1. Amorphous cobalt oxide decorated halloysite nanotubes for efficient sulfamethoxazole degradation activated by peroxymonosulfate.
- Author
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He, Zhuang, Wang, Huaisheng, Li, Meng, Feng, Ligang, Niu, Jianrui, Li, Zaixing, Jia, Xiuxiu, and Hu, Guangzhi
- Subjects
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COBALT oxides , *PEROXYMONOSULFATE , *SULFAMETHOXAZOLE , *INDUCTIVELY coupled plasma atomic emission spectrometry , *HALLOYSITE , *X-ray photoelectron spectroscopy , *LIQUID chromatography-mass spectrometry - Abstract
The unique hollow nanotube structure of 30% Co-CHNTs can efficiently degrade sulfamethoxazole antibiotics. [Display omitted] • The catalyst is synthesized by the impregnation-chemical reduction-calcination method. • The degradation rate of the catalyst to sulfamethoxazole within 30 min is 97.5%. • After the catalyst is calcined, the leaching of cobalt metal ions is reduced. • The catalyst still has a good degradation rate for sulfamethoxazole in natural water. • Non-radical singlet oxygen is the main active substance in the system. In this study, a new hollow nanotube material, 30% Co–CHNTs was prepared by the impregnation–chemical reduction–calcination method. This material can be used as a peroxymonosulfate (PMS) activator to catalyse the degradation of sulfamethoxazole (SMX). The best reaction conditions that correspond to the degradation rate of SMX, up to 97.5%, are as follows: the concentration of SMX is 10 mg L−1, the amount of catalyst is 0.20 g L−1, the dosage is 1.625 mM, and the solution pH is 6.00. X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma optical emission spectrometry (ICP-OES) show that the calcined composites mainly stimulate an increase in the content of bivalent cobalt in PMS and reduce the leaching of cobalt ions after the reaction. Additionally, the 30% Co–CHNTs + PMS reaction system exhibits a reasonable SMX degradation rate in a natural organic matter solution and excellent stability after three repeated experiments. Furthermore, the possible degradation mechanism in the 30% Co–CHNTs + PMS reaction system was analysed through electron paramagnetic resonance (EPR) and free-radical capture experiments, and it was observed that the non-radical degradation of 1O 2 plays a leading role in SMX degradation. Finally, according to the nine degradation intermediates detected by liquid chromatography-mass spectrometry (LC–MS), four possible SMX degradation routes were proposed. This study proved that a 30% Co–CHNTs heterogeneous catalyst is easily prepared, inexpensive, and environmentally friendly and has potential application in antibiotic wastewater treatment. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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