Zekun Liu
PhD candidate
University of California, Riverside
Zekun Liu is the 4th year PhD candidate in Chemical and Environmental Engineering Department from University of California, Riverside. His research mainly focused on PFAS structural-reactivities studies in UV-based reduction technologies (e.g., UV/Sulfite, UV/Sulfite+iodide). He has demonstrated near-complete defluorination with integrated reduction and oxidation process (Environ. Sci. Technol. 2021, as the first author) and substantially accelerated defluorination with UV/Sulfite+iodide process (Environ. Sci. Technol. 2022, as the first author).
PRESENTATION TITLE
Accelerated degradation of perfluorosulfonates and perfluorocarboxylates by UV/sulfite + iodide: Reaction mechanisms and system efficiencies
The addition of iodide (I−) in the UV/sulfite system (UV/S) significantly accelerated reductive degradation of perfluorosulfonates (PFSAs, CnF2n+1SO3−) and perfluorocarboxylates (PFCAs, CnF2n+1COO−). The results showed that the degradation rates of PFCAs and PFSAs were improved by 3~10 times in UV/S+I. The enhanced reaction rates also efficiently saved the energy consumption. The addition of iodide substantially enhanced sulfite utilization in treating concentrated PFAS. For example, we prepared a synthetic brine mimicking concentrated PFAS mixtures from ion-exchange resin regeneration (e.g., ~300 mg/L PFAS), the UV/S+I system achieved >99.7% PFAS removal and >90% overall defluorination.