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Indexed by:期刊论文

Date of Publication:2016-04-01

Journal:JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY

Included Journals:SCIE、EI、Scopus

Volume:78

Issue:1

Page Number:110-119

ISSN No.:0928-0707

Key Words:Diatomite; Functionalized mesoporous silica; Adsorption; Cd(II)

Abstract:The ordered mesoporous silica functionalized with -NH2 groups was successfully synthesized using diatomite as silica source and used to adsorb Cd(II) ions from aqueous solution. The resultant adsorbent was characterized by X-ray powder diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption measurements, thermogravimetric analysis, the elemental analyzer and transmission electron microscopy. The effects of different concentrations of 3-aminopropyltrimethoxysilane, solution pH, adsorbent dose, contact time were thoroughly investigated. The adsorption kinetic studies were analyzed using pseudo-first-order, pseudo-second-order and intraparticle diffusion models, and the adsorption isotherms were studied by Langmuir and Freundlich isotherm models. The results showed that the adsorption process was successfully fitted with the pseudo-first-order kinetics and Langmuir isotherm models. It was found that the maximum adsorption capacity of adsorbents obtained under optimum synthesis conditions reached 102.9 mg/g at 25 A degrees C, indicating that this new sorbent could have a good potential for the removal of Cd(II) due to its low cost and eco-friendliness.