Defluorination of Per- and Polyfluoroalkyl Substances (PFASs) with Hydrated Electrons: Structural Dependence and Implications to PFAS Remediation and Management

Published on Apr 2, 2019in Environmental Science & Technology7.149
· DOI :10.1021/acs.est.8b06648
Michael J. Bentel1
Estimated H-index: 1
(UCR: University of California, Riverside),
Yaochun Yu3
Estimated H-index: 3
(UIUC: University of Illinois at Urbana–Champaign)
+ 4 AuthorsJinyong Liu9
Estimated H-index: 9
(UCR: University of California, Riverside)
This study investigates critical structure–reactivity relationships within 34 representative per- and polyfluoroalkyl substances (PFASs) undergoing defluorination with UV-generated hydrated electrons. While CnF2n+1–COO– with variable fluoroalkyl chain lengths (n = 2 to 10) exhibited a similar rate and extent of parent compound decay and defluorination, the reactions of telomeric CnF2n+1–CH2CH2–COO– and CnF2n+1–SO3– showed an apparent dependence on the length of the fluoroalkyl chain. Cross comparison of experimental results, including different rates of decay and defluorination of specific PFAS categories, the incomplete defluorination from most PFAS structures, and the surprising 100% defluorination from CF3COO–, leads to the elucidation of new mechanistic insights into PFAS degradation. Theoretical calculations on the C–F bond dissociation energies (BDEs) of all PFAS structures reveal strong relationships among (i) the rate and extent of decay and defluorination, (ii) head functional groups, (iii) fluor...
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Cited By3
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#2Haodong Ji (AU: Auburn University)H-Index: 4
Last. Dongye Zhao (AU: Auburn University)H-Index: 40
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Abstract Perfluorooctanoic acid (PFOA) has been widely detected in aquatic systems. Yet, cost-effective technologies for degrading PFAS have been lacking. We prepared and tested an adsorptive photocatalyst consisting of iron (hydr)oxides and carbon spheres (FeO/CS) through a one-step hydrothermal process. Characterization results revealed that the presence of carbon spheres affected the crystal formation of iron (hydr)oxides, and resulted in mutually modified mixed phases ferrihydrite and carbon...
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The development of efficient technology for perfluorooctanoic acid (PFOA) treatment has prompted much concern in water environmental fields, due to its global distribution and threats to ecosystems. In this study, a new method for reductive defluorination of PFOA under visible light (VL) was established by using Pt-Bi2O4 as photocatalysts and KI as electron donors. The defluorination process in water was found to undergo photocatalytic reductive pathway, in which the photo-generated e− played th...
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Abstract Perfluorooctanoic acid (PFOA) from contaminated soil accumulates in higher organisms, and causes health risks to humans. In this research, 71 % of the PFOA was degraded, of which 51 % was decomposed into short chain by-products, 19 % mineralized, and 1 % volatilized with 30 kV of voltage, 50 Hz of discharge frequency, 1 % of soil moisture, 300 ppm of PFOA concentration and 6.3 of soil pH using pulsed positive discharge plasma. From a series of experiments, electrons were identified as t...
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Poly- and perfluoroalkyl substances (PFAS) are a group of fluorinated organic anthropogenic chemicals that are resistant to degradation. In this paper, non-equilibrium, reverse vortex gliding arc plasma (GAP) discharges in air, nitrogen (N2), and pure oxygen (O2) gases were investigated for the removal of perfluoroalkyl carboxylates (PFCA), perfluoroalkyl sulfonates (PFSA), and fluorotelomer sulfonates (FtS) from liquid solutions in a 1-liter treatment system. At initial concentrations ranging f...
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Abstract The increasing occurrence of chemically resistant per- and poly-fluoroalkyl substances (PFASs) in the natural environment, animal tissues and even the human body poses a significant health risk. Temporal trend studies on water, sediments, bird, fish, marine mammal and the human show that the exposure of PFAS has significantly increased over the last 20-30 years. Different physical, biological and chemical treatment processes have been investigated for PFAS removal from water. However, th...
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Hydrothermal liquefaction (HTL) is a promising technology for recovering energy from wastewater treatment sludge in the form of liquid biofuel, but there are concerns about the fate of persistent organic contaminants sorbed to the sludge. This study monitored the fate and degradation of representative per- and polyfluoroalkyl substances (PFAS) in water and sorbed to a municipal wastewater treatment sludge during HTL reactions. The yield and carbon mass content of the biocrude oil product from HT...