Coupling Molecular-Scale Spectroscopy with Stable Isotope Analyses to Investigate the Effect of Si on the Mechanisms of Zn-Al LDH Formation on Al Oxide | |
Wenxian Gou; Wei Li; Matthew G. Siebecker; Mengqiang Zhu; Ling Li; Donald L. Sparks | |
2022 | |
发表期刊 | Environmental Science & Technology |
卷号 | 56页码:13829–13836 |
摘要 | While silicate has been known to affect metal sorption on mineral surfaces, the mechanisms remain poorly understood. We investigated the effects of silicate on Zn sorption onto Al oxide at pH 7.5 and elucidated the mechanisms using a combination of X-ray absorption fine structure (XAFS) spectroscopy, Zn stable isotope analysis, and scanning transmission electron microscopy (STEM). XAFS analysis revealed that Zn–Al layered double hydroxide (LDH) precipitates were formed in the absence of silicate or at low Si concentrations (≤0.4 mM), whereas the formation of Zn–Al LDH was inhibited at high silicate concentrations (≥0.64 mM) due to surface-induced Si oligomerization. Significant Zn isotope fractionation (Δ66Znsorbed-aqueous = 0.63 ± 0.03‰) was determined at silicate concentrations ≥0.64 mM, larger than that induced by sorption of Zn on Al oxide (0.47 ± 0.03‰) but closer to that caused by Zn bonding to the surface of Si oxides (0.60–0.94‰), suggesting a presence of Zn–Si bonding environment. STEM showed that the sorbed silicates had a close spatial coupling with γ-Al2O3, indicating that >Si–Zn inner-sphere complexes (“>” denotes surface) likely bond to the γ-Al2O3 surface to form >Al–Si–Zn ternary inner-sphere complexes. This study not only demonstrates that dissolved silicate in the natural environment plays an important role in the fate and bioavailability of Zn but also highlights the potential of coupled spectroscopic and isotopic methods in probing complex environmental processes. |
关键词 | Si Zn Co-sorption Ldh Xafs Zn Stable Isotope Stem |
DOI | 10.1021/acs.est.2c05140 |
URL | 查看原文 |
语种 | 英语 |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://ir.gyig.ac.cn/handle/42920512-1/13580 |
专题 | 环境地球化学国家重点实验室 |
作者单位 | 1.Key Laboratory of Surficial Geochemistry,Ministry of Education, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China 2.Frontiers Science Center for Critical Earth Material Cycling (FSC-CEMaC), Nanjing University, Nanjing, Jiangsu 210023, China 3.Department of Plant and Soil Science, Texas Tech University, Lubbock, Texas 79409,United State 4.Department of Ecosystem Science and Management, University of Wyoming, Laramie, Wyoming 82071, United States 5.Delaware Institute of Environment, Department of Plant and Soil Sciences, University of Delaware, Newark 19716, United States 6.State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry,Chinese Academy of Sciences, Guiyang 550081, China |
推荐引用方式 GB/T 7714 | Wenxian Gou,Wei Li,Matthew G. Siebecker,et al. Coupling Molecular-Scale Spectroscopy with Stable Isotope Analyses to Investigate the Effect of Si on the Mechanisms of Zn-Al LDH Formation on Al Oxide[J]. Environmental Science & Technology,2022,56:13829–13836. |
APA | Wenxian Gou,Wei Li,Matthew G. Siebecker,Mengqiang Zhu,Ling Li,&Donald L. Sparks.(2022).Coupling Molecular-Scale Spectroscopy with Stable Isotope Analyses to Investigate the Effect of Si on the Mechanisms of Zn-Al LDH Formation on Al Oxide.Environmental Science & Technology,56,13829–13836. |
MLA | Wenxian Gou,et al."Coupling Molecular-Scale Spectroscopy with Stable Isotope Analyses to Investigate the Effect of Si on the Mechanisms of Zn-Al LDH Formation on Al Oxide".Environmental Science & Technology 56(2022):13829–13836. |
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