trichloroethylene (TCE) by this reactor reaches as high as 94.3 %. In-depth analysis indicates that the dual carbon electrodes possess a low charge transfer internal resistance, a characteristic that substantially enhances the electron transfer rate. Moreover, in the protein secondary structure of EPS, the β-sheet structure accounts for 40.0 % of the total amide I region. This structural feature effectively promotes the formation and stability of microbial aggregates. The important findings of this study not only facilitate a more profound understanding of the interaction mechanisms between electrode materials and EPS in electroactive microbial communities but also offer theoretical guidance for the development of more efficient and targeted bioelectrochemical system (BES).