IMPACT OF CHANGING ENVIRONMENTAL CONDITIONS ON DESORPTION OF PFAS FROM SEDIMENTS IN LACUSTRINE ENVIRONMENTS

Per- and poly-fluoroalkyl substances (PFAS) are persistent environmental contaminants characterized by their chemical stability, bio-accumulative effects, and ability to absorb onto particle surfaces, allowing a reservoir of historic PFAS species to build in accreting sediments. Seasonal stratification driven by the warming of surface waters and inflow stagnation in lakes exposes sediments to alkaline and hypoxic water conditions. The effect of these conditions on the desorption of PFAS from sediment particles is of interest, as desorption into the water column would be a potential compounding contamination source in drinking water. North Carolina has multiple significant PFAS sources contributing to contamination in primary drinking water systems. Jordan Lake has a dam-controlled inflow and receives 80% of its consistent sediment accumulation from the highly industrially contaminated Haw River, allowing it to act as a PFAS deposit. A well-characterized sediment core from Jordan Lake with known PFAS concentrations was processed and exposed to a range of alkaline and hypoxic conditions to mimic those experienced by turbid bottom sediments during seasonal stratification. The concentration of contaminants in the water column after exposure was quantified and compared to the known PFAS concentration in respective sediment layers to determine the potential for desorption in the sediment. The findings of this study are significant in understanding the contribution of PFAS desorption to drinking water contamination and the potential effects of larger-scale sediment disturbance.

Presentation Preference: Poster

Primary Presenter: Lauren McShea, University of North Carolina at Chapel Hill (lmcshea@unc.edu)

Authors:

Lauren McShea, University of North Carolina at Chapel Hill  (lmcshea@unc.edu)

Sherif Ghobrial, University of North Carolina at Chapel Hill  (reef@unc.edu)

Brent McKee, University of North Carolina at Chapel Hill  (bamckee@email.unc.edu)

Nadia Shepard, North Carolina State University  (nsheppa@ncsu.edu)

Detlef Knappe, North Carolina State University  (knappe@ncsu.edu)