Enhanced degradation of iohexol in water by CuFe2O4 activated peroxymonosulfate: Efficiency, mechanism and degradation pathway

Shuyu Wang; Zhonglin Chen; Pengwei Yan; Tianhao She; Weiqiang Wang; Lanbo Bi; Jing Kang; Jimin Shen; Xueyan Li; Linlu Shen; Yizhen Cheng

doi:10.1016/j.chemosphere.2021.133198

Enhanced degradation of iohexol in water by CuFe₂O₄ activated peroxymonosulfate: Efficiency, mechanism and degradation pathway

Chemosphere. 2022 Feb:289:133198. doi: 10.1016/j.chemosphere.2021.133198. Epub 2021 Dec 8.

Authors

Shuyu Wang¹, Zhonglin Chen¹, Pengwei Yan², Tianhao She¹, Weiqiang Wang¹, Lanbo Bi¹, Jing Kang³, Jimin Shen⁴, Xueyan Li⁵, Linlu Shen¹, Yizhen Cheng¹

Affiliations

¹ State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China.
² State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China. Electronic address: yanpengwei@stu.hit.edu.cn.
³ State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China. Electronic address: jingkanghit@163.com.
⁴ State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China; Jiangsu Provincial Key Laboratory of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, PR China. Electronic address: shenjimin@hit.edu.cn.
⁵ Jiangsu Provincial Key Laboratory of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou, 215009, PR China.

PMID: 34890616
DOI: 10.1016/j.chemosphere.2021.133198

Abstract

Iohexol as an iodinated X-ray contrast agent is widely used, and it is the potential precursor for toxic iodinated disinfection by-products in the disinfection process. In this study, a series of CuFe₂O₄ catalysts were prepared by sol-gel method with different molar ratios of total metal cations to citric acid ([Meⁿ⁺]_T/CA) and employed as heterogeneous catalysts to activate peroxymonosulfate (PMS) for the removal of iohexol. The catalysts were characterized by various technologies, and the effect of [Meⁿ⁺]_T/CA molar ratio on the catalysts' properties was explored. The CuFe₂O₄ synthesized with [Meⁿ⁺]_T/CA molar ratio of 1:1 showed the best catalytic activity to PMS, and 95.0% of 1.0 mg/L iohexol was removed within 15 min by using 50 mg/L CuFe₂O₄ and 20 mg/L PMS. The quenching experiment and electron spin resonance (ESR) spectra indicated the generation of SO₄^- and OH in the CuFe₂O₄/PMS system, and the quantity experiments revealed that the generation concentration of SO₄^- was ten times higher than that of OH. The generation mechanism of SO₄^- and ·OH were investigated by ATR-FTIR and X-ray photoelectron spectroscopy (XPS) spectra. The effects of catalyst dosage, PMS and iohexol concentration on the removal of iohexol were studied, and various water matrix factors including solution pH, natural organic matter (NOM) concentration and inorganic ions were also considered. Based on the twelve intermediate products of iohexol detected by UPLC-QTOF/MS, the degradation pathway was proposed. The high catalytic activity and reusability of CuFe₂O₄ indicated that CuFe₂O₄ activating PMS is an effective and sustainable way for the treatment of iohexol.

Keywords: CuFe(2)O(4)nanoparticles; Degradation mechanism; Iohexol; Peroxymonosulfate; SO(4)(·-) and ·OH.

MeSH terms

Catalysis
Iohexol*
Peroxides
Water*

Substances

Peroxides
Water
peroxymonosulfate
Iohexol