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Presentation Slides

This SERDP and ESTCP webinar focuses on DoD-funded research efforts to treat PFAS-impacted groundwater in situ and ex situ. Specifically, investigators will present their work on the efficacy of particulate carbon amendments in arresting downgradient plume migration as well as an evaluation of PFAS removal using regenerable ion exchange resin or activated carbon to inform treatment train design. 

Abstracts

 “Impacts of Particulate Carbon Amendments on Fate of Chemicals of Concern in Groundwater” by Dr. Charles Werth (SERDP Project ER21-1130) 

The goal of this project is to determine the efficacy of particulate carbon amendments (PCAs) in arresting downgradient plume migration and evaluate the operating parameters that maximize PCA performance. While the use of PCAs is increasing for both PFAS and chlorinated volatile organic compounds (CVOCs), questions remain regarding whether PCAs can (1) be delivered to the target zone of choice, (2) negligibly impact permeability and groundwater flow paths, (3) maintain sorption capacity over decades of site management, and (4) ultimately result in lower downgradient PFAS and CVOC concentrations. This presentation will cover efforts to address these questions using results from site data, PCA column-breakthrough profiles, and simple one-dimensional modeling. 

“Evaluation of Granular Activated Carbon and Ion Exchange Resins for Removal of PFAS from Groundwater” by Dr. Erica McKenzie (SERDP Project ER18-1027) 

This project supports SERDP’s efforts to address PFAS contamination in groundwater considering two sorbent media option, anion exchange resins and granular activated carbon (GAC). Activated carbon is a mature technology used to remove a range of contaminants from water, including PFAS. Anion exchange resins have been similarly demonstrated to remove anionic PFAS and have the potential to be engineered for better selectivity and potential regenerability. The objective of this project is to evaluate treatment train options that include PFAS removal onto a sorbent media (ion exchange 

resin or activated carbon), regeneration of the media when suitable, and treatment of the regenerant to degrade the PFAS. The research efforts include bench-scale batch testing (removal and degradation) coupled with a pilot scale demonstration of the treatment train, in addition to ongoing efforts to develop a resin selection/design tool. Knowledge gained from this project will facilitate selection among activated carbon, single use, or regenerable anion exchange resins and inform treatment train design to effectively address contaminated groundwater. 

Speaker Biographies

Dr. Charlie Werth is a professor and the Bettie Margaret Smith Chair in Environmental Health Engineering in the Department of Civil, Architectural and Environmental Engineering at the University of Texas at Austin. His research focuses on fundamentals and impacts of pollutant transport and reaction in porous media, with applications to groundwater remediation, geological carbon sequestration, and catalytic water treatment. He has authored 145 peer-reviewed publications in these areas. Dr. Werth is a Chief Editor of Journal of Contaminant Hydrology, a licensed Professional Engineer in the state of Texas, and a Board-Certified Environmental Engineer (from the American Academy of Environmental Engineers and Scientists). He previously served on the USEPA Science Advisory Board, the Association of Environmental Engineering and Science Professors’ Board, and the DOE’s Environmental Molecular Sciences Laboratory User Committee. Dr. Werth graduated with a bachelor’s degree in mechanical engineering from Texas A&M University, and master’s and doctoral degrees in civil and environmental engineering from Stanford University. 

Dr. Erica McKenzie is an associate professor in the Department of Civil and Environmental Engineering at Temple University and has worked on investigating PFAS since 2013. She is involved with several current SERDP projects investigating PFAS and evaluating PFAS treatment with ion exchange resins, degradation with non-thermal plasma, and uptake into aquatic organisms. She leads a current National Science Foundation-funded project on PFAS interactions with organic matter and the impacts on transport, as well as previous and new projects on PFAS partition from biosolids and approaches to immobilizing PFAS in biosolids. In addition to PFAS, her research group evaluates a range of chemical contaminants, including nutrients, metals, solids, and polycyclic aromatic hydrocarbons, in stormwater runoff, considering a range of media including incoming water, porewater, local groundwater, soils, plants, and potential sorbent amendments. Dr. McKenzie completed her undergraduate degree in environmental engineering at Colorado State University and her doctoral degree in civil and environmental engineering at the University of California, Davis.