Search Result
Technology Innovation News Survey Feed (RSS)
DEGRADATION OF PERFLUOROOCTANESULFONATE BY REACTIVE ELECTROCHEMICAL MEMBRANE COMPOSED OF MAGNELI PHASE TITANIUM SUBOXIDE
Shi, H., Y. Wang, C. Li, R. Pierce, S. Gao, and Q. Huang.
Environmental Science & Technology 53(24):14528-14537(2019)
PFOS degradation by a reactive electrochemical membrane (REM) system utilizing a porous Magneli phase titanium suboxide ceramic membrane that served simultaneously as an anode was tested. The system removed ~98.3% of PFOS under a cross-flow filtration mode at the anodic potential of 3.15 V versus a standard hydrogen electrode. PFOS removal efficiency during the REM operation was higher than that of the batch operation mode under the same anodic potential. A systematic reaction rate analysis in combination with electrochemical characterizations quantitatively elucidated enhanced PFOS removal in REM operation in relation to the increased electroactive surface area and improved interphase mass transfer. PFOS appeared to undergo rapid mineralization to CO2 and F-, with only trace levels of PFCAs (C4-C8) identified as intermediate products. Density functional theory simulations and experiments involving free radical scavengers indicated that PFOS degradation was initiated by direct electron transfer on the anode to yield PFOS free radicals, which further reacted with hydroxyl radicals that were generated by water oxidation and adsorbed on the anode surface.
Environmental Science & Technology 53(24):14528-14537(2019)
PFOS degradation by a reactive electrochemical membrane (REM) system utilizing a porous Magneli phase titanium suboxide ceramic membrane that served simultaneously as an anode was tested. The system removed ~98.3% of PFOS under a cross-flow filtration mode at the anodic potential of 3.15 V versus a standard hydrogen electrode. PFOS removal efficiency during the REM operation was higher than that of the batch operation mode under the same anodic potential. A systematic reaction rate analysis in combination with electrochemical characterizations quantitatively elucidated enhanced PFOS removal in REM operation in relation to the increased electroactive surface area and improved interphase mass transfer. PFOS appeared to undergo rapid mineralization to CO2 and F-, with only trace levels of PFCAs (C4-C8) identified as intermediate products. Density functional theory simulations and experiments involving free radical scavengers indicated that PFOS degradation was initiated by direct electron transfer on the anode to yield PFOS free radicals, which further reacted with hydroxyl radicals that were generated by water oxidation and adsorbed on the anode surface.
The Technology Innovation News Survey welcomes your comments and
suggestions, as well as information about errors for correction. Please
contact Michael Adam of the U.S. EPA Office of Superfund Remediation
and Technology Innovation at adam.michael@epa.gov or (703) 603-9915
with any comments, suggestions, or corrections.
Mention of non-EPA documents, presentations, or papers does not constitute a U.S. EPA endorsement of their contents, only an acknowledgment that they exist and may be relevant to the Technology Innovation News Survey audience.
