多介质人工湿地-微生物燃料电池:不同基质组合对污染物降解协同产电机制影响OA

The constructed wetland-microbial fuel cell(CW-MFC)system developed in this study utilized three types of media—gravel,pyrite,and quartz sand.These media were arranged in layered and mixed configurations to form layered substrate(CW-MFC-L)and mixed substrate(CW-MFC-M)systems.The study investigated the synergistic mechanisms of these two substrate configurations(layered and mixed)on pollutant removal and electricity generation performance in CW-MFCs.Results showed that in the multi-media CW-MFC systems with layered and mixed substrate configurations,the removal rates of total phosphorus(TP)and ammonium nitrogen(NH4+-N)both decreased with increasing influent COD concentration,while COD removal efficiency and electricity generation performance initially increased and then decreased.When the influent COD concentration was 300 mg·L-1,both CW-MFC-L and CW-MFC-M achieved their maximum power densities,at 55.91 mW·m-3 and 52.58 mW·m-3,respectively.The CW-MFC-L system outperformed the CW-MFC-M system in terms of COD and TP removal as well as electricity generation,indicating that the layered substrate configuration is superior to the mixed combination in both pollutant removal and power production.Scanning electron microscopy and microbial community analysis revealed that biofilms and Fe-S compounds formed on the surfaces of the carbon felt and pyrite significantly enriched electrochemically active bacterial communities(such as Proteobacteria and Actinobacteria),whose abundance was positively correlated with system electricity generation performance.This study elucidates the impact mechanisms of substrate configuration on CW-MFC system performance and provides a theoretical basis for enhancing efficiency through optimized substrate combinations.