Comparison of currently available PFAS remediation technologies in water: A review

Remediation of Poly- and perfluoroalkyl substances (PFASs) in the environment has rapidly increased due to growing concerns of environmental contamination and associated adverse toxicological effects on wildlife and humans due to bioaccumulation and extreme persistence. Although, PFASs are highly recalcitrant to conventional water treatment processes, there are some effective techniques available. Those techniques involve exceedingly high costs due to high energy use, and high capital or operational costs. Thus, most remediation techniques have limitations in field applications even though the laboratory scale experiments are promising. As a result of stringent new health and environmental regulatory standards are being established, development of suitable water treatment methodology is more challenging. Most of the separation and destruction techniques have their own limitations in field applications while the biological approaches to treat PFASs are extremely limited and are not currently considered as viable. In this review, extra consideration is given to novel advanced techniques for wide array of PFAS classes including short chain PFAS removal, and compare their efficiencies, effectiveness, energy use, sustainability, cost, and simplicity in laboratory scale to field applications. Electrochemical, sonochemical, advanced oxidation processers (AOPs) and plasma together with novel hybrid techniques are considered as effective approaches for PFASs removal and have shown promising results for long chain and some short chain PFASs, as well as extremely persistent per-fluoro alkyl acids (PFAAs). Therefore, it is essential to better understand the removal mechanisms to optimise the advanced treatment processes like hybrid techniques because, the unique physicochemical characteristics of various PFASs impose difficult challenges. Careful selection of a combined effective treatment methodology in an integrated processing unit, would be a revolutionary approach for complete elimination of PFASs from the environment. Considering the site-specific water quality parameters together with community perspectives will also make it more viable in real world field applications.