The radical and non-radical oxidation mechanism of electrochemically activated persulfate process on different cathodes in divided and undivided cell

Jingju Cai; Minghua Zhou; Qizhan Zhang; Yusi Tian; Ge Song

doi:10.1016/j.jhazmat.2021.125804

The radical and non-radical oxidation mechanism of electrochemically activated persulfate process on different cathodes in divided and undivided cell

J Hazard Mater. 2021 Aug 15:416:125804. doi: 10.1016/j.jhazmat.2021.125804. Epub 2021 Apr 6.

Authors

Jingju Cai¹, Minghua Zhou², Qizhan Zhang¹, Yusi Tian¹, Ge Song¹

Affiliations

¹ Key Laboratory of Pollution Process and Environmental Criteria, Ministry of Education, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Tianjin Key Laboratory of Environmental Technology for Complex Trans-Media Pollution, Nankai University, Tianjin 300350, China; Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Tianjin Advanced Water Treatment Technology International Joint Research Center, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
² Key Laboratory of Pollution Process and Environmental Criteria, Ministry of Education, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Tianjin Key Laboratory of Environmental Technology for Complex Trans-Media Pollution, Nankai University, Tianjin 300350, China; Tianjin Key Laboratory of Urban Ecology Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; Tianjin Advanced Water Treatment Technology International Joint Research Center, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China. Electronic address: zhoumh@nankai.edu.cn.

PMID: 33865104
DOI: 10.1016/j.jhazmat.2021.125804

Abstract

Electrochemically activated persulfate (PS) employing stainless steel (SS), carbon felt (CF) and carbon black modified CF (CB-CF) as the cathode, in the divided and undivided cell, respectively, for degradation of atrazine (ATZ) was first investigated using novel B, Co-doped TiO₂ nanotubes (B, Co-TNT) anode. In undivided cell, ATZ degradation was followed the order of CF<CB-CF<SS. The main radical for ATZ removal in SS and CF system was ^•OH, while on CB-CF cathode, it was the comprehensive contribution of ^•OH and SO₄^•-. ^•OH in SS system was more inclined to free ^•OH, while in CF and CB-CF systems it was more likely to be surface ^•OH. In divided anode cell, ^•OH was responsible for ATZ degradation in all three cathodes system. However, in divided cathode cell, ^•OH played a major role for ATZ degradation in SS cathode system. In CF and CB-CF cathode systems, the ATZ degradation was the comprehensive effect of ^•OH and SO₄^•- with the contribution of ^•OH and SO₄^•- was 91.7%, 8.3%, and 96.3%, 3.6%, respectively. The quenching studies showed that non-radical oxidation occurred in anode chamber in the presence of PS. Besides, the intermediates in divided and undivided cell were detected by LC-MS, and the possible degradation pathway was proposed.

Keywords: Atrazine degradation; Divided and undivided cell; Electrochemically activated PS; Radical and non-radical oxidation.

Publication types

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

MeSH terms

Atrazine* / analysis
Electrodes
Oxidation-Reduction
Water Pollutants, Chemical* / analysis

Substances

Water Pollutants, Chemical
Atrazine