Comprehensive Strategies for Managing PFAS in Water by Detecting Occurrence and Developing Methods for Analysis and Treatment

Per- and polyfluoroalkyl substances (PFAS) are a class of synthetic fluorinated compounds widely used in industrial and consumer products due to their chemical stability and water-resistant properties but are now recognized as persistent environmental contaminants. However, their persistence in the environment presents significant concerns, as they are not fully removed by conventional water treatment processes, leading to contamination from industrial discharges, wastewater treatment plants, and landfill leachate. The U.S. Environmental Protection Agency (EPA) has cataloged over 15,000 PFAS compounds, including thousands of unidentified fluorinated substances, necessitating the development of advanced analytical methods to detect and quantify PFAS in environmental matrices such as drinking water, surface water, wastewater, and complex samples like firefighting foams. The detection and quantification of PFAS in environmental matrices remain challenging due to the limitations of conventional analytical techniques, which fail to capture the full spectrum of organic fluorine compounds. As a result, total organic fluorine (TOF) measurements have been widely used to detect unspecified fluorinated substances; however, they are susceptible to fluoride background interference, leading to inaccurate organic fluorine quantification. To overcome these challenges, this dissertation introduces a novel solid-phase extraction (SPE) method using activated carbon felt (ACF) and fluorinated cartridges to effectively separate inorganic fluoride from PFAS. This approach enhances the accuracy of PFAS measurement by employing total fluorine detection through PIGE spectroscopy, achieving complete separation of inorganic fluoride and high PFAS recovery, with a detection limit of 1 µg L-1 for PFOS, PFOA, GenX, and PFBS. Limited data exist on the presence and transport of PFAS in surface waters, particularly in regions like Indiana and Michigan. This research fills critical knowledge gaps by evaluating PFAS concentrations and mass fluxes in several watersheds that drain into Lake Michigan, providing insights into contamination sources and pathways. Understanding PFAS distribution in surface waters is essential for informing regulatory policies, mitigating exposure risks, and developing targeted remediation strategies to protect aquatic ecosystems and public health. As PFAS regulations tighten, cost-effective and efficient treatment technologies are urgently needed. Traditional packed-bed adsorbents face mass transfer limitations, reducing their effectiveness in removing PFAS from drinking water. This research demonstrates that porous adsorptive membranes offer a mass transfer-efficient alternative, achieving high adsorption capacities even under dynamic flow conditions. By optimizing electrostatic and hydrophobic interactions, these membranes hold significant potential for scalable water treatment applications, contributing to safer and cleaner drinking water supplies.