Degradation of 4-chlorophenol using MnOOH and γ-MnOOH nanomaterials as porous catalyst: Performance, synergistic mechanism, and effect of co-existing anions

Sobhan Ghanbari; Ali Fatehizadeh; Ensiyeh Taheri; Mehdi Khiadani; Hafiz M N Iqbal

doi:10.1016/j.envres.2022.114316

Degradation of 4-chlorophenol using MnOOH and γ-MnOOH nanomaterials as porous catalyst: Performance, synergistic mechanism, and effect of co-existing anions

Environ Res. 2022 Dec;215(Pt 2):114316. doi: 10.1016/j.envres.2022.114316. Epub 2022 Sep 15.

Authors

Sobhan Ghanbari¹, Ali Fatehizadeh², Ensiyeh Taheri³, Mehdi Khiadani⁴, Hafiz M N Iqbal⁵

Affiliations

¹ Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran; Student Research Committee, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran.
² Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran; Environment Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran.
³ Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran; Environment Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran. Electronic address: E_taheri@hlth.mui.ac.ir.
⁴ School of Engineering, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027, Australia. Electronic address: m.khiadani@ecu.edu.au.
⁵ Tecnologico de Monterrey, School of Engineering and Sciences, Monterrey, 64849, Mexico. Electronic address: hafiz.iqbal@tec.mx.

PMID: 36116494
DOI: 10.1016/j.envres.2022.114316

Abstract

Transition metal catalysts have been proven to be a highly-potent catalyst for peroxymonosulfate (PMS) activation. The present work aimed to synthesizes the γ-MnOOH and MnOOH based on the one-pot hydrothermal method as PMS activators for efficient degradation of 4-chlorophenol (4-CP). The effect of operational parameters including solution pH, γ-MnOOH and MnOOH dose, PMS dose, 4-CP concentration, and also mixture media composition was elaborated. The results showed that the combination of MnOOH and γ-MnOOH with PMS noticeably creates a synergistic effect (SF) in 4-CP degradation by both PMS/MnOOH and PMS/γ-MnOOH process, with a SF value of 48.14 and 97.42, respectively. In both systems, the removal of 4-CP decreased in severely alkaline and acidic conditions, while no significant changes were observed in pH 5 to 9. Also, coexisting PO₄³- significantly reduced the removal efficiency of both systems. In addition, the effect of humic acid (HA) as a classical scavenger was investigated and showed that presence of 4 mg/L HA reduced the removal efficiency of 4-CP in the PMS/MnOOH process from 97.44% to 79.3%. The three consecutive use of both catalysts turned out that MnOOH has better stability than γ-MnOOH with lower Mn ions leaching. More importantly, quenching experiment showed that both non-radical (¹O₂ and O₂^-) and radical (SO₄^- and OH) pathways are involved in 4-CP degradation and non-radical pathway was the dominant one in both systems.

Keywords: 4-Chlorophenol; Oxidation process; Peroxymonosulfate; Porous catalyst; γ-MnOOH.

Publication types

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

MeSH terms

Chlorophenols
Humic Substances*
Manganese Compounds
Nanostructures*
Oxidation-Reduction
Peroxides / chemistry
Porosity

Substances

Chlorophenols
Humic Substances
Manganese Compounds
Peroxides
manganite
peroxymonosulfate
4-chlorophenol