An energy-efficient Magneĺi phase Ti 4 O 7 reactive electrochemical membrane (REM) was applied for the oxidation of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). Approximately 5-log removal of these compounds was achieved in a single pass through the REM with residence times of ∼11 s at 3.3 V/SHE for PFOA and 3.6 V/SHE for PFOS. The permeate concentrations of PFOA and PFOS were <86 and 35 ng L −1 , from initial concentrations of 4.14 and 5 mg L −1 , respectively. The highest removal rates were 3415 ± 203 μmol m −2 h −1 for PFOA and 2436 ± 106 μmol m −2 h −1 for PFOS at a permeate flux of 720 L m −2 h −1 (residence times of ∼3.8 s). The levels of energy consumption (per log removal) to remove PFOA and PFOS to below the detection limits were 5.1 and 6.7 kWh m −3 , respectively. These values are the lowest reported for electrochemical oxidation and approximately an order of magnitude lower than those reported for other technologies (i.e., ultrasonication, photocatalysis, vacuum ultraviolet photolysis, and microwave−hydrothermal decomposition), demonstrating the promise of the REM technology for water treatment applications.

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