Application status and research progress of bioelectrochemical anaerobic digestion system

This review investigated typical research works related to bioelectrochemical anaerobic digestion (BEAD) in the field of biogas production. The configuration and operational principles of the BEAD system were firstly introduced; then, the efficacy and mechanisms of the BEAD system to mitigate process instability and simultaneously to enhance methane generation during anaerobic digestion were discussed; finally, the effects of variable parameters (including applied voltage, electrode material and the spacing of the electrodes) on improvement of the anaerobic digestion system were analyzed. Recent studies revealed that BEAD can enhance methane yield by a factor of 0.15~8.6, and simultaneously the methane content in biogas can also be increased by a factor of 1.2 to 1.6. This improvement can be attributed to the enrichment of functional microorganisms and enhanced electrons transfer efficiency due to adoption of BEAD system, implying that the voltage and electrode material of the BEAD system could be significant parameters on system performance. Nonetheless, full-scale application of the BEAD system encounters economic constraints. Future research work should focus on exploration of intermittent powering, powering by renewable energy, using peak-valley power as supply for the BEAD system. Meanwhile, developing new electrode materials that could enhance microbial enrichment while keep resistant to fouling, and innovating electrode assembly configurations or embedding patterns, are believed to significantly promote the practical applications of BEAD. © 2024 Chinese Society for Environmental Sciences. All rights reserved.