Characterizing PFAS Retention and Transport in Soil

Abstract:

There is great current interest in the retention and transport behavior of per- and polyfluoroalkyl substances (PFAS) in the subsurface. It has been demonstrated that soils are a primary reservoir for PFAS, and serve as potential long-term sources of groundwater contamination. Understanding the transport behavior of PFAS in soil and the vadose zone is critical for accurate site characterizations and risk assessments and for the design of effective mitigation efforts. Adsorption at air-water interfaces is a critical retention process for PFAS transport in unsaturated porous media. Characterization and simulation of PFAS transport in soil requires robust parameterization of multiple key variables, including the air-water interfacial adsorption coefficient (Kia) and air-water interfacial area (Aia). Methods for measuring and estimating these key variables are discussed.