Simultaneous nitrification and denitrification microbial fuel cells (SND-MFC) for nitrogen removal and bioelectricity recovery: a review of performances, mechanisms, microorganisms, and applications.

内容摘要

Complex nitrogen pollution in wastewater and the rising energy consumption are calling for the development of coupled advanced technologies to simultaneously remove pollutants and recover energy. Simultaneous nitrification and denitrification microbial fuel cells (SND-MFCs) enable efficient removal of nitrogen and recovery of energy. This review systematically discusses the latest developments of SND-MFC system under different system designs, including reactor configurations, electrode materials, and critical operating parameters that govern the efficiency of the removal of nitrogen and the generation of power. Meanwhile, mechanisms are firstly analyzed from the points of reacting substances, functional zoning and distribution of electrons. This review also describes microbial synergy among nitrifiers, denitrifiers and electroactive taxa from the points of biofilm's stratification, microbial community, strain screening with metagenomic detection and electron-transfer pathways. Furthermore, characteristics of real wastewater of SND-MFC in coking, pharmaceutical, and livestock wastewater are also summarized, exhibiting comprehensive elimination of nitrogen and recovery of bioelectricity under carbon- and aeration-free conditions. Subsequent research should further optimize the performance of the system by developing intelligent strategies based upon machine learning (ML) and digital twin technologies, electrobiological communication circuits, combination of strain screening and gene editing to unlock the full-scale potential of SND-MFC technology. In addition, the transition from laboratory-scale to practical applications also faces multiple technical challenges that require attention.