Promoted elimination of metronidazole in ferrous ions activated peroxydisulfate process by gallic acid complexation

Shoufeng Tang; Eryu Zhu; Zhihui Zhai; Huilin Liu; Zhibing Wang; Tifeng Jiao; Qingrui Zhang; Deling Yuan

doi:10.1016/j.chemosphere.2023.138025

Promoted elimination of metronidazole in ferrous ions activated peroxydisulfate process by gallic acid complexation

Chemosphere. 2023 Apr:319:138025. doi: 10.1016/j.chemosphere.2023.138025. Epub 2023 Jan 31.

Authors

Shoufeng Tang¹, Eryu Zhu¹, Zhihui Zhai¹, Huilin Liu¹, Zhibing Wang², Tifeng Jiao³, Qingrui Zhang¹, Deling Yuan⁴

Affiliations

¹ State Key Laboratory of Metastable Materials Science and Technology, Hebei Key Laboratory of Heavy Metal Deep-Remediation in Water and Resource Reuse, School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, 066004, PR China.
² State Key Laboratory of Metastable Materials Science and Technology, Hebei Key Laboratory of Heavy Metal Deep-Remediation in Water and Resource Reuse, School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, 066004, PR China. Electronic address: wzb@ysu.edu.cn.
³ State Key Laboratory of Metastable Materials Science and Technology, Hebei Key Laboratory of Heavy Metal Deep-Remediation in Water and Resource Reuse, School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, 066004, PR China. Electronic address: Jiaotf@ysu.edu.cn.
⁴ State Key Laboratory of Metastable Materials Science and Technology, Hebei Key Laboratory of Heavy Metal Deep-Remediation in Water and Resource Reuse, School of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao, 066004, PR China. Electronic address: yuandl@ysu.edu.cn.

PMID: 36736474
DOI: 10.1016/j.chemosphere.2023.138025

Abstract

We applied gallic acid (GA) as the complexing agent to stabilizing the regeneration of Fe²⁺ during the Fe²⁺/peroxydisulfate (PDS) Fenton-like reaction for promoting the removal of metronidazole (MTZ). This research evaluated the elimination of MTZ by optimizing the dose of GA and Fe²⁺ and pH condition. MTZ removal reached 83% at the GA: Fe²⁺ molar ratio of 1:1 (30 μM) and initial pH 5 and 6.2 after 120 min, and the kinetics showed two degradation phases (k_obs1 = 0.09636 for the rapid stage and k_obs2 = 0.01056 for the slow stage). The Fe²⁺ and GA complexes could expand the range of pH applicability and effectively stabilize the regeneration of Fe²⁺, which ultimately promoted the decontamination of MTZ. Sulfate radical (SO₄^.-), hydroxyl radicals, and singlet oxygen were proved to exist in this ternary system and contribute to MTZ removal, and SO₄^.- played the dominant role. Furthermore, the possible pathways and mechanisms for MTZ degradation were proposed, and the simulation result indicated that the toxicity of degradation intermediates of MTZ were declined. The GA assisted Fe²⁺/PDS system provided an improved promising advanced oxidation process for organic wastewater disposal.

Keywords: Complexing agent; Fe(2+) reduction; Metronidazole removal; Sulfate radical.

MeSH terms

Hydroxyl Radical
Iron
Metronidazole* / chemistry
Oxidation-Reduction
Water Pollutants, Chemical* / analysis

Substances

Metronidazole
Water Pollutants, Chemical
Iron
Hydroxyl Radical