Sequestration of per- and polyfluoroalkyl substances (PFAS) by adsorption: Surfactant and surface aspects

Per- and polyfluoro alkyl substances (PFAS) are synthetic compounds composed of a fully or partially fluorinated carbon chain. Fluorinated surfactants are a major PFAS subgroup. Their widespread use has resulted in their release into the environment and accumulation in water. The sequestration of PFAS from aqueous solution by adsorption is a pressing and challenging environmental pollution problem which necessitates surface and colloid science to offer solutions for the benefit of a sustainable future. In this review, we first provide an overview of the aqueous solution and self-assembly properties of common PFAS surfactants. Next, we discuss physical adsorption of PFAS surfactants, which is the first step used to concentrate PFAS prior to their subsequent proper disposal or destruction, with a focus on “natural” materials such as activated carbon and biopolymers, and on surfactant/surface/colloid aspects. In closing, we offer some perspective on gaps in fundamental knowledge and future research directions.