A review of the occurrence, transformation, and removal of poly- and perfluoroalkyl substances (PFAS) in wastewater treatment plants

A review of the occurrence, transformation, and removal of poly- and perfluoroalkyl substances (PFAS) in wastewater treatment plants

Publication Year:
Lenka, Swadhina Priyadarshini; Kah, Melanie; Padhye, Lokesh P.
Resource Type:
Journal Article
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Resource Information


Poly- and perfluoroalkyl substances (PFAS) comprise more than 4,000 anthropogenically manufactured compounds with widescale consumer and industrial applications. This critical review compiles the latest information on the worldwide distribution of PFAS and evaluates their fate in wastewater treatment plants (WWTPs). A large proportion (>30%) of monitoring studies in WWTPs were conducted in China, followed by Europe (30%) and North America (16%), whereas information is generally lacking for other parts of the world, including most of the developing countries. Short and long-chain perfluoroalkyl acids (PFAAs) were widely detected in both the influents (up to 1,000 ng/L) and effluents (15 to >1,500 ng/L) of WWTPs. To date, limited data is available regarding levels of PFAS precursors and ultra-short chain PFAS in WWTPs. Most WWTPs exhibited low removal efficiencies for PFAS, and many studies reported an increase in the levels of PFAAs after wastewater treatment. The analysis of the fate of various classes of PFAS at different wastewater treatment stages (aerobic and/aerobic biodegradation, photodegradation, and chemical degradation) revealed biodegradation as the primary mechanism responsible for the transformation of PFAS precursors to PFAAs in WWTPs. Remediation studies at full scale and laboratory scale suggest advanced processes such as adsorption using ion exchange resins, electrochemical degradation, and nanofiltration are more effective in removing PFAS (~95–100%) than conventional processes. However, the applicability of such treatments for real-world WWTPs faces significant challenges due to the scaling-up requirements, mass-transfer limitations, and management of treatment by-products and wastes. Combining more than one technique for effective removal of PFAS, while addressing limitations of the individual treatments, could be beneficial. Considering environmental concentrations of PFAS, cost-effectiveness, and ease of operation, nanofiltration followed by adsorption using wood-derived biochar and/or activated carbons could be a viable option if introduced to conventional treatment systems. However, the large-scale applicability of the same needs to be further verified.

Resource Type

Journal Article

Publication Year



Lenka, Swadhina Priyadarshini; Kah, Melanie; Padhye, Lokesh P.



Relevant Country

China, United States

Specific Contaminants

Other Chemicals, Ethyl perfluorooctane sulfonamidoacetic acid, Perfluorooctane sulfonamide, Perfluorooctane sulfonamidoacetic acid, Perfluorooctane sulfonamidoethanol, Perfluoroalkyl acids, Perfluorobutyric acid, Perfluorobutanesulfonate/ sulfonic acid, Perfluorocarboxylic acid, Perfluorodecanoic acid, Perfluorodecylphosphonic acid, Perfluorodecane sulfonate/sulfonic acid, Perfluoroheptanoic acid, Perfluoroheptanesulfonate/ sulfonic acid, Perfluorohexanoic acid, Perfluorohexanephosphonic acid, Perfluorohexanesulfonate/ sulfonic acid, Perfluorononanoic acid, Perfluorooctanoic acid, Perfluorooctanephosphonic acid, Perfluorooctane sulfonate/sulfonic acid, Perfluoropentanoic acid, Perfluororpentanesulfonate/ sulfonic acid, Perfluoropropionic acid, Perfluorosulfonate/sulfonic acid, Perfluorooctane sulfonyl fluoride, Poly tetrafluoroethylene, Poly vinylidene fluoride-co chlorotrifluoroethylene, Poly vinylidene fluoride-co hexafluropropylene, Trifluoroacetic acid, Trifluoromethane sulfonic acid

University Affiliation

The University of Auckland

Business Connect Takeaways

The study investigates the mechanism of fluoride removal by aluminum-based coagulants, specifically AlCl3 and Al13. The results suggest that the defluorination efficiency of these coagulants is influenced by the speciation of aluminum, which affects the formation of aluminum-fluoride complexes and their subsequent removal from the water.
The study finds that Al13 has a higher defluorination efficiency compared to AlCl3, which could make it a more suitable coagulant for treating water with high fluoride concentrations. The results suggest that Al13 can form more stable aluminum-fluoride complexes, which are more effectively removed from the water during coagulation.
The study provides insights into the role of pH in defluorination by aluminum-based coagulants. The results suggest that the optimal pH range for defluorination by Al13 is wider compared to AlCl3, which could make it more effective in treating water with varying pH levels. The study also highlights the importance of optimizing the dosage of coagulants to achieve maximum defluorination efficiency.

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