The presence of per- and polyfluoroalkyl substances (PFASs) in water supplies is a threat to environmental and human health. Standard water purification methods are generally ineffective for PFAS removal. This research will explore a potentially transformative approach to engineering environmentally compatible adsorbents for PFAS removal, and the research activities will directly advance discovery and fundamental understanding of materials that selectively remove PFASs from drinking water sources. This research collaboration between Florida International University and North Carolina State University will promote teaching, training, and learning by bringing together a research team composed of undergraduate students, graduate students, a postdoctoral research associate, and researchers from two institutions in different states. This project will provide a valuable environment for underrepresented students through multidisciplinary research experiences, participation in scientific workshops, professional development, and engagement in outreach activities. Project results will be broadly disseminated through peer-reviewed publications, presentations at scientific meetings, and special presentations and seminars. Additional a web seminar series is planned to enhance the public awareness of the health risks of PFASs and educate water suppliers on effective methodologies for PFAS removal to protect human health and help secure the Nation's water supply. The overall objective of the research is to explore the combination of environmentally friendly amino beta-cyclodextrins (am-beta-CDs) and graphene oxide-based materials for the remediation of legacy and emerging PFASs. Graphene oxide will be linked to functionalized cyclodextrins (CDs) for the remediation of legacy PFASs and emerging perfluoroalkylether acids, such as GenX, and short-chain PFASs. Preliminary results show that beta-cyclodextrin (beta-CD) readily encapsulates a variety of PFASs with association constants up to 10^5 M^-1, resulting in complexation of up to 95% of PFAS in solution. While the team has demonstrated enhanced removal of perfluoro octanoic acid (PFOA) using beta-CD in combination with activated carbon, there is a lack in the fundamental understanding about the CD complexation of PFASs and how the CD:PFAS complex properties may be exploited for remediation. This knowledge gap prevents the optimization of these systems for PFAS monitoring and water treatment. This research will test the hypothesis that am-beta-CD:PFAS complexes will persist in environmentally relevant conditions such that am-beta-CD-based graphene oxide adsorbents can be utilized for PFAS remediation. Guided by strong preliminary evidence and the extensive experience of the assembled researchers, the group will pursue two specific objectives: (1) Determination of binding constants for and detailed characterization of am-beta-CD:PFAS complexes; and (2) employ am-beta-CD-attached graphene-oxide matrices for remediation of PFASs. Removal of short-chain and emerging PFASs will be the highest priority. The study will contribute to the fundamental understanding of the molecular interactions of PFASs and CDs and the utility of CD-based two-dimensional nano-adsorbents. The project is expected to provide information critical for the development of sustainable strategies for PFAS remediation.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.
