Prof. Timothy James Strathmann
Colorado School of Mines, United States, Colorado
Abstract: The ultimate goal for treatment of per- and polyfluoroalkyl substances (PFASs) is to both remove and destroy the chemicals. Achieving the goal of removal remains poorly defined, but most experts agree that it will require meeting stringent standards (e.g., low ng/L concentration) for not only commonly mentioned PFASs like PFOS and PFOA, but the class of chemicals as a whole. Removal can be achieved by a variety of adsorption and membrane separations technologies, with granular activated carbon (GAC) adsorption and anion exchange resins (AER) being the only technologies currently adopted at full scale. A range of other adsorbents, membrane processes, and innovative foam fractionation processes are also being studied. Each process has distinct advantages and disadvantages, achieves varying levels of PFAS concentration, and concentrates PFAS to varying degrees within residual byproduct streams. Researchers have also been investigating the effectiveness of different destructive treatment technologies for PFAS-contaminated water. This is challenging due to the recalcitrant nature of PFASs. To date, the most effective approaches include thermochemical, electrocatalytic, and photochemical and plasma-based technologies. Published reports indicate varying levels of success, but collectively results show energy requirements that exceed the most costly water treatment processes (e.g., seawater desalination). As a result, none have been adopted as a primary treatment technology at full scale. A more promising strategy involves coupling separations processes (to achieve treatment goals while simultaneously concentrating the PFAS contaminants into smaller volumes) with destructive treatment of the resulting byproduct streams. This presentation will summarize the state of the science and compare alternatives for both (1) separation/concentration of PFASs, and (2) destructive treatment of PFAS-contaminated concentrate streams, using work from recent laboratory and pilot studies as examples. Research needs and opportunities will also be discussed.
Host：Prof. Cheng Gu
Executive Editor
Nanjing University
Time：09:00am May 20, 2022 (Beijing time)
Zoom ID: 816 9975 7155
Password: 551621
Bilibili: 25002335
