Leah Stewart, “Adsorptive Removal Methods of PFAS from Water and Wastewater”
Mentors: Yin Wang & Qianqian Dong, Civil & Environmental Engineering
Per- and Polyfluoroalkyl substances and surfactants (PFAS) are a group of synthetic chemicals which have been widely used in commercial and industrial products since the 1940s. PFAS are extremely persistent in the natural environment and some have been shown to accumulate in human and animal tissues and are potentially toxic to humans, making them an emerging contaminant of concern. The Environmental Protection Agency (EPA) is currently studying these compounds to set an enforceable drinking water standard. Additionally, the National Defense Authorization Act (NDAA), which added PFAS to the Toxics Release Inventory (TRI), became effective December 20, 2019 and requires certain industries to track their PFAS usage. Because of this new and anticipated regulation, low-cost and effective PFAS remediation methods are needed. Removal of PFAS represents a special challenge for water/wastewater treatment because of their unique chemical/physical properties that include high water solubility, the high stability of C-F bonds, and varied chemical structures. In this study, we prepared a suite of mineral-based adsorbents via modification of representative naturally occurring clays with various organic functionalities. The performance of the adsorbents was examined for the removal of both short- and long-chained perfluorocarboxylic and perfluorosulfonic acids (PFCAs/PFSAs). Preliminary research shows promising capacity for some high-performance media, indicating potential scalability for remediation efforts in natural waters.