Removal of perfluoroalkyl and polyfluoroalkyl substances in potable reuse systems. (1st November 2018)

• Record Type: Journal Article
• Authors: Glover, Caitlin M.; Quiñones, Oscar; Dickenson, Eric R.V.
• Is Part Of: Water research. Volume 144(2018)
• Page Start: 454
• Page End: 461
• Publication Date: 2018-11-01
• Subjects: Perfluoroalkyl and polyfluoroalkyl substances (PFASs) -- Perfluoroalkyl acid precursors -- Total oxidizable precursor assay -- Potable reuse -- Advanced treatment trains; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2018.07.018
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are a group of persistent contaminants that have been identified throughout the aquatic environment. In this study, ten targeted perfluoroalkyl acids (PFAAs), three targeted PFAA precursors, and non-targeted PFAA precursors were monitored in four full- and pilot-scale potable reuse plants at each stage of advanced treatment. Non-targeted PFAA precursors were quantified by applying a total oxidizable precursor assay in which PFAA precursors are oxidized by hydroxyl radicals to targeted PFAAs. Two of the potable reuse systems had membrane-based treatments with reverse osmosis and UV-advanced oxidation (RO-UV/AOP) and two used ozone, biological activated carbon filtration and granular activated carbon adsorption (O3 -BAC-GAC). The total targeted PFAAs in the four tertiary effluents, the influent sources for the potable reuse systems, ranged from 52 to 227 ng/L with non-targeted PFAA precursors accounting for 30–67% of total PFASs on a molar basis. The RO-UV/AOP treatment trains reduced PFAAs and PFAA precursors to below their method reporting limits through the barrier provided by RO. The O3 -BAC-GAC based treatment trains reduced, but did not completely remove PFAAs or PFAA precursors and the PFASs present in the product water were primarily shorter-chain PFAAs, some of which lack human health guidance values for drinking water. The relative fraction of targeted shorter-chain PFAAs increased after each treatment step indicating that there was preferential removal of the PFAA precursors and longer-chain PFAAs. This study provides new insight on the concentrations and treatment of PFAA precursors through potable reuse treatment systems. Highlights: PFAAs and PFAA precursors were measured in four potable reuse treatment trains. PFAA precursors were between 30 and 67% of the total PFASs in tertiary effluents. Long-chain PFAAs and PFAA precursors were preferentially removed in O3 -BAC-GAC. Microfiltration and ultrafiltration removed PFAA precursors, but released PFAAs. All treatment trains reduced PFAAs below known guideline values.