title: The distinct effects of Mn substitution on the reactivity of magnetite in heterogeneous Fenton reaction and Pb(II) adsorption.
abstract: In this study, a series of Mn substituted magnetites were synthesized and used in catalyzing the heterogeneous Fenton degradation of acid orange II and Pb(II) adsorption, in order to investigate the effect of Mn substitution on the reactivity of magnetite. The valence and local environment of both Fe and Mn in the spinel structure of magnetite were investigated by X-ray absorption fine structure (XAFS) spectroscopy. The incorporation of Mn did not change the valence and local structure of Fe in the synthetic magnetite, while Mn was in the valences of +2 and +3. The Mn distribution on the octahedral sites of magnetite surface increased with the increase in Mn content. The Mn introduction led to an improvement of catalytic activity of magnetite. The sample with the minimum Mn content displayed the best efficiency in OH production and the degradation of acid orange II, while the other substituted samples did not show obvious difference in their catalytic performance. The adsorption capacity of magnetite samples toward Pb(II) gradually increased with the increase in Mn content. The above influences of Mn substitution on the reactivity of magnetite were discussed in views of the variations in microstructural environment and physicochemical properties.
authors.affiliation: Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China. Electronic address: liangxl@gig.ac.cn.
authors.forename: Xiaoliang
authors.initials: X
authors.lastname: Liang
authors.affiliation: Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: hezisen881026@163.com.
authors.forename: Zisen
authors.initials: Z
authors.lastname: He
authors.affiliation: Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650, China. Electronic address: gaoling_wei@126.com.
authors.forename: Gaoling
authors.initials: G
authors.lastname: Wei
authors.affiliation: Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: liupeng@gig.ac.cn.
authors.forename: Peng
authors.initials: P
authors.lastname: Liu
authors.affiliation: Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: zhongyuanhong@gig.ac.cn.
authors.forename: Yuanhong
authors.initials: Y
authors.lastname: Zhong
authors.affiliation: Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: tanwei@gig.ac.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Tan
authors.affiliation: Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address: dupeixin@gig.ac.cn.
authors.forename: Peixin
authors.initials: P
authors.lastname: Du
authors.affiliation: Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China. Electronic address: zhujx@gig.ac.cn.
authors.forename: Jianxi
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Mineralogy and Metallogeny, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China. Electronic address: hehp@gig.ac.cn.
authors.forename: Hongping
authors.initials: H
authors.lastname: He
authors.affiliation: Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China. Electronic address: jzhang@ihep.ac.cn.
authors.forename: Jing
authors.initials: J
authors.lastname: Zhang
keywords: Adsorption; EXAFS; Heavy metal; Heterogeneous Fenton reaction; Manganese substituted magnetite