Kinetic and mechanistic insights into the abatement of clofibric acid by integrated UV/ozone/peroxydisulfate process: A modeling and theoretical study

Wenlei Qin; Zhuang Lin; Huiyu Dong; Xiangjuan Yuan; Zhimin Qiang; Shaogang Liu; Dongsheng Xia

doi:10.1016/j.watres.2020.116336

Kinetic and mechanistic insights into the abatement of clofibric acid by integrated UV/ozone/peroxydisulfate process: A modeling and theoretical study

Water Res. 2020 Nov 1:186:116336. doi: 10.1016/j.watres.2020.116336. Epub 2020 Aug 24.

Authors

Wenlei Qin¹, Zhuang Lin², Huiyu Dong³, Xiangjuan Yuan⁴, Zhimin Qiang³, Shaogang Liu⁵, Dongsheng Xia⁶

Affiliations

¹ School of Environmental Engineering, Wuhan Textile University, No.1 Sunshine Avenue, Wuhan 430200, China; Research Center for Eco-Environmental Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 18 Shuang-qing Road, Beijing 100085, China.
² School of Environmental Engineering, Wuhan Textile University, No.1 Sunshine Avenue, Wuhan 430200, China.
³ Research Center for Eco-Environmental Sciences, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 18 Shuang-qing Road, Beijing 100085, China.
⁴ School of Environmental Engineering, Wuhan Textile University, No.1 Sunshine Avenue, Wuhan 430200, China; Engineering Research Center for Clean Production of Textile Dyeing and Printing, Ministry of Education, No.1 Sunshine Avenue, Wuhan 430200, China. Electronic address: yuanxiangjuan1986@outlook.com.
⁵ School of Chemistry and Chemical Engineering, Guangxi University for Nationalities, 158 Da-xue Road, Nanning 530008, China.
⁶ School of Environmental Engineering, Wuhan Textile University, No.1 Sunshine Avenue, Wuhan 430200, China; Engineering Research Center for Clean Production of Textile Dyeing and Printing, Ministry of Education, No.1 Sunshine Avenue, Wuhan 430200, China. Electronic address: dongsheng_xia@wtu.edu.cn.

PMID: 32889366
DOI: 10.1016/j.watres.2020.116336

Abstract

The feasibility of integrated UV/ozone (O₃)/peroxydisulfate (PDS) process for abatement of clofibric acid (CA) was systematically explored in this study with focus on the kinetic simulation and oxidation mechanisms. The results indicated the UV/O₃/PDS process was of prominent treatment capability with pseudo-first-order rate constant of CA degradation increased by 65.9% and 86.0% compared to UV/O₃ and UV/PDS processes, respectively. A chemical kinetic model was developed and successfully employed to predict CA elimination as well as the specific contributions of UV, hydroxyl radical (^•OH) and sulfate radical (SO₄^•-) under different PDS dosage, pH, natural organic matters, bicarbonate and chloride conditions in UV/O₃/PDS process. According to quantum chemical calculation, radical addition on ortho site of isopropoxy substituent and single electron transfer were corroborated to be the dominant reaction channels for the oxidation of CA by ^•OH and SO₄^•-, respectively. Additionally, the reactive sites and transformation pathways of CA were proposed via Fukui function calculation and UPLC-Q-TOF-MS analysis. Moreover, the performance of UV/O₃/PDS process was further evaluated with regard to the energy demand and bromate formation. This study first proposed a kinetic model in UV/O₃/PDS process and elucidated the regioselectivity and products distribution of CA during oxidative treatment.

Keywords: Kinetic modeling; Ozone; Peroxydisulfate; Quantum chemical calculation; UV.

MeSH terms

Clofibric Acid
Hydrogen Peroxide
Kinetics
Models, Theoretical
Oxidation-Reduction
Ozone*
Ultraviolet Rays
Water Pollutants, Chemical* / analysis
Water Purification*

Substances

Water Pollutants, Chemical
Clofibric Acid
Ozone
Hydrogen Peroxide