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Liang D, Hu Y, Xiao C, Wang G, Xie J, Zhu X. Highly efficient catalytic ozonation for ammonium in water upon γ-Al 2O 3@Fe/Mg with acidic-basic sites and oxygen vacancies. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 834:155278. [PMID: 35447182 DOI: 10.1016/j.scitotenv.2022.155278] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 04/10/2022] [Accepted: 04/10/2022] [Indexed: 06/14/2023]
Abstract
Catalytic ozonation has prospects in the advanced treatment of nitrogen removal, and solid base MgO can efficiently catalyze the ozonation of ammonium nitrogen. However, it is necessary to improve the problem of easy loss, difficult recovery, and low percentage of gaseous products. Here, MgO, amorphous Fe2O3, and γ-Al2O3 were selected as doping components and supports, respectively, to prepare γ-Al2O3@Fe/Mg composite catalysts with abundant acidic-basic sites and oxygen vacancies. The results show that γ-Al2O3@Fe/Mg5 can efficiently catalyze the ozonation of ammonium nitrogen (98.73%) with 67.82% gaseous product selectivity under the conditions of initial pH = 7, catalyst dosage of 112.88 g/L, and ozone dosage of 2.4 mg/min. The doping of Fe2O3 and MgO with a weaker lattice oxygen binding energy improves the gaseous product selectivity. The mechanism of ammonium nitrogen removal for γ-Al2O3@Fe/Mg5 is revealed, especially the intrinsic contribution of acidic-basic sites and oxygen vacancies. The pH and active sites play different roles in ozone decomposition for NH4+ removal. Surface hydroxyl protonation on basic sites and oxygen vacancies and electron transfer on acidic sites are responsible for ozone decomposition to hydroxyl radicals. Moreover, γ-Al2O3@Fe/Mg5 exhibits good stability, few leaching ions, and can be settled in water for easy recovery. This study suggests that γ-Al2O3@Fe/Mg5 is a good candidate for the catalytic ozonation of ammonium nitrogen.
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Affiliation(s)
- Dongmin Liang
- School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China
| | - Yongyou Hu
- School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China.
| | - Chun Xiao
- School of Environment and Energy, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China
| | - Guobin Wang
- Guangzhou Pengkai Environment Technology Co., Ltd, Guangzhou 511493, China
| | - Jieyun Xie
- Guangzhou Pengkai Environment Technology Co., Ltd, Guangzhou 511493, China
| | - Xiaoqiang Zhu
- Guangzhou Pengkai Environment Technology Co., Ltd, Guangzhou 511493, China
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