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This SERDP and ESTCP webinar focuses on DoD-funded research efforts to improve screening and treatment approaches for PFAS. Specifically, investigators will discuss the development and field-deployment of a rapid field-screening test for PFAS that greatly reduces the time and costs associated with site characterization and monitoring efforts at PFAS-impacted sited. In addition, investigators will talk about the development of a reductive PFAS transformation technology that employs nickel and zero-valent iron-activated carbon nanocomposites.

“Developing PIGE into a Rapid Field-Screening Test for PFAS” by Dr. Graham Peaslee (SERDP Project ER19-1142)

This project was designed to optimize the operating parameters needed to take a laboratory technique called Particle Induced Gamma-ray Emission Spectroscopy (PIGE) and turn it into a field-deployable approach to rapidly screen for the presence of per- and polyfluoroalkyl substances (PFAS) in groundwaters at sites impacted by aqueous film-forming foams (AFFF). This method of screening for the presence of organic fluorine as a surrogate for PFAS in groundwater could potentially save significant time and money in characterizing occurrence and/or monitoring removal or destruction. As part of this SERDP effort, we have optimized the sample preparation and PIGE technique and modified the design of a field-deployable accelerator system previously developed by the Defense Advanced Research Projects Agency (DARPA) so that this technique could be used in situ to make rapid measurements of total fluorine. A prototype system would be capable of making rapid PIGE measurements (minutes per sample) at a field site. As discussed during this presentation, the discovery of an inline filter material that allows rapid sample preparation (minutes per sample) for PIGE measurement detection limits in the 10-50 part per trillion range for allanionic PFAS simultaneously would make this system capable of being used in a variety of situations to facilitate site characterization, remediation and long-term monitoring. This could reduce the time site characterization and remediation efforts significantly.

“PFAS  Transformation and Mitigation with nNiFe -Activated Carbon Nanocomposites” by Dr. Linda Lee (SERDP Project ER-2426)

Destructive technologies that target PFAS are often limited by not addressing all PFAS, being energy intensive, or not being amenable for in situ application. Oxidative processes involving hydroxyl and sulfate radicals have been successful for carboxylates, but they are unsuccessful in treating sulfonates such as perfluorooctanesulfonic acid (PFOS). While some reductive techniques like ultraviolet light (UV)-activated sulfite can transform PFOS, they are not amenable for in situ use. As part of this SERDP-funded project, we developed a reductive transformation technology that employs nanocomposites prepared by synthesizing Ni (2 wt%)/Fe  nanoparticles onto combined powdered-granulated activated carbon (AC) material with a high surface area (1000 m²/g) under an oxygen-free environment, followed by reacting the nanocomposites with PFAS-impacted waters under heated conditions (50 to 60 degrees Celsius [°C]). During this webinar, a summary of nNiFe -AC reductive transformation studies at 50 and 60 °C conducted in batch and column reactors will be presented for several PFAS including several perfluoroalkyl carboxylates (PFCAs), three perfluoroalkyl sulfonates (PFSAs), two fluorotelomer sulfonates (6:2 and 8:2 FTS), and GenX in single and mixed solute systems along with some mechanistic insights. A patent is pending, and we are working with companies that have expressed interest in moving this technology forward. Further optimization is underway to advance this technology given its potential to be a customizable, controlled release, and injectable solution that is amenable for inclusion in both in situ and ex situ treatment train approaches.

Dr. Graham Peaslee is a professor of physics at the University of Notre Dame in South Bend, Indiana. Dr. Peaslee leads an active research group in the area of applied nuclear science, where he brings established nuclear measurement techniques to pressing environmental issues. One particular area of recent research has been the application of PIGE spectroscopy to measuring total fluorine in environmental samples and consumer products. Dr. Peaslee currently serves as the principal investigator on several grants using PIGE and other Ion Beam Analysis techniques to study the environmental fate and transport of chemicals of concern. He has over 210 peer-reviewed publications. He earned his bachelor’s degree in chemistry from Princeton University and his doctoral degree in chemical physics from the State University of New York.

Dr. Linda Lee is a full professor in the agronomy department at Purdue University. Her research program focuses on understanding the processes that govern the environmental fate and remediation of contaminants in various media for use in contamination mitigation, decision tools, and management guidelines for both industrial and agricultural settings. Dr. Lee currently has funded projects with the Environmental Protection Agency, the Department of Defense, the National Institutes of Health, the National Academy of Sciences, and the Water Research Foundation. For the past 15 years, her research has had an increasing focus on the environmental behavior, occurrence and remediation of PFAS. She has over 110 peer-reviewed journal publications, 25% of which  are PFAS-focused. Dr. Lee has served on multiple national and international advisory groups and as an expert reviewer addressing water quality issues, sustainable land-applied biosolid policies, chemical risk prediction and management, and consumer product regulations.She earned her bachelor’s degree in chemistry, her master’s degree in environmental engineering, and her doctoral degree in soil chemistry and contaminant hydrology, all from the University of Florida.