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dc.contributor.authorPark, Hyunwoong
dc.contributor.authorVecitis, Chad D.
dc.contributor.authorCheng, Jie
dc.contributor.authorDalleska, Nathan F.
dc.contributor.authorMader, Brian T.
dc.contributor.authorHoffmann, Michael R.
dc.date.accessioned2018-01-24T20:13:40Z
dc.date.issued2011
dc.identifier.citationPark, Hyunwoong, Chad D. Vecitis, Jie Cheng, Nathan F. Dalleska, Brian T. Mader, and Michael R. Hoffmann. 2011. “Reductive Degradation of Perfluoroalkyl Compounds with Aquated Electrons Generated from Iodide Photolysis at 254 Nm.” Photochemical & Photobiological Sciences 10 (12): 1945. doi:10.1039/c1pp05270e.en_US
dc.identifier.issn1474-905Xen_US
dc.identifier.urihttp://nrs.harvard.edu/urn-3:HUL.InstRepos:34730507
dc.description.abstractThe perfluoroalkyl compounds (PFCs), perfluoroalkyl sulfonates (PFXS) and perfluoroalkyl carboxylates (PFXA) are environmentally persistent and recalcitrant towards most conventional water treatment technologies. Here, we complete an in depth examination of the UV-254 nm production of aquated electrons during iodide photolysis for the reductive defluorination of six aquated perfluoroalkyl compounds (PFCs) of various headgroup and perfluorocarbon tail length. Cyclic voltammograms (CV) show that a potential of +2.0 V (vs. NHE) is required to induce PFC oxidation and -1.0 V is required to induce PFC reduction indicating that PFC reduction is the thermodynamically preferred process. However, PFCs are observed to degrade faster during UV(254 nm)/persulfate (S2O8 2) photolysis yielding sulfate radicals (E◦ = +2.4 V) as compared to UV(254 nm)/iodide (I) photolysis yielding aquated electrons (E◦ = -2.9 V). Aquated electron scavenging by photoproduced triiodide (I3 - ), which achieved a steady-state concentration proportional to [PFOS]0, reduces the efficacy of the UV/iodide system towards PFC degradation. PFC photoreduction kinetics are observed to be dependent on PFC headgroup, perfluorocarbon chain length, initial PFC concentration, and iodide concentration. From 2 to 12, pH had no observable effect on PFC photoreduction kinetics, suggesting that the aquated electron was the predominant reductant with negligible contribution from the H-atom. A large number of gaseous fluorocarbon intermediates were semi-quantitatively identified and determined to account for ~25% of the initial PFOS carbon and fluorine. Reaction mechanisms that are consistent with kinetic observations are discussed.en_US
dc.description.sponsorshipEngineering and Applied Sciencesen_US
dc.language.isoen_USen_US
dc.publisherRoyal Society of Chemistry (RSC)en_US
dc.relation.isversionofdoi:10.1039/c1pp05270een_US
dash.licenseMETA_ONLY
dc.titleReductive degradation of perfluoroalkyl compounds with aquated electrons generated from iodide photolysis at 254 nmen_US
dc.typeJournal Articleen_US
dc.description.versionVersion of Recorden_US
dc.relation.journalPhotochem. Photobiol. Sci.en_US
dash.depositing.authorVecitis, Chad D.
dash.embargo.until10000-01-01
dc.identifier.doi10.1039/c1pp05270e*
workflow.legacycommentsoap.needmanen_US
dash.contributor.affiliatedVecitis, Chad


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