Your browser doesn't support javascript.
loading
Degradation of Per- and Polyfluoroalkyl Substances with Hydrated Electrons: A New Mechanism from First-Principles Calculations.
Biswas, Sohag; Yamijala, Sharma S R K C; Wong, Bryan M.
Afiliación
  • Biswas S; Department of Chemical & Environmental Engineering, Materials Science & Engineering Program, Department of Physics & Astronomy, and Department of Chemistry, University of California-Riverside, Riverside, California 92521, United States.
  • Yamijala SSRKC; Department of Chemistry and Center for Atomistic Modelling and Materials Design, Indian Institute of Technology-Madras, Chennai 6000036, India.
  • Wong BM; Department of Chemical & Environmental Engineering, Materials Science & Engineering Program, Department of Physics & Astronomy, and Department of Chemistry, University of California-Riverside, Riverside, California 92521, United States.
Environ Sci Technol ; 56(12): 8167-8175, 2022 06 21.
Article en En | MEDLINE | ID: mdl-35481774
Per- and polyfluoroalkyl substances (PFASs) are synthetic contaminants found in drinking groundwater sources and a wide variety of consumer products. Because of their adverse environmental and human health effects, remediation of these persistent compounds has attracted significant recent attention. To gain mechanistic insight into their remediation, we present the first ab initio study of PFAS degradation via hydrated electrons─a configuration that has not been correctly considered in previous computational studies up to this point. To capture these complex dynamical effects, we harness ab initio molecular dynamics (AIMD) simulations to probe the reactivities of perfluorooctanoic (PFOA) and perfluorooctane sulfonic acid (PFOS) with hydrated electrons in explicit water. We complement our AIMD calculations with advanced metadynamics sampling techniques to compute free energy profiles and detailed statistical analyses of PFOA/PFOS dynamics. Although our calculations show that the activation barrier for C-F bond dissociation in PFOS is three times larger than that in PFOA, all the computed free energy barriers are still relatively low, resulting in a diffusion-limited process. We discuss our results in the context of recent studies on PFAS degradation with hydrated electrons to give insight into the most efficient remediation strategies for these contaminants. Most importantly, we show that the degradation of PFASs with hydrated electrons is markedly different from that with excess electrons/charges, a common (but largely incomplete) approach used in several earlier computational studies.
Asunto(s)
Palabras clave

Texto completo: 1 Bases de datos: MEDLINE Asunto principal: Contaminantes Químicos del Agua / Agua Subterránea / Ácidos Alcanesulfónicos / Fluorocarburos Límite: Humans Idioma: En Revista: Environ Sci Technol Año: 2022 Tipo del documento: Article País de afiliación: Estados Unidos

Texto completo: 1 Bases de datos: MEDLINE Asunto principal: Contaminantes Químicos del Agua / Agua Subterránea / Ácidos Alcanesulfónicos / Fluorocarburos Límite: Humans Idioma: En Revista: Environ Sci Technol Año: 2022 Tipo del documento: Article País de afiliación: Estados Unidos