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Dai H, Xu S, Chen J, Miao X, Zhu J. Oxalate enhanced degradation of Orange II in heterogeneous UV-Fenton system catalyzed by Fe 3O 4@γ-Fe 2O 3 composite. Chemosphere 2018; 199:147-153. [PMID: 29433028 DOI: 10.1016/j.chemosphere.2018.02.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 01/31/2018] [Accepted: 02/04/2018] [Indexed: 06/08/2023]
Abstract
Oxalate enhanced mechanism of Fe3O4@γ-Fe2O3 was developed to provide novel insight into catalytic process regulation of iron oxide catalysts in heterogeneous UV-Fenton system. And the iron oxide composite of Fe3O4@γ-Fe2O3 was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), fourier transform infrared (FTIR) spectroscopy and nitrogen adsorption-desorption isotherms. The results showed that large amount of iron could be leached from catalyst in the presence of oxalate, which promoted the homogeneous UV-Fenton reactions in solution. Orange II degradation could be significantly enhanced with the increase of the ratio of homogeneous UV-Fenton process to heterogeneous UV-Fenton process. The optimum concentration of oxalate determined by experiment was 0.5 mM in oxalate enhanced heterogeneous UV-Fenton system. On this condition, the pseudo-first-order rate constant value of Orange II degradation was 0.314 min-1, which was 2.3 times as high as that in heterogeneous UV-Fenton system. The removal rates of color and TOC were 100% and 86.6% after 20 min and 120 min treatment, respectively. In addition, the iron ions in solution could be almost completely adsorbed back to the catalyst surface in later degradation stages of Orange II. During the recycle experiments, the results showed that the increase of pH in solution and the sorption of intermediates on the catalyst surface would hinder oxalate enhanced process and lead to a decrease of degradation rate of Orange II in oxalate enhanced heterogeneous UV-Fenton system.
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Affiliation(s)
- Huiwang Dai
- School of Resources, Environmental and Chemical Engineering, Nanchang University, Nanchang 330031, Jiangxi, China; The Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang 330031, Jiangxi, China.
| | - Shuying Xu
- School of Resources, Environmental and Chemical Engineering, Nanchang University, Nanchang 330031, Jiangxi, China; The Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang 330031, Jiangxi, China.
| | - Jianxin Chen
- School of Resources, Environmental and Chemical Engineering, Nanchang University, Nanchang 330031, Jiangxi, China; The Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang 330031, Jiangxi, China.
| | - Xiaozeng Miao
- School of Resources, Environmental and Chemical Engineering, Nanchang University, Nanchang 330031, Jiangxi, China; The Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang 330031, Jiangxi, China.
| | - Jianxi Zhu
- Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (CAS) Guangzhou, 510640, China; Guangdong Provincial Key Laboratory of Mineral Physics and Materials, 510460, China.
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