Pilot Assessment of Impacts of Ozone and Ozone/Hydrogen Peroxide Treatment on the Fate of Per- and Polyfluoroalkyl Substances and Precursors

Xiaoyue Xin; Juhee Kim; ShihChi Weng; Ching-Hua Huang

doi:10.1021/acsestwater.4c00565

Pilot Assessment of Impacts of Ozone and Ozone/Hydrogen Peroxide Treatment on the Fate of Per- and Polyfluoroalkyl Substances and Precursors

ACS ES T Water. 2024 Sep 25;4(10):4545-4555. doi: 10.1021/acsestwater.4c00565. eCollection 2024 Oct 11.

Authors

Xiaoyue Xin¹, Juhee Kim², ShihChi Weng³, Ching-Hua Huang¹

Affiliations

¹ School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States.
² Department of Civil, Environmental and Construction Engineering, University of Hawaìi at Ma̅noa, Honolulu, Hawaii 96822, United States.
³ Department of Water Resources, Gwinnet County Government, Lawrenceville, Georgia 30045, United States.

Abstract

Per- and polyfluoroalkyl substances (PFAS) make up a large class of anthropogenic micropollutants prevalent in wastewater. Oxidative processes commonly used in wastewater potable reuse treatment may affect transformation of PFAS precursors, leading to elevated concentrations of perfluorinated alkyl acids (PFAAs) that are significant health concerns. This work conducted a pilot-scale investigation to assess the influence of ozonation (O₃) and ozone/hydrogen peroxide (O₃/H₂O₂) advanced oxidation process (AOP), respectively, on the fate of PFAS in a wastewater effluent subjected to reuse. The study evaluated 40 target PFAS and associated precursors [based on the total oxidizable precursor (TOP) assay] under various treatment conditions, including different ozone doses (1.0-4.0 mg·L^-1), H₂O₂ doses (0-0.20 mg·L^-1), and contact time (0-20 min). Results indicated that short-chain (C3-C7) PFAAs dominated in concentrations, while overall PFAA concentrations were elevated by both oxidative treatment processes, particularly after high-dose ozonation treatment. TOP assays revealed that there were considerable amounts of PFAA precursors in the reuse wastewater, and their concentrations were decreased after the oxidative treatment with an increase of some of the PFAAs. This pilot study demonstrated that ozone and ozone-based AOP treatments can have a moderate influence on the transformation of PFAS and increase in PFAA levels under practical conditions.