Curbing per- and polyfluoroalkyl substances (PFASs): First investigation in a constructed wetland-microbial fuel cell system

The presence of per-and polyfluoroalkyl substances (PFASs) in water environments has been linked to a slew of negative health effects in both animals and humans, but the green and eco-sustainable removal technologies remain largely unknown. Constructed wetland coupled microbial fuel cell (CW-MFC) is termed a green process to control pollutants and recover energy. However, so far, no study has investigated the removal of PFASs and their effects on the performance of the CW-MFC systems. Here, we investigated the removal performance of PFOA and PFOS in the CW-MFC systems both in the absence and presence of electricity circuit, and explored the distribution and fate of PFASs and their interactions with other elements in the systems. Our findings demon-strated excellent removal efficiency of >96% PFOA and PFOS in CW-MFC systems. PFOA and PFOS were distributed throughout the system via wastewater flow, while electrode material and plants are the main enrichment sites in which MFC enhanced up to 10% PFASs removal. However, a loss of 7.2-13.5% of nitrogen removal and a decrease of 7.3% in bioelectricity output were observed when PFASs were introduced in the system. The driven force led to the loss of nitrogen removal and bioelectricity generation lies in the accumulation of PFASs in system composition, which affected microbial activity and community composition, damaging the health of the plant, and in turn reducing CW-MFC's functioning. No doubt, CW-MFC systems provide an alter-native technique for PFASs removal, alleviating some limitations to the physical and chemical techniques, but further investigation is highly needed.

Automated summary

This study investigated the removal of PFOA and PFOS in constructed wetland coupled microbial fuel cell (CW-MFC) systems and their interactions with other elements. The results showed that the CW-MFC systems achieved a removal efficiency of over 96% for PFOA and PFOS, which were distributed throughout the system via wastewater flow and enriched in the electrode material and plants. However, the introduction of PFASs in the system led to a decrease in nitrogen removal and bioelectricity output, attributed to the accumulation of PFASs affecting microbial activity and community composition, damaging plant health, and impairing CW-MFC functioning.