A batch-scale plasma reactor (1.5 L) was used to rapidly and effectively degrade poly- and perfluoroalkyl substances (PFAS) from ion exchange (IX) brine solution obtained from ECT<sub>2</sub> Inc. In the IX brine solutions, numerous PFAS were detected in a wide concentration range (~0.002 to 4 mg/L; total oxidizable precursors (TOP) ~46 mg/L, and total fluorine by combustion ion chromatography (CIC) ~99 mg F/L). The mean concentration of total perfluoroalkyl acids (PFAAs) (5 perfluorocarboxylic acids (PFCAs) and 4 perfluoroalkyl sulfonates (PFSAs) was 1.1 ± 1.2 mg/L (range 0.002 to 4 mg/L), and the concentrations of two identified PFAS precursors: 6:2 fluorotelomere sulfonate (6:2 FTS) and 4:2 fluorotelomere sulfonate (4:2 FTS) were 3.3 and 0.11 mg/L, respectively.<br/>Plasma-based water treatment resulted in rapid perfluorooctanoic acids (PFOA) (50 mg/L) degradation from 1.5 L synthetic water sample with faster rates in higher conductivity solutions (80 &gt; 60 &gt; 40 &gt; 22 mS/cm). A faster rate of PFOA removal was found for higher delivered power (capacitance values 12 &gt;8 &gt; 4 nF). Several linear chain perfluoroalkyl carboxylic acids (PFCAs) (C4 to C7) were identified as byproducts of PFOA treatment, whose concentrations first increased and then decreased during 60 minutes of plasma treatment except for perfluorobutanoic acid (PFBA) whose concentration did not decrease during treatment. At the end of the treatment, 60% defluorination of PFOA was achieved with the remainder of &lt;1% F associated with remaining PFOA and its organic byproducts, and rest PFOA could be sorbed onto reactor walls and submerged diffuser. In real IX brine samples, the concentrations of long-chain PFAS (PFOA and PFHxS) were efficiently decreased by &gt;99% in 120 minutes. Among the short-chain PFAAs near 100% removal of PFHpA, 75% removal of PFPeS, 60% removal of PFBS, 55% removal of PFHxA, and negligible removal (&lt;5%) of PFPeA and PFBA was achieved. Among the precursors, complete removal for 6:2 FTS and 67% removal for 4:2 FTS was found. Overall, 76% of the TOP present in the IX brine sample was removed or chemically transformed to PFAAs during the treatment. The fluoride concentration increased from 1 to 12 mg/L after plasma treatment, indicating significant defluorination of PFAAs and their precursors. Overall, the results indicate that plasma-based water treatment is a viable technology for the treatment of PFAS-contaminated IX brine solutions.

Rapid removal of poly- and perfluorinated compounds from high conductivity water in a batch-scale plasma reactor

Macromolecular Chemistry: The Second Century

[Author Benefits](https://scimeetings.acs.org/?utm_source=pubs_content_marketing&utm_medium=website&utm_campaign=0320_MCF_NPI_Launch_Spring_Homepage&ref=pubs_content_marketing)

[How to use SciMeetings](https://storage.googleapis.com/dl.morressier.com/acs/SciMeetings-ACSSpring2020-HowToGuide_M3020-Final.pdf)

[Frequently Asked Questions](https://storage.googleapis.com/dl.morressier.com/acs/SciMtng_ACSNMSp2020_FAQ_M3120_Final.pdf)

ACS Spring 2020 National Meeting & Expo

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.