Efficient PFAS Removal by Amine-Functionalized Sorbents: Critical Review of the Current Literature

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a group of persistent and mobile fluoro-organic chemicals that have been detected in many water supplies, and their recommended safe concentrations in drinking water are as low as 6 ng/L. Current technological advances suggest that amine-containing sorbents can provide alternative solutions to PFAS control in the treatment of municipal water and wastewater at relatively low PFAS concentrations. The objective of this review is to provide critical analysis of the development and application of amine-containing sorbents for PFAS removal. The removal of PFAS by aminated sorbents relies on the combined effects of three main factors: (i) electrostatic interactions with functional groups of the sorbent, (ii) hydrophobic interactions with the sorbent and between PFAS molecules, and (iii) sorbent morphology. The design of next-generation sorbents should take into consideration these three factors and their relative contribution. We also provide an outlook and highlight of the key areas of innovative research needs to develop more efficient sorbents that will enable compliance with the increasingly stringent regulations of PFAS.