Comparative study on the removal of 1- naphthol and 2-naphthol by ferrate (VI): Kinetics, reaction mechanisms and theoretical calculations

Yumeng Qi; Yao Yu; Ahmed A Allam; Jamaan S Ajarem; Naif G Altoom; Afzal Ahmed Dar; Xiaosheng Tang; Zunyao Wang; Ruijuan Qu

doi:10.1016/j.chemosphere.2023.139189

Comparative study on the removal of 1- naphthol and 2-naphthol by ferrate (VI): Kinetics, reaction mechanisms and theoretical calculations

Chemosphere. 2023 Sep:336:139189. doi: 10.1016/j.chemosphere.2023.139189. Epub 2023 Jun 10.

Authors

Yumeng Qi¹, Yao Yu¹, Ahmed A Allam², Jamaan S Ajarem³, Naif G Altoom³, Afzal Ahmed Dar⁴, Xiaosheng Tang⁵, Zunyao Wang⁶, Ruijuan Qu¹

Affiliations

¹ State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China.
² Department of Zoology, Faculty of Science, Beni-suef University, Beni-suef, 65211, Egypt.
³ Department of Zoology, College of Science, King Saud University, P.O. Box 2455, Riyadh, 11451, Saudi Arabia.
⁴ Department of Physics, Polytechnique Montreal, C.P. 6079, Succ Centre-ville, Montreal, QC H3C 3A7, Canada.
⁵ Jiangsu Yangtze River Delta Environmental Science and Technology Research Institute Co., Ltd., Changzhou, 213100, Jiangsu, PR China.
⁶ State Key Laboratory of Pollution Control and Resources Reuse, School of the Environment, Nanjing University, Nanjing, 210023, Jiangsu, PR China. Electronic address: wangzy@nju.edu.cn.

PMID: 37307926
DOI: 10.1016/j.chemosphere.2023.139189

Abstract

In this study, the oxidation of 1-naphthol (1-NAP) and 2-naphthol (2-NAP) by Fe(VI) was investigated. The impacts of operating factors were investigated through a series of kinetic experiments, including Fe(VI) dosages, pH and coexisting ions (Ca²⁺, Mg²⁺, Cu2⁺, Fe³⁺, Cl^-, SO₄^2-, NO₃^- and CO₃^2-). Almost 100% elimination of both 1-NAP and 2-NAP could be achieved within 300 s at pH 9.0 and 25 °C. Cu²⁺ could significantly improve the degradation efficiency of 1-NAP and 2-NAP, but the impacts of other ions were negligible. The liquid chromatography-mass spectrometry was used to identify the transformation products of 1-NAP and 2-NAP in Fe(VI) system, and the degradation pathways were proposed accordingly. Electron transfer mediated polymerization reaction was the dominant transformation pathway in the elimination of NAP by Fe(VI) oxidation. After 300 s of oxidation, heptamers and hexamers were found as the final coupling products during the removal of 1-NAP and 2-NAP, respectively. Theoretical calculations demonstrated that the hydrogen abstraction and electron transfer reaction would easily occur at the hydroxyl groups of 1-NAP and 2-NAP, producing NAP phenoxy radicals for subsequent coupling reaction. Moreover, since the electron transfer reactions between Fe(VI) and NAP molecules were barrierless and could occur spontaneously, the theoretical calculation results also confirmed the priority of coupling reaction in Fe(VI) system. This work indicated that the Fe(VI) oxidation was an effective way for removing naphthol, which may help us understand the reaction mechanism between phenolic compounds with Fe(VI).

Keywords: 1-Naphthol; 2-Naphthol; DFT calculation; Ferrate; Reaction mechanism.

MeSH terms

Kinetics
Naphthols
Oxidation-Reduction
Water Pollutants, Chemical* / chemistry
Water Purification* / methods

Substances

ferrate ion
2-naphthol
1-naphthol
Naphthols
N-(2-naphthalenesulfonyl)aspartyl-(2-phenethyl)amide
Water Pollutants, Chemical