Abstracts

“Development of Novel Functionalized Polymeric Thin Films for Equilibrium Passive Sampling of PFAS in Surface and Groundwater” by Dr. Upal Ghosh (ER20-1336)

Accurate assessment of PFAS exposure and risk at DoD sites requires time-integrated measurements in water at sub-parts per trillion concentrations. We are exploring the concept of equilibrium passive sampling for PFAS that should predict the concentration of PFAS in water based on equilibrium partitioning into the sampler without the need for site-specific calibration. Our goals are to identify sampler materials with the potential to mimic PFAS partitioning into animals and sediments and provide reversible sorption in a timeframe appropriate for in situ samplers. We tested a range of candidate materials, including three broad classes of polymer films embedded with suitable sorbents for PFAS. The most promising were activated carbon and silica-bonded human serum albumin embedded in agarose, two sorbent resins embedded in cellulose acetate, and PDMS, which yielded log sampler water partition coefficients close to 3 for many PFAS. Sampler equilibration time in sediments was approximately one week and was reversible. Investigation of the isotherms suggested that the sorption can be described across the ng/L range commonly found in natural waters to the µg/L found in contaminated sites. Ongoing work is testing the sampler for a larger range of PFAS in more complex water matrices.

“Demonstration of a High-Resolution Passive Profiler (HRPP) for Characterizing the Distribution of PFAS in Groundwater” by Dr. Andrew Jackson (ER21-5104)

This project demonstrates the application of a high-resolution passive profiler (HRPP) to quantify per- and polyfluoroalkyl substances (PFAS) in groundwater aquifers and at groundwater-surface water interfaces. The HRPP can produce high resolution vertical profiles (<20 cm) of PFAS concentration and flux as well as groundwater velocity and geochemical conditions. This project is demonstrating the utility of the device for three types of occurrences including source areas, along plume transects, and groundwaters discharging to surface water. Using these scenarios, the project team is demonstrating the ability of the tool to evaluate the impact of the air/water interface, potential for storage and release from source zones in heterogenous horizontal layered geologic formations, and identifying discharge points of PFAS surfacing from groundwater to surface water. The HRPP tool is expected to provide high-resolution data on the distribution and flux of relevant PFAS, which will improve site assessments, allow more robust site-specific transport models and risk-based evaluations, as well as improved development and assessment of remedial approaches. This presentation will highlight the findings from two large field deployments in which the HRPP performance is compared to traditional monitoring methods.

Speaker Biographies

Dr. Upal Ghosh is a professor in the Department of Chemical, Biochemical, and Environmental Engineering at the University of Maryland Baltimore County where his group performs research on the fate, effects, and remediation of toxic pollutants in the environment. His research has contributed to the development of monitoring tools for pollutant bioavailability, especially work on passive sampling. Dr. Ghosh has also led the development and transition of novel sediment remediation technologies. His work has been published in the leading journals in the field and his technology development efforts have led to several U.S. patents. His research contributions have been recognized with multiple awards including the University System of Maryland Regents award for Excellence in Scholarship, Research, and Creative Activity in 2016. Dr. Ghosh is a co-founder of two startup companies, Sediment Solutions LLC (manufacturer of SediMiteTM) and RemBac Environmental to transition novel sediment remediation technologies to the field. He has an undergraduate degree in Chemical Engineering from the Indian Institute of Technology, and master’s and doctoral degrees in environmental engineering from the State University of New York at Buffalo.

Dr. Andrew Jackson is a professor and the chair of the Department of Civil Environmental and Construction Engineering at Texas Tech University in Lubbock, Texas. His research interests include evaluating the fate and transport of a variety of contaminants in natural environments such as perchlorate, heavy metals, explosives, PFAS, and chlorinated solvents, along with the development of methods to study these processes at appropriate scales. His work focuses on understanding how biogeochemistry controls the fate of contaminants. Dr. Jackson has served as a principal or co-principal investigator on grants sponsored by a variety of agencies including SERDP, ESTCP, DOE, EPA, and NASA. He is the recipient of several awards including Environmental Science and Technology’s best paper of the year, SERDP Project of the Year, the ICES award, Barnie Rushing Distinguished Research Award, and the President’s Excellence in Teaching Award. He has published over 120 journal publications and book chapters with more than 5,000 citations. Dr. Jackson received a bachelor’s degree from Rhodes College, and master’s and doctoral degrees from Louisiana State University.