(245d) Uptake and Release of Perfluorinated Surfactants from Macro and Microplastics

Microplastics and perfluorinated (PFAS) surfactants are two of the most notable emerging contaminants reported in the environment. Micron and nanoscale plastics possess a high surface area-to-volume ratio, which increases their potential to adsorb other common environmental pollutants such as PFAS surfactants. The PFAS surfactants are widely considered as ‘forever chemicals’ and a potential threat to human health. However, it is their amphiphilic properties which is often overlooked. This lack of consideration has resulted in a diminished understanding of the environmental mobility of PFAS surfactants, as well as their interactions with environmental media along with the change in their behavior after enduring environmental stresses. Here, we report an intricate relationship between the two anthropogenic pollutants, namely microplastics and PFAS surfactants. Through a series of adsorption-desorption experiments, we delineate the role of the fluoroalkyl tail in PFAS surfactants on their binding affinity to micro and macroplastics. As the number of carbon atoms in the fluoroalkyl chain increases, there is a corresponding increase in the adsorption of PFAS surfactants onto microplastics. This relationship can become modified by environmental weathering, where the PFAS surfactants are released from the macro and microplastic surface after exposure to simulated sunlight. This study identifies a synergistic relationship between PFAS surfactants and plastic pollutants, where they can mutually impact their thermodynamic and transport properties.