Structural Incorporation of Manganese into Goethite and Its Enhancement of Pb(II) Adsorption

被引：99

作者：

Liu, Huan ^{[1
,2
]}

Lu, Xiancai ^{[1
]}

Li, Meng ^{[1
]}

Zhang, Lijuan ^{[3
]}

Pan, Chao ^{[4
]}

Zhang, Rui ^{[1
]}

Li, Juan ^{[1
]}

Xiang, Wanli ^{[1
]}

机构：

[1] Nanjing Univ, Sch Earth Sci & Engn, Minist Educ, Key Lab Surficial Geochem, Nanjing 210023, Jiangsu, Peoples R China

[2] Washington Univ, Dept Earth & Planetary Sci, 1 Brookings Dr, St Louis, MO 63130 USA

[3] Chinese Acad Sci, Shanghai Inst Appl Phys, Shanghai Synchrotron Radiat Facil, Shanghai 201204, Peoples R China

[4] Washington Univ, Dept Energy Environm & Chem Engn, St Louis, MO 63130 USA

来源：

ENVIRONMENTAL SCIENCE & TECHNOLOGY | 2018年 / 52卷 / 08期

基金：

美国国家科学基金会;

关键词：

RAY-ABSORPTION SPECTROSCOPY; MN-SUBSTITUTED GOETHITE; TOTAL ELECTRON YIELD; ALPHA-FEOOH; IRON-OXIDE; SURFACE COMPLEXATION; SYNTHETIC GOETHITE; ALUMINUM SUBSTITUTION; DOPED GOETHITE; PROBING DEPTH;

D O I：

10.1021/acs.est.7b05612

中图分类号：

X [环境科学、安全科学];

学科分类号：

08 ; 0830 ;

摘要：

Natural goethite (alpha-FeOOH) commonly accommodates various metal elements by substituting for Fe, which greatly alters the surface reactivity of goethite. This study discloses the enhancement of Mn-substitution for the Pb(2+)adsorption capacity of goethite. The incorporated Mn in the synthesized goethite presents as Mn(III) and causes a slight decrease in the a and c of the unit cell parameters and an observable increase in the b direction due to the Jahn-Teller effect of the Mn(III)O-6 octahedra. With the Mn content increasing, the particle size decreases gradually, and the surface clearly becomes roughened. The Pb2+ adsorption capacity of goethite is observably enhanced by Mn substitution due to the modified surface complexes. And the increased surface-area-normalized adsorption capacity for Mn-substituted goethite indicated that the enhancement of Pb adsorption is not only attributed to the increase of surface area but also to the change of binding complexes. Extended X-ray absorption fine structure (EXAFS) analysis indicates that the binding structures of Pb2+ on goethite presents as edge-sharing complexes with a regular RPb-Fe = 3.31 angstrom. In the case of Mn-goethite, Pb2+ is also bound with the Mn surface site on the edge-sharing complex with a larger RPb-Fe = 3.47 angstrom. The mechanism for enhancing Pb2+ adsorption on Mn-goethite can be interpreted as the preferred Pb2+ binding on the Mn site of Mn-goethite surface. In a summary, the Mn-goethite has great potential for material development in environmental remediation.

引用

页码：4719 / 4727

页数：9