The widespread use and disposal of per- and polyfluoroalkyl substances (PFASs) has impacted groundwater and surface water resources globally.  There is a critical need to develop effective biological as well as abiotic technologies for the degradation of this class of contaminants in the environment. Physical-chemical treatment strategies may be needed for rapid transformation of recalcitrant chemicals, while biological treatment strategies, being less cost- and energy-intensive, may be more suited for the slow treatment of large volumes of water at impacted sites. This presentation will summarize various biological, electrochemical, and sonolytical technologies (BEST) individually and in treatment trains for PFAS destruction.  Ligninolytic fungi transformed fluorotelomer alcohols towards more degradable polyfluorocarboxylates with lower yields of perfluorocarboxylates.  Certain components of Aqueous Film Forming Foams (AFFF) were aerobically transformed by the fungus <i>Trametes versicolor</i> as well as by its laccase enzymes.  Biotransformation generally reduced the energy consumption, material usage, and treatment costs of subsequent electrochemical oxidation.  Among the tested mesh anodes, Magnéli-phase titanium suboxides were most effective in flow-through PFAS mineralization processes.  Over 99% of PFAS removal was achieved, demonstrating fluoride generation without the accumulation of aqueous organofluorine intermediates.  For sonolysis at 700 kHz, the pyrolysis of PFAS mixtures resulted in the mineralization of most non-fluorinated, polyfluorinated, and some perfluorinated constituents of AFFF.  PFASs followed first-order removal kinetics increasing with chain length. For the same chain length, carboxylates had higher removal rates as compared to sulfonates.  In a treatment train, in which the AFFF was first treated with laccase followed by ultrasonic treatment, over 90% of perfluorooctane sulfonate (PFOS) was removed along with nearly complete degradation of polyfluorinated precursors. In conclusion, our results imply that abiotic—biotransformation treatment trains can be customized to lower the overall time and energy requirements for the removal of PFASs from impacted environmental media.

What are B.E.S.T technologies for the destruction of per- and polyfluoroalkyl substances?

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.