Treatment Trends and Hybrid Methods for the Removal of Poly- and Perfluoroalkyl Substances from Water—A Review

Poly- and perfluoroalkyl substances (PFASs) encompass a diverse group of engineered chemicals extensively manufactured and utilized in various facets of human life. They exhibit widespread distribution in aquatic environments due to their prevalent usage and resistance to degradation. Recognized for their toxicity to both humans and animals and a major public health concern, various techniques have been employed to eliminate them from water sources. However, these methods have shown limitations in efficiently and cost-effectively removing PFASs, particularly in the presence of other water contaminants, which are often present at much higher concentrations than PFASs. This review critically discusses these methods, presenting their respective advantages and limitations. This review illustrates that, rather than solely depending on individual methods as often presented in previous reviews, a combination of techniques has shown greater effectiveness in PFAS removal, owing to their synergistic effects. Hybrid methods capable of practical integration for efficient PFAS removal include adsorption coupled with oxidation, membrane separation combined with oxidation, and the integration of adsorption with membrane separation and incineration. In these hybrid approaches, one technique extracts PFASs from contaminated water and concentrates them, while the other degrades the extracted PFASs. The review presents strategies to enhance the performance of these hybrid methods.