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Groundwater contamination by per- and polyfluoroalkyl substances (PFAS) poses a persistent environmental and public health concern. This study evaluates a two-chambered bioelectrochemical system (BES) inoculated with the West Branch Consortium (WBC-2) for PFAS remediation. Under an applied cathodic potential of -450 mV (versus Ag/AgCl), the BES with active WBC-2 achieved >99.0% perfluorooctanesulfonic acid (PFOS) removal within 21 days in deionized water with culture medium and >98.9% removal of PFOS, perfluorooctanoic acid (PFOA), perfluorohexanoic acid (PFHxA), and perfluorohexanesulfonic acid (PFHxS) in contaminated groundwater after 102 days. Intermediate formation (e.g., PFOA, 6:2 fluorotelomer sulfonate (6:2 FTS), perfluoropropionic acid (PFPrA), perfluorobutanoic acid (PFBA)) and background-corrected fluoride release were consistent with PFOS transformation under anaerobic reducing conditions potentially involving defluorination. Following repeated PFOS spikes (100 µg/L on Days 0, 50, and 399), PFOA, PFPrA, and PFBA accumulated over 664 days. Despite being the dominant accumulated compound, PFOA accounted for <1.8% of the total spiked PFOS mass. Minimal PFOS transformation occurred in controls without active WBC-2, highlighting the importance of microbial metabolism. Biofilm analysis revealed dense colonization of rod-shaped bacteria on carbon fiber brushes. Enrichment of Bacillus, Agrobacterium, and other low-abundance taxa suggests selective adaptation to BES and PFAS conditions. These findings highlight BES driven by electrochemically stimulated microbial activity as a promising strategy for PFAS remediation. 

ABSTRACT ObjectiveThis study aimed to investigate the potential role of cesium chloride (CsCl), ivabradine (IVA), and isoproterenol (ISO) on the sensory transmission of bladder afferents to graded urinary bladder distension (UBD). We specifically selected these drugs to target the hyperpolarization‐activated cyclic nucleotide‐gated (HCN) cation channels to determine their role in afferent encoding. MethodsThe bladders of C57BL/6 female mice were harvested with attached pelvic nerves in continuity, and the stimulus–response function (SRF) of bladder afferents to stepped bladder distension (20, 40, 60, 80 cmH₂O) was recorded by single‐fiber recordings. Their changes in SRF to bath application of CsCl, IVA, and ISO were then evaluated. The presence of HCN on bladder afferent endings was assessed through immunohistological staining on bladder sections from mice with genetically labeled bladder afferents. ResultsIVA and ISO did not significantly reduce afferent responses to UBD, whereas CsCl increased afferent responses. Bladder afferents in the pelvic nerve pathway were categorized into low‐firing (LF, < 10 Hz) and high‐firing (HF, > 10 Hz) groups. SRF in both the LF and HF groups showed similar trends with no significant changes in response to IVA and ISO. CsCl increased SRF only in the HF group but not in the LF group. Immunohistological staining revealed that HCN1 does not extensively co‐localize with afferent endings, showing only sporadic presence. ConclusionOur targeted pharmacological studies with single‐fiber recordings and immunohistological staining collectively suggest that HCN channels do not play a significant role in bladder afferent sensory transmission.