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).
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.