Enhancing Bio‐Electrochemical Removal of Hydrophobic o ‐Dichlorobenzene Through Interfacial Microenvironment Modulation

Bio‐electrochemical process is a promising approach to eliminate chlorinated volatile organic compounds (CVOCs), but the strong hydrophobicity nature of CVOCs inhibits their mass transfer from gas phase toward solid phase (bio‐electrode). Herein, we reported a hydrophobicity‐tunable interfacial microenvironment by modifying perfluoroalkyl acids onto the bio‐electrode to enhance gas‐solid mass transfer. The prepared F n ‐Co 3 O 4 featured with hydrophobicity‐tunable interface, which somewhat enhanced the interfacial enrichment of hydrophobic o ‐DCB and O 2 , with the latter one beneficially triggering metastable Co(IV); meanwhile, the hydrophilic Cl − was repelled from the electrode surface, minimizing the generated toxic chlorinated byproducts. On the other hand, the o ‐DCB/O 2 ‐enriched interfacial microenvironment improved the viability of the Shewanella oneidensis MR‐1, and the abundance of intracellular respiration and mtrABC ‐dominated extracellular electron transfer genes was significantly upregulated. Consequently, F 5 ‐Co 3 O 4 demonstrated the best bacterial‐electric synergism, achieving a remarkable o ‐DCB elimination capacity of 148.06 g·m −3 ·h −1 in a short empty bed residence time of 60 s, outperforming those of state‐of‐the‐art bio‐electrochemical processes reported. This finding highlights the importance of interfacial hydrophobicity microenvironment modulation and reveals a promising way for developing highly efficient bio‐electrochemical systems.