Behaviour and fate of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in drinking water treatment: A review

• Published in: Water research (Oxford) 2014-03, Vol.50, p.318-340
• Main Authors: Rahman, Mohammad Feisal, Peldszus, Sigrid, Anderson, William B.
• Format: Article
• Language: English
• Subjects: Activated carbon; Alkanesulfonic Acids - chemistry; Alkanesulfonic Acids - isolation & purification; Applied sciences; Biodegradation, Environmental; Drinking Water - chemistry; Drinking water and swimming-pool water. Desalination; Drinking water treatment; Exact sciences and technology; Fluorocarbons - chemistry; Fluorocarbons - isolation & purification; Humans; Ion exchange; Membrane filtration; PFASs; PFCs; PFOA/PFOS; Pollution; Water Purification - methods; Water treatment and pollution
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2013.10.045

This article reviews perfluoroalkyl and polyfluoroalkyl substance (PFAS) characteristics, their occurrence in surface water, and their fate in drinking water treatment processes. PFASs have been detected globally in the aquatic environment including drinking water at trace concentrations and due, in part, to their persistence in human tissue some are being investigated for regulation. They are aliphatic compounds containing saturated carbon–fluorine bonds and are resistant to chemical, physical, and biological degradation. Functional groups, carbon chain length, and hydrophilicity/hydrophobicity are some of the important structural properties of PFASs that affect their fate during drinking water treatment. Full-scale drinking water treatment plant occurrence data indicate that PFASs, if present in raw water, are not substantially removed by most drinking water treatment processes including coagulation, flocculation, sedimentation, filtration, biofiltration, oxidation (chlorination, ozonation, AOPs), UV irradiation, and low pressure membranes. Early observations suggest that activated carbon adsorption, ion exchange, and high pressure membrane filtration may be effective in controlling these contaminants. However, branched isomers and the increasingly used shorter chain PFAS replacement products may be problematic as it pertains to the accurate assessment of PFAS behaviour through drinking water treatment processes since only limited information is available for these PFASs. Reported removal of PFOA at full-scale drinking water treatment plants. [Display omitted] •Full-scale data indicate that conventional drinking water processes fail to remove PFASs.•Chlorination, ozonation, advanced oxidation processes ineffective for PFAS removal.•Granular activated carbon will remove PFASs but may need frequent reactivation.•NF/RO will achieve high rejections except for some low molecular weight PFASs.•Ion exchange promising but less frequently used for drinking water treatment.