Electrochemical Transformations of Perfluoroalkyl Acid (PFAA) Precursors and PFAAs in Groundwater Impacted with Aqueous Film Forming Foams.

Published

Journal Article

While oxidative technologies have been proposed for treatment of waters impacted by aqueous film forming foams (AFFFs), information is lacking regarding the transformation pathways for the chemical precursors to the perfluoroalkyl acids (PFAAs) typically present in such waters. This study examined the oxidative electrochemical treatment of poly- and perfluoroalkyl substances (PFASs) for two AFFF-impacted groundwaters. The bulk pseudo first order rate constant for PFOA removal was 0.23 L h-1 A-1; for PFOS, this value ranged from 0.084 to 0.23 L h-1 A-1. Results from the first groundwater studied suggested a transformation pathway where sulfonamide-based PFASs transformed to primarily perfluorinated sulfonamides and perfluorinated carboxylic acids (PFCAs), with subsequent defluorination of the PFCAs. Transient increases in the perfluorinated sulfonamides and PFCAs were observed. For the second groundwater studied, no transient increases in PFAAs were measured, despite the presence of similarly structured suspected PFAA precursors and substantial defluorination. For both waters, suspected precursors were the primary sources of the generated fluoride. Assessment of precursor compound transformation noted the formation of keto-perfluoroalkanesulfonates only in the second groundwater. These results confirm that oxidation and defluorination of suspected PFAA precursors in the second groundwater underwent transformation via a pathway different than that of the first groundwater, which was not captured by total oxidizable precursor assay.

Full Text

Duke Authors

Cited Authors

  • Schaefer, CE; Choyke, S; Ferguson, PL; Andaya, C; Burant, A; Maizel, A; Strathmann, TJ; Higgins, CP

Published Date

  • September 2018

Published In

Volume / Issue

  • 52 / 18

Start / End Page

  • 10689 - 10697

PubMed ID

  • 30130962

Pubmed Central ID

  • 30130962

Electronic International Standard Serial Number (EISSN)

  • 1520-5851

International Standard Serial Number (ISSN)

  • 0013-936X

Digital Object Identifier (DOI)

  • 10.1021/acs.est.8b02726

Language

  • eng