Collaborative Research: ERASE-PFAS: A "concentrate-and-destroy" technology for treating per- and polyfluoroalkyl substances using a new class of adsorptive photocatalysts

Per- and polyfluoroalkyl substances (PFAS) have been manufactured and widely used in hundreds of consumer products and industrial processes for decades. Release of PFAS into the environment has resulted in drinking water supplies for millions of U.S. residents to become contaminated at levels exceeding United States Environmental Protection Agency health advisory limits. Unfortunately, conventional water treatment processes are not effective at removing or destroying PFAS due to the unique molecular properties of these compounds. This has created an urgent national need for water treatment technology to address this problem. The goal of this research is to address this problem through a multi-phase research project focused on developing “trap and destroy” technology. This technology utilizes a new class of adsorptive materials to efficiently capture PFASs from water, followed by degradation using targeted ultraviolet and sunlight-assisted reaction. Successful completion of this research will benefit society through the production of effective PFAS treatment technology. Additional benefits result from increased scientific literacy through enhanced public awareness of PFAS contamination, as well as by increasing the diversity of the Nation’s STEM workforce by engagement of K-12, undergraduate, and graduate students from underrepresented groups in research and training. The overarching research goal of this project is to develop and fully characterize an innovative technology to cost-effectively remove and degrade PFAS from contaminated water. The technology is based on a new class of adsorptive photocatalysts that can selectively adsorb PFAS from water to the photoactive solid surface, and then destroy PFAS in situ under UV or solar light. This project will target both legacy PFAS and their newer substitutes such as GenX. The research goals will be accomplished through a series of interconnected research tasks to: i) develop adsorptive photocatalysts optimized for treatment of a wide range of PFAS, ii) characterize the speed, selectivity, and capacity of the adsorptive photocatalysts for PFAS treatment, iii) characterize UV- and solar-light solid-phase photocatalysis of the pre-adsorbed PFAS, and iv) explore ways to enhance photocatalysis through amendment with low-cost oxidants and manipulation of reaction conditions. The underlying reaction mechanisms will be investigated through all stages of the research using state-of-the-science microscopic and spectroscopic analyses of the materials, high-resolution spectroscopic analysis of the reaction products, and modern density functional theory calculations. A preliminary cost analysis will be carried out to assess the cost-effectiveness of the technology compared to alternative treatment options. Successful completion of the project will potentially lead to an innovative technology that can cost-effectively treat low concentrations of PFAS in large volumes of contaminated water. More broadly, the knowledge gained from this project will also advance our understanding of the synergistic effects of nanoscale hybrid phases and multiple redox cycles on the overall performance of reactive composite materials, and potentially transform our knowledge on fabrication and application of carbon-modified, multi-phase photocatalysts. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.