Characterization of arsenate adsorption on amorphous Al gels with Keggin structure by Fourier transformed infrared spectroscopy and MAS ^(27)Al NMR

作     者：ZHAO Fenghua 

作者机构：Department of Resource and Earth Science China University of Mining and Technology Beijing 100083 China 

出 版 物：《Chinese Journal Of Geochemistry》 (中国地球化学学报)

年 卷 期：2009年第28卷第1期

页      面：61-69页

核心收录：

学科分类：070902[理学-地球化学] 0709[理学-地质学] 07[理学] 

基　　金：supported by the specialized research funds for the doctoral program of Higher Education of China (Grant No. 2006029009) the Program for New Century Excellent Talents in Universities and Colleges (Grant No. NCET-07-0801) 

主　　题：RTIR 稳定性 地球化学 元素 

摘      要：Fourier transformed infrared spectrometry (FTIR) and 27Al Magic Angle spinning (MAS) nuclear magnetic resonance spectroscopy were employed to characterize arsenate adsorption on amorphous Al gels with Keggin structure at pH =4–10. These studies have proven that: the surface complex species of arsenate show significant differences under acidic and alkaline conditions, which was deduced based on the As-O stretching vibration bands located respectively at 774 and 870 cm-1; poorly crystalline Al13 (or Al)-arsenate precipitation could be easily formed under acid medium condition and high loading level, which was supported by comparing the As-O vibration (at ≈732 cm-1) of precipitation to adsorbed Al gels; arsenate (AsO43-) adsorption has no effect on the Keggin structure of Al gels with basicity (R) =2.6 and 3.0, even at high loading level, as evidenced by the signal at ≈63×10-6 of magic angle spinning (MAS)-27Al NMR. The adsorption envelope was determined by conventional batch experiments.