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ZrO2-functionalized magnetic mesoporous SiO2 as effective phosphate adsorbent
[Display omitted] •ZrO2-functionalized magnetic mesoporous SiO2 (ZrO2-MMS) adsorbent was prepared.•ZrO2-MMS shows markedly enhanced phosphate adsorption after ZrO2 functionalization.•Grafted Zr–OH groups on ZrO2-MMS surface were responsible for this enhancement.•Phosphate adsorption on ZrO2-MMS can...
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Published in: | Journal of colloid and interface science 2013-10, Vol.407, p.442-449 |
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Main Authors: | , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | [Display omitted]
•ZrO2-functionalized magnetic mesoporous SiO2 (ZrO2-MMS) adsorbent was prepared.•ZrO2-MMS shows markedly enhanced phosphate adsorption after ZrO2 functionalization.•Grafted Zr–OH groups on ZrO2-MMS surface were responsible for this enhancement.•Phosphate adsorption on ZrO2-MMS can be slightly increased with the ionic strength.
Phosphate pollution may cause eutrophication of the aquatic environment. In the present study, magnetic mesoporous SiO2 (denoted as MMS) and ZrO2-functionalized magnetic mesoporous SiO2 (denoted as ZrO2-MMS) were prepared and phosphate adsorption over the materials was investigated. The adsorbents were characterized by X-ray diffraction, transition electron microscopy, vibration sample magnetometer, N2 adsorption/desorption, zeta-potential measurement, and X-ray photoelectron spectroscopy. The results showed that MMS consisted of magnetite with particle sizes of 10–20nm and ordered mesoporous SiO2 with the most probable pore diameter of 2.0nm. The adsorbents could be readily separated and recovered under external magnetic field. The surface grafting of ZrO2 onto MMS led to an increase in surface zeta potential due to the formation of covalently linked ZrO2 functionality on the surface of MMS. Moreover, ZrO2 functionalization resulted in enhanced phosphate adsorption. Phosphate adsorption isotherms over the adsorbents could be well described by the Freundlich model. Phosphate adsorption kinetics followed the pseudo-second-order kinetics and the adsorption rate decreased with initial phosphate concentration. Additionally, increasing pH led to suppressed phosphate adsorption, and phosphate adsorption slightly increased with ionic strength. |
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ISSN: | 0021-9797 1095-7103 |
DOI: | 10.1016/j.jcis.2013.06.053 |