Reductive defluorination of Perfluorooctanesulfonic acid (PFOS) by hydrated electrons generated upon UV irradiation of 3-Indole-acetic-acid in 12-Aminolauric-Modified montmorillonite

WATER RESEARCH

卷:200

Article

Kugler, Alex¹  Dong, Hailiang¹  Li, Chen²  Gu, Cheng²  Schaefer, Charles E.³  Choi, Youn Jeong⁴  Tran, Danielle³  Spraul, Morgan³  Higgins, Christopher P.⁴ 

[1] Miami Univ, Dept Geol & Environm Earth Sci, Oxford, OH 45056 USA

[2] Nanjing Univ, Sch Environm, State Key Lab Pollut Control & Resource Reuse, Nanjing 210023, Peoples R China

[3] CDM Smith, Edison, NJ USA

[4] Colorado Sch Mines, Dept Civil & Environm Engn, Golden, CO 80401 USA

关键词: ALA;    degradation;    IAA;    montmorillonite;    PFOS;    sorption;   

DOI  :  10.1016/j.watres.2021.117221

来源: Elsevier

【 摘 要 】

Per-and poly-fluoroalkyl substances (PFASs) are a class of persistent compounds that are resistant to degradation. Here we developed an effective method of degrading perfluorooctanesulfonate (PFOS) by hydrated electrons (e(aq)( -)) that are generated from 3-indole-acetic-acid (IAA) upon UV irradiation. The method takes advantage of spatial proximity of IAA and PFOS by their co-sorption to an organic polymer, 12-aminolauric acid (ALA), which was pre-intercalated into the interlayer space of an expandable clay mineral, montmorillonite. The interlayer spacing of this clay nanocomposite is greatly expanded relative to unmodified montmorillonite. The maximum adsorption capacity of IAA and PFOS is 168 and 1550 mmol/kg, respectively. This process achieved 40-70% defluorination of a 10 ppm PFOS solution at neutral pH in a 325 mL vessel. The presence of bicarbonate and chloride ions, or natural groundwater showed a minimal impact on PFOS degradation. Based on identification of prominent degradation products, a degradation pathway is proposed, where the primary degradation process is breakage of the C-F bonds (with fluorine replaced by hydrogen), with some cleavage of the C-C bond. This approach provides an alternative for treating concentrated PFAS solutions under ambient conditions. (C) 2021 Elsevier Ltd. All rights reserved.

【 授权许可】

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