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Understanding and Quantifying the Retention and Migration of Per- and Polyfluoroalkyl Substances in the Vadose Zone

Sponsored by National Science Foundation

$398.5K Funding
2 People

Related Topics


Per- and polyfluoroalkyl substances (PFAS) are manmade chemicals that have recently been found in soils and waters all over the U.S. and other countries. Their widespread use and and persistence in the environment may result in exposure of millions of people in the U.S. to PFAS-contaminated drinking water. Because of the impacts of PFAS to human health, it is important to understand how these contaminants move in the environment and reach points of exposure. To date, the movement of PFAS through soil to groundwater is poorly understood and difficult to predict. Knowing how they move and how long they stay in soils is critical for cleanup and reducing exposure. The proposed project will integrate experimental and modeling approaches to study the factors that control the movement of PFAS in soils and groundwater. The project will generate data and predictive tools that can provide valuable information for stakeholders and decision makers. The project will further benefit society by supporting STEM education, including broadening of participation of underrepresented groups, and informing the broader community about the risks posed by PFAS-contaminated water and potential for intervention to mitigate risks. A growing body of field data demonstrates that soils serve as significant sources of PFAS to groundwater. However, the primary mechanisms that control the long-term retention of PFAS in soils remain poorly understood. This project will address this critical knowledge gap by combining novel experimental and mathematical modeling approaches. Specifically, the project will 1) conduct investigations of PFAS transport in unsaturated porous media under transient flow conditions; 2) develop and use state-of-the-art mathematical models that represent surfactant-induced flow and PFAS-specific transport processes to identify the critical factors that control the retention of PFAS in soils and the long-term mass discharge to groundwater. The conceptual and computational tools developed in this project are expected to contribute to the establishment of science-based state and federal regulations for PFAS in the soils and to develop protocols on remediation. The research findings will be disseminated to a local water utility to improve water resources management and remediation decisions for PFAS contamination problems in Tucson, Arizona. In addition, the project will train underserved undergraduates in STEM at the University of Arizona through the Arizona Science, Engineering and Math Scholars Program and educate the local community about PFAS contamination through by collaboration with the Flandrau Science Center & Planetarium. 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.