CAS: Fluorine Beyond PFAS: Pathways to Sustainable Fluorochemical Design Through Environmental Degradation Studies and Fluorine Mass Balances

With support from the Environmental Chemical Sciences Program in the Division of Chemistry, William Arnold, William Pomerantz, and Sebastian Behrens at the University of Minnesota-Twin Cities will investigate the environmental presence and degradation of mass-produced chemicals, specifically pharmaceuticals and pesticides that contain one or more fluorine atoms. While the poly- and perfluoroalkyl substances (PFAS) class of chemicals has received much attention, there is limited understanding about the identity and fate of other fluorinated chemicals that reach the environment and whether unknown, persistent byproducts are formed. This project will expose multiple students to green chemical design principles and offer interdisciplinary training in fundamental environmental, synthetic, and computational chemistry as well as the biological processes and engineering concepts involved in water treatment. Partnerships with government, utility, and industry/consulting partners will provide a means to communicate with those actively seeking to assess and regulate fluorinated contaminants. Forums for communities impacted by chemical pollution facilitated by a community artist will be used to share perspectives and concerns regarding potential solutions to pollution issues. A major impetus for this work is the incorporation of fluorine into increasingly more organic chemicals, even as the most widespread and environmentally persistent fluorinated actors (i.e., PFAS) are phased out. Given that there are few natural fluorinated organic molecules, it is critically important to understand how the incorporation of fluorine into organic molecules affects the full suite of potential degradation pathways in natural and engineered aquatic environments and, in particular, what persistent fluorinated products form from both chemically- and biologically-driven processes. The project will use a screening approach to identify fluorinated functional groups resistant to transformation. The reaction rates for abiotic and biological degradation processes will be measured and fluorinated reaction products identified. Lastly, a method using fluorine nuclear magnetic resonance spectroscopy will be developed to quantify fluorinated compounds in environmental samples. Ultimately, this information will guide the development of molecules that require fluorine incorporation to obtain a desired effect, yet are able to breakdown into innocuous products under environmental conditions. 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.