Abstract
Fluorinated surfactants, which fall under the class of per- and polyfluoroalkyl substances (PFAS), are amphiphilic molecules that comprise hydrophobic fluorocarbon chains and hydrophilic head-groups. Fluorinated surfactants have been utilized in many applications, e.g., fire-fighting foams, paints, household/kitchenware items, product packaging, and fabrics. These compounds then made their way into the environment, and have been detected in soil, fresh water, and seawater. From there, they can enter human bodies. Fluorinated surfactants are persistent in water and soil environments, and their adsorption onto mineral surfaces contributes to this persistence. This review examines how fluorinated surfactants adsorb onto mineral surfaces, by analyzing the thermodynamics and kinetics of adsorption, and the underlying mechanisms. Adsorption of fluorinated surfactants onto mineral surfaces can be explained by electrostatic interactions, hydrophobic interactions, hydrogen bonding, and ligand and ion exchange. The aqueous pH, varying salt or humic acid concentrations, and the surfactant chemistry can influence the adsorption of fluorinated surfactants onto mineral surfaces. Further research is needed on fluorinated surfactant adsorbent materials to treat drinking water, and on strategies that can modulate the fate of these compounds in specific environmental locations.
Highlights
Water, a necessity for all life on this planet, is regularly tested for its quality; past actions have made this task challenging
The research highlighted above by Jian et al [87], Qian et al [93], and Xiao et al [42] contributes toward an improved understanding pertaining to polyfluoroalkyl substances (PFAS) adsorption onto mineral surfaces: The sign of enthalpy can explain whether an adsorption process is exothermic or endothermic and if it is promoted by temperature increase; and the value of entropy indicated the role of disorder within the adsorption process
The adsorption of PFAS onto mineral surfaces is a topic of interest, since PFAS have an affinity for mineral surfaces commonly found in nature
Summary
A necessity for all life on this planet, is regularly tested for its quality; past actions (or lack of action) have made this task challenging. Several studies have examined the adsorption of fluorinated surfactants onto rather ill-defined “fresh water sediments, marine sediments, and soils” [4,65,66,67,68,69,70,71,72,73,74,75,76,77] Whereas these articles often report on the physical characteristics and locations from where these surfaces have been found, the chemical composition and surface properties have not been sufficiently defined to be included in Table 2 and discussed in detail in this review. This review aims to further expand the understanding of fluorinated surfactant adsorption onto mineral surfaces in an aqueous environment, so that the fate and transport of PFAS is better understood With this being known, absorbent materials and processes can be more effectively and efficiently developed and deployed, in order to remove various PFAS from known locations and mineral surfaces, so that ecosystems can be rendered safer for all
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
