Removal of aqueous uranyl ions using titania-supported mesoporous silica composite with the synergistic effect of coupled adsorption and photocatalytic reduction of U(VI)

The aim of this study is to determine and compare the adsorption capacities, kinetic and thermodynamic parameters of the adsorption process of uranyl ions from aqueous solution on nanotube titania impregnated mesoporous silica SBA-15 (TNT-SBA-15) and naked SBA-15 (nSBA-15) adsorbents. The TNT-SBA-15...

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Main Authors: Nguyen Van Chinh, Nguyen Dinh Tuyen, Dang Duc Nhan, Nguyen Lanh
Format: Article
Language:English
Published: Elsevier 2023-12-01
Series:Results in Chemistry
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2211715623003429
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author Nguyen Van Chinh
Nguyen Dinh Tuyen
Dang Duc Nhan
Nguyen Lanh
author_facet Nguyen Van Chinh
Nguyen Dinh Tuyen
Dang Duc Nhan
Nguyen Lanh
author_sort Nguyen Van Chinh
collection DOAJ
description The aim of this study is to determine and compare the adsorption capacities, kinetic and thermodynamic parameters of the adsorption process of uranyl ions from aqueous solution on nanotube titania impregnated mesoporous silica SBA-15 (TNT-SBA-15) and naked SBA-15 (nSBA-15) adsorbents. The TNT-SBA-15 composite containing various molar ratio of nanotube titania to silica (TNT-SBA-15(m:n)) in the matrix was synthesized by the sol–gel/impregnation method using sodium silicate as a silica precursor, sulphuric acid and nanotube titania. Batch adsorption experiments showed that the maximum adsorption capacity (qmax) of the TNT-SBA-15(m:n = 1:1) composite under indoor light be as high as 2.65 mMoleU g−1 that was 1.4 times higher than that of nSBA-15 under the same conditions. Under UV (300 W) illumination the qmax of TNT-SBA-15(1:1) adsorbent reached 3.49 mMoleU g−1 that was 2 times higher than the qmax in the dark. The increase in qmax of the TNT-SBA-15(1:1) composite in the two experiments was attributed to the synergistic effect of coupled sorption and photocatalytic reduction of U(VI) by titania following the deposition of uranium (IV) (hydr)oxide on the surface of the adsorbent. The adsorption process followed a pseudo-second kinetic model. The activation energy was found to be 160 and 135 kJ Mole−1 for the adsorption on nSBA-15 and TNT-SBA-15(1:1), respectively. The isotherm of the adsorption process follows the Langmuir as well as Freundlich models. The adsorption is an endothermic and spontaneous process. Adsorbed TNT-SBA-15 can be easily regenerated in 0.3 M HNO3 solution, and the qmax of the adsorbent was maintained at 95% the initial qmax after three consecutive adsorption–desorption cycles. These results revealed that, though TNT-SBA-15 made from inexpensive reagents could be an effective adsorbent for uranyl removal from wastewater.
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spelling doaj.art-8f14a55aeee6425bb290efae1d09db052023-12-10T06:15:16ZengElsevierResults in Chemistry2211-71562023-12-016101103Removal of aqueous uranyl ions using titania-supported mesoporous silica composite with the synergistic effect of coupled adsorption and photocatalytic reduction of U(VI)Nguyen Van Chinh0Nguyen Dinh Tuyen1Dang Duc Nhan2Nguyen Lanh3Institute for Technology of Radioactive and Rare Earth Elements, 48 Lang Ha, Ha Noi, Viet NamInstitute of Chemistry and Graduate University of Sciences and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, Viet NamInstitute for Nuclear Science and Technology, 179 Hoang Quoc Viet, Ha Noi, Viet Nam; Corresponding author.Institute for Technology of Radioactive and Rare Earth Elements, 48 Lang Ha, Ha Noi, Viet NamThe aim of this study is to determine and compare the adsorption capacities, kinetic and thermodynamic parameters of the adsorption process of uranyl ions from aqueous solution on nanotube titania impregnated mesoporous silica SBA-15 (TNT-SBA-15) and naked SBA-15 (nSBA-15) adsorbents. The TNT-SBA-15 composite containing various molar ratio of nanotube titania to silica (TNT-SBA-15(m:n)) in the matrix was synthesized by the sol–gel/impregnation method using sodium silicate as a silica precursor, sulphuric acid and nanotube titania. Batch adsorption experiments showed that the maximum adsorption capacity (qmax) of the TNT-SBA-15(m:n = 1:1) composite under indoor light be as high as 2.65 mMoleU g−1 that was 1.4 times higher than that of nSBA-15 under the same conditions. Under UV (300 W) illumination the qmax of TNT-SBA-15(1:1) adsorbent reached 3.49 mMoleU g−1 that was 2 times higher than the qmax in the dark. The increase in qmax of the TNT-SBA-15(1:1) composite in the two experiments was attributed to the synergistic effect of coupled sorption and photocatalytic reduction of U(VI) by titania following the deposition of uranium (IV) (hydr)oxide on the surface of the adsorbent. The adsorption process followed a pseudo-second kinetic model. The activation energy was found to be 160 and 135 kJ Mole−1 for the adsorption on nSBA-15 and TNT-SBA-15(1:1), respectively. The isotherm of the adsorption process follows the Langmuir as well as Freundlich models. The adsorption is an endothermic and spontaneous process. Adsorbed TNT-SBA-15 can be easily regenerated in 0.3 M HNO3 solution, and the qmax of the adsorbent was maintained at 95% the initial qmax after three consecutive adsorption–desorption cycles. These results revealed that, though TNT-SBA-15 made from inexpensive reagents could be an effective adsorbent for uranyl removal from wastewater.http://www.sciencedirect.com/science/article/pii/S2211715623003429AdsorptionTNT-SBA-15 adsorbentPhotocatalytic reduction, uranium(VI) removal
spellingShingle Nguyen Van Chinh
Nguyen Dinh Tuyen
Dang Duc Nhan
Nguyen Lanh
Removal of aqueous uranyl ions using titania-supported mesoporous silica composite with the synergistic effect of coupled adsorption and photocatalytic reduction of U(VI)
Results in Chemistry
Adsorption
TNT-SBA-15 adsorbent
Photocatalytic reduction, uranium(VI) removal
title Removal of aqueous uranyl ions using titania-supported mesoporous silica composite with the synergistic effect of coupled adsorption and photocatalytic reduction of U(VI)
title_full Removal of aqueous uranyl ions using titania-supported mesoporous silica composite with the synergistic effect of coupled adsorption and photocatalytic reduction of U(VI)
title_fullStr Removal of aqueous uranyl ions using titania-supported mesoporous silica composite with the synergistic effect of coupled adsorption and photocatalytic reduction of U(VI)
title_full_unstemmed Removal of aqueous uranyl ions using titania-supported mesoporous silica composite with the synergistic effect of coupled adsorption and photocatalytic reduction of U(VI)
title_short Removal of aqueous uranyl ions using titania-supported mesoporous silica composite with the synergistic effect of coupled adsorption and photocatalytic reduction of U(VI)
title_sort removal of aqueous uranyl ions using titania supported mesoporous silica composite with the synergistic effect of coupled adsorption and photocatalytic reduction of u vi
topic Adsorption
TNT-SBA-15 adsorbent
Photocatalytic reduction, uranium(VI) removal
url http://www.sciencedirect.com/science/article/pii/S2211715623003429
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