(546g) Effect of Salt on per- and Polyfluoroalkyl Substances (PFAS) Air-Water Interfacial Properties

Per- and polyfluoroalkyl substances (PFAS) are a group of partially or fully fluorinated organic compounds. The PFAS have been widely used in various applications, i.e., aqueous film-forming foams (AFFFs), coating materials, and surfactants, due to their excellent physicochemical properties. However, PFAS can be accumulative in organisms and the environment, and are associated with the human health concerns. Water resources have been contaminated by PFAS due to their surfactancy and tendency of being transported through the air-water interfaces. Foam fractionation is one of the promising remediations to remove surfactants and colloids from water resources; however, it is currently not viable for removing PFAS. The key for improving the effectiveness of foam fractionation for PFAS removal is PFAS interfacial properties, such as the dynamic surface tension and dilatational rheological properties. Therefore, in the present work, the dynamic surface tension and dilatational rheology of long-chain and short-chain PFAS are studied. The adsorption of PFAS at the air-water interface are analyzed according to the surface tension results. Furthermore, the mechanical strength of PFAS-adsorbed air-water interface is examined based on the interfacial rheology. Additionally, the effect of electrolytes on PFAS air-water interfacial properties is investigated.