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International Journal of Environment Science and Technology
Center for Environment and Energy Research and Studies (CEERS)
ISSN: 1735-1472 EISSN: 1735-1472
Vol. 13, No. 1, 2016, pp. 113-124
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Bioline Code: st16011
Full paper language: English
Document type: Research Article
Document available free of charge
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International Journal of Environment Science and Technology, Vol. 13, No. 1, 2016, pp. 113-124
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Preparation of amino functionalized imidazolium-modified silicas by different coupling agents for removal of 2,4-dinitrophenol from aqueous solutions
Wang, Z.; Ye, C. & Wang, H.
Abstract
Amino group exhibits alkaline properties.
Amino functionalized imidazole-modified silicas would
benefit the adsorption of phenolic compounds. Coupling
agent between the silica and the imidazolium ring has an
effect on adsorption performance. In this paper, two adsorbents
were synthesized for the surface bonding of N-(3-
aminopropyl)-imidazole onto silicas modified by
3-chloropropyltriethoxysilane and 3-mercaptopropyltrimethoxysilane,
respectively. Infrared spectra, elemental
analysis, thermogravimetric analysis and N2 adsorption–desorption isotherms were used to characterize the two
adsorbents, and their adsorption capacities of 2,4-dinitrophenol
from aqueous solutions were investigated in detail.
The experimental results indicated that amino group plays
an important role in the enhancement of adsorption capacities
of 2,4-dinitrophenol. The adsorbent with 3-mercaptopropyltrimethoxysilane
as coupling agent exhibited
lower adsorption capacity due to a weak electron–electron
repulsion between the non-bonding electrons of sulfur atom
and π electrons of benzene ring of 2,4-dinitrophenol. The
adsorption kinetics fitted well with pseudo-second-order
model. The two adsorbents could be regenerated and
reused eight times at least by washing with HCl. The adsorption
mechanism was also discussed.
Keywords
Adsorption; Desorption; Ionic liquids; Silica
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