Kinetic and mechanistic investigation into odorant haloanisoles degradation process by peracetic acid combined with UV irradiation

Kejia Zhang; Yulong San; Cong Cao; Tuqiao Zhang; Cheng Cen; Zhang Li; Jie Fu

doi:10.1016/j.jhazmat.2020.123356

Kinetic and mechanistic investigation into odorant haloanisoles degradation process by peracetic acid combined with UV irradiation

J Hazard Mater. 2021 Jan 5:401:123356. doi: 10.1016/j.jhazmat.2020.123356. Epub 2020 Jul 1.

Authors

Kejia Zhang¹, Yulong San¹, Cong Cao², Tuqiao Zhang¹, Cheng Cen¹, Zhang Li³, Jie Fu⁴

Affiliations

¹ College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China.
² College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China; Hangzhou Audit Office, Hangzhou 310016, China.
³ School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
⁴ School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China. Electronic address: jiefu@hust.edu.cn.

PMID: 32652422
DOI: 10.1016/j.jhazmat.2020.123356

Abstract

This study reported the kinetics and mechanism of degradation of odorant haloanisoles by peracetic acid combined with UV irradiation (PAA/UV). The removal efficiency of haloanisoles by PAA/UV was more than 92 % after 1 h reaction at pH 5, 25 °C, [HAs] =50 μg/L and [PAA] = 10 mg/L. The degradation of haloanisoles was fitted by the first-order kinetic model, and the rate constants of various haloanisoles followed the order: 2,4,6-tribromoanisole (2,4,6-TBA, (9.25 ± 0.71)×10^-2 s^-1) > 2-monochloroanisole (2-MCA, (8.00 ± 0.34)×10^-2 s^-1) > 2,4-dichloroanisole (2,4-DCA, (6.24 ± 0.55)×10^-2 s^-1) > 2,4,6-trichloroanisole (2,4,6-TCA, (5.05 ± 0.04)×10^-2 s^-1). The contribution of PAA (mainly composed of free radicals produced from PAA activation by UV) to the degradation rate of chloroanisoles in PAA/UV process ranged from 24 % to 36 %, while 25 % to the degradation rate of bromoanisole. Direct photolysis contributed much more to the removal of bromoanisole (42 %) than chloroanisoles (9-14 %). The inhibition of tert-butanol on degradation demonstrated the existence of ·OH, and superoxide radical and carbon-centered radicals were also probably existed in PAA/UV process. Combining density functional theory (DFT) calculation and products analysis, the degradation pathway of haloanisoles in PAA/UV process were determined. The odor and toxicity evaluation indicated PAA/UV process could reduce olfactory discomfort and health risk of haloanisoles.

Keywords: Haloanisoles; Odorants; Peracetic acid; Superoxide radical; UV irradiation.

Publication types

Research Support, Non-U.S. Gov't