Long-term bioelectricity generation in microbial fuel cell exposed to perfluorooctanoic acid

The long-term performance of microbial fuel cells (MFCs) depends on microbial communities whose composition strongly influences electron transfer and substrate utilization. The presence of environmental pollutants can cause changes in microbial abundance and biodiversity and have an effect on the MFC efficacy; however, their long-term operational stability under environmental stress remains insufficiently explored. This study assessed the long-term performance of MFCs using river sediment organic matter as the energy, electron, and carbon source during exposure to perfluorooctanoic acid (PFOA). The MFC-PFOA (MFC with PFOA) system operated effectively for 10 months, achieving a maximum voltage of 461.9 mV and a peak current density of 14.5 mA/m², significantly outperforming the control cell. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis confirmed a 94.9 % reduction in PFOA concentration and detected perfluoroheptanoic acid (PFHpA) and perfluorohexanoic acid (PFHxA), indicating possible partial transformation and/or redistribution processes within the bioelectrochemical system. Additionally, bacterial community analysis revealed a shift in microbial composition, with Firmicutes and Desulfobacterota becoming dominant, suggesting their roles in current generation and biotransformation of PFOA. Overall, this work demonstrates long-term bioelectricity generation in the presence of per- and polyfluoroalkyl substances (PFAS) pollutants, while indicating partial attenuation and compositional changes of PFOA under bioelectrochemical conditions, thus providing valuable insights into the robustness of bioelectrochemical systems for energy recovery in contaminated environments.