Per- and polyfluoroalkyl substances (PFAS) are highly persistent environmental contaminants. Recent non-target analyses indicate that legacy PFAS (e.g., PFCAs and PFSAs) represent only about 20% of total PFAS, while emerging PFAS, including ether-based compounds, dominate across many environmental matrices. Adsorbents such as activated carbon and zeolites are widely applied as in situ amendments to immobilize PFAS in sediments. However, the surfactant-like properties of PFAS drive distinct adsorption behaviors at solid-water interfaces. Conventional macroscopic experiments yield only averaged responses and often cannot resolve the nanoscale mechanisms that govern equilibrium partitioning across the expanding PFAS chemical space. To address these limitations, this study outlines a nanoscale isotherm modeling framework for PFAS in water saturated pore environments. The framework is divided into two representative sorbent classes. Crystalline zeolite models are constructed from crystallographic databases. Aqueous adsorption isotherms are then simulated in RASPA3 using grand canonical Monte Carlo (GCMC) with CB/CFCMC moves to improve sampling in confined, water saturated pores. Activated carbon models can be generated using a liquid carbon quenching strategy with a reactive force field to represent disordered pore networks and heterogeneous surface chemistry. GCMC sampling can be inefficient for bulky PFAS within large activated carbon structures, particularly in densely solvated pore environments. To overcome this, activated carbon isotherms are instead obtained using a concentration-controlled, two-layer aqueous-carbon interface setup with long time equilibration. Overall, this framework provides practical methodological guidance for constructing aqueous-phase PFAS adsorption isotherms and extracting mechanism-driven insights from nanoscale computational simulations.
키워드
PFASActivated carbonZeoliteMonte Carlo simulationMolecular dynamicsSediment remediation