Release Time:2019-03-13  Hits:

Indexed by: Journal Article

Date of Publication: 2016-04-01

Journal: JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY

Included Journals: Scopus、EI、SCIE

Volume: 78

Issue: 1

Page Number: 110-119

ISSN: 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.