Degradation of contaminants of emerging concern by UV/H2O2 for water reuse: Kinetics, mechanisms, and cytotoxicity analysis

Ying Huang; Minghao Kong; Scott Coffin; Kristin H Cochran; Danielle C Westerman; Daniel Schlenk; Susan D Richardson; Lecheng Lei; Dionysios D Dionysiou

doi:10.1016/j.watres.2020.115587

Degradation of contaminants of emerging concern by UV/H₂O₂ for water reuse: Kinetics, mechanisms, and cytotoxicity analysis

Water Res. 2020 May 1:174:115587. doi: 10.1016/j.watres.2020.115587. Epub 2020 Feb 4.

Authors

Ying Huang¹, Minghao Kong², Scott Coffin³, Kristin H Cochran⁴, Danielle C Westerman⁴, Daniel Schlenk⁵, Susan D Richardson⁴, Lecheng Lei⁶, Dionysios D Dionysiou⁷

Affiliations

¹ Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH, 45221, United States; College of Chemical and Biological Engineering, Key Laboratory of Biomass Chemical Engineering of Ministry of Education, Zhejiang University, Zhejiang, 310012, China.
² Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH, 45221, United States.
³ Department of Environmental Sciences, University of California, Riverside, CA, 92521, United States; California State Water Resources Control Board, Sacramento, CA, 95814, United States.
⁴ Department of Chemistry and Biochemistry, University of South Carolina, Columbia, SC, 29208, United States.
⁵ Department of Environmental Sciences, University of California, Riverside, CA, 92521, United States; Institute of Environmental Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
⁶ College of Chemical and Biological Engineering, Key Laboratory of Biomass Chemical Engineering of Ministry of Education, Zhejiang University, Zhejiang, 310012, China.
⁷ Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH, 45221, United States. Electronic address: dionysios.d.dionysiou@uc.edu.

PMID: 32097806
DOI: 10.1016/j.watres.2020.115587

Abstract

Advanced oxidation using UV and hydrogen peroxide (UV/H₂O₂) has been widely applied to degrade contaminants of emerging concern (CECs) in wastewater for water reuse. This study investigated the degradation kinetics of mixed CECs by UV/H₂O₂ under variable H₂O₂ doses, including bisphenol A, estrone, diclofenac, ibuprofen, and triclosan. Reverse osmosis (RO) treated water samples from Orange County Water District's Groundwater Replenishment System (GWRS) potable reuse project were collected on different dates and utilized as reaction matrices with spiked additions of chemicals (CECs and H₂O₂) to assess the application of UV/H₂O₂. Possible degradation pathways of selected CECs were proposed based on high resolution mass spectrometry identification of transformation products (TPs). Toxicity assessments included cytotoxicity, aryl hydrocarbon receptor-binding activity, and estrogen receptor-binding activity, in order to evaluate potential environmental impacts resulting from CEC degradation by UV/H₂O₂. Cytotoxicity and estrogenic activity were significantly reduced during the degradation of mixed CECs in Milli-Q water by UV/H₂O₂ with high UV fluence (3200 mJ cm^-2). However, in GWRS RO-treated water samples collected in April 2017, the cytotoxicity and estrogen activity of spiked CEC-mixture after UV/H₂O₂ treatment were not significantly eliminated; this might be due to the high concentration of target CEC and their TPs, which was possibly affected by the varied quality of the secondary treatment influent at this facility such as sewer-shed and wastewater discharges. This study aimed to provide insight on the impacts of post-UV/H₂O₂ CECs and TPs on human and ecological health at cellular level.

Keywords: Contaminants of emerging concern; Cytotoxicity; Transformation products; UV/H(2)O(2) AOP; Water reuse.

MeSH terms

Humans
Hydrogen Peroxide
Kinetics
Oxidation-Reduction
Ultraviolet Rays
Wastewater
Water
Water Pollutants, Chemical*
Water Purification*

Substances

Waste Water
Water Pollutants, Chemical
Water
Hydrogen Peroxide