Presentation Profile
Hidden on Plastic: Do Microplastics Alter the Environmental Fate and Measurement of PFAS? A Molecular-Descriptor Assessment
Main Author
Jagos Radovic - University of Houston - Center for Petroleum Geochemistry (UH-CPG)
Abstract:
Per- and polyfluoroalkyl substances (PFAS) and microplastics are two classes of emerging contaminants in aquatic systems, yet they are almost always studied separately. Because many PFAS are surface-active and many microplastics present hydrophobic, chemically heterogeneous surfaces, PFAS may sorb to microplastic particles, potentially shifting their environmental distribution and biasing standard analytical methods that measure only filtered water. The magnitude of these effects, and the conditions under which they matter, remain poorly quantified. We combine interpretable molecular descriptors with a mass-balance framework to identify when microplastic-associated PFAS becomes environmentally and analytically relevant. Descriptors computed for an 11-compound PFAS panel (C4–C10 carboxylates and sulfonates and a perfluoroether acid) reproduce reference molecular weights and resolve headgroups by polar surface area, establishing a basis for predicting PFAS–microplastic affinity. Preliminary results of mass-balance analysis across a broad range of sorption strengths and particle loadings indicate that the particle-bound PFAS fraction is strongly loading-dependent: minimal under ambient freshwater conditions, but potentially substantial in high-solids matrices such as wastewater, stormwater, and turbid samples, where filtrate-only methods would under-recover total PFAS by a comparable margin. These results identify the specific loading and sorption regimes in which microplastics can alter the operationally defined dissolved–particulate distribution of PFAS, and frame testable hypotheses for targeted laboratory validation.
