Activation of sulfite by micron-scale iron-carbon composite for metronidazole degradation: Theoretical and experimental studies

Zixuan Zhao; Yunhe Li; Yuerong Zhou; Yilong Hou; Zhengyi Sun; Wenhao Wang; Jianfeng Gou; Xiuwen Cheng

doi:10.1016/j.jhazmat.2023.130873

Activation of sulfite by micron-scale iron-carbon composite for metronidazole degradation: Theoretical and experimental studies

J Hazard Mater. 2023 Apr 15:448:130873. doi: 10.1016/j.jhazmat.2023.130873. Epub 2023 Jan 28.

Authors

Zixuan Zhao¹, Yunhe Li¹, Yuerong Zhou¹, Yilong Hou¹, Zhengyi Sun¹, Wenhao Wang², Jianfeng Gou³, Xiuwen Cheng⁴

Affiliations

¹ Key Laboratory for Environmental Pollution Prediction and Control, Gansu Province, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, PR China.
² Civil Engineering Department, Yancheng Institute of Technology, Yancheng, Jiangsu 224051, PR China.
³ Key Laboratory for Environmental Pollution Prediction and Control, Gansu Province, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, PR China. Electronic address: goujf@lzu.edu.cn.
⁴ Key Laboratory for Environmental Pollution Prediction and Control, Gansu Province, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou 730000, PR China; Key Laboratory of Pollutant Chemistry and Environmental Treatment, College of Chemistry and Environmental Science, Yili Normal University, Yining 835000, PR China. Electronic address: chengxw@lzu.edu.cn.

PMID: 36731316
DOI: 10.1016/j.jhazmat.2023.130873

Abstract

In recent years, sulfite (S(Ⅳ)), as an alternative to persulfates, has played a crucial role in eliminating antibiotics in wastewater, so there is an urgent need to develop a cheap, environmentally friendly, and effective catalyst. Zero-valent iron (ZVI) has great potential for activated S(Ⅳ) removal of organic pollutants, but its reactivity in water is reduced due to passivation. In this study, a micron-scale iron-carbon composite(mZVI@C-800) prepared via high-temperature calcination was coupled with S(Ⅳ) to degrade metronidazole (MNZ). Under the optimized reaction conditions of mZVI@C-800 dosage of 0.2 g/L and S(Ⅳ) concentration of 0.1 g/L, the MNZ removal rate was up to 81.5 % in acidic and neutral environments. The surface chemical properties of the catalysts were characterized by different analytical techniques, and the corresponding catalytic mechanism was analyzed based on these analytical results. As a result, Fe²⁺ is the main active site, and ^·OH and SO₄^·- were the dominant active species. The increase in efficiency was attributed to the introduction of carbon to enhance the corrosion of mZVI further releasing more Fe²⁺. Additionally proposed were the potential response mechanism, the degradation path, and the toxicity change rule. These results demonstrate that the catalytic breakdown of antibiotics in wastewater treatment can be accelerated by the use of the outstanding catalytic material mZVI@C-800.

Keywords: Hydroxyl radical; Metronidazole; Sulfate radical; Sulfite; Zero-valent iron.