Safe and efficient degradation of metronidazole using highly dispersed β-FeOOH on palygorskite as heterogeneous Fenton-like activator of hydrogen peroxide

Tiantian Luo; Miao Wang; Xike Tian; Yulun Nie; Chao Yang; Hong-Ming Lin; Wenjun Luo; Yanxin Wang

doi:10.1016/j.chemosphere.2019.124367

Safe and efficient degradation of metronidazole using highly dispersed β-FeOOH on palygorskite as heterogeneous Fenton-like activator of hydrogen peroxide

Chemosphere. 2019 Dec:236:124367. doi: 10.1016/j.chemosphere.2019.124367. Epub 2019 Jul 14.

Authors

Tiantian Luo¹, Miao Wang¹, Xike Tian¹, Yulun Nie², Chao Yang¹, Hong-Ming Lin³, Wenjun Luo¹, Yanxin Wang⁴

Affiliations

¹ Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan, 430074, China.
² Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan, 430074, China. Electronic address: ylnie@cug.edu.cn.
³ Department Materials Engineering, Tatung University, 104 Taipei, Taiwan.
⁴ School of Environmental Studies, China University of Geosciences, Wuhan, 430074, China.

PMID: 31325831
DOI: 10.1016/j.chemosphere.2019.124367

Abstract

In this study, the highly dispersed β-FeOOH on palygorskite (H-β-FeOOH/PAL) was prepared and investigated as Fenton catalyst for H₂O₂ activation towards metronidazole (MTZ). Based on electron spin resonance and probe techniques, hydroxyl radicles (^•OH) as main reactive oxygen species was confirmed, and much more ^•OH were generated over H-β-FeOOH/PAL than T-β-FeOOH/PAL using traditional impregnation method. The enhanced Fe(III) to Fe(II) cycle due to the highly dispersed β-FeOOH leads to the fast degradation of metronidazole over H-β-FeOOH/PAL. 92.8% of MTZ degradation efficiency was achieved within 180 min by adding 17 mmol/L H₂O₂ and 40 mg/L of H-β-FeOOH/PAL at pH 6.0. The bacterial cytotoxicity during MTZ degradation process also decreased with reaction time and achieved zero at 66 min, indicating MTZ was not only efficiently degraded but also safely transformed. Besides, the possible MTZ degradation pathway was further proposed based on the intermediates identified by HPLC-MS.

Keywords: Dispersed β-FeOOH; Heterogeneous Fenton-like process; Metronidazole; Performance; Reaction mechanism.

MeSH terms

Ferric Compounds / chemistry*
Hydrogen Peroxide / chemistry*
Metronidazole / pharmacology
Metronidazole / therapeutic use*

Substances

Ferric Compounds
akaganeite
Metronidazole
Hydrogen Peroxide