Thallium adsorption onto polyacryamide–aluminosilicate composites: A Tl isotope tracer study
Adsorptive features of the composites of polyacrylamide (PAAm) and bentonite (B), and zeolite (Z) were investigated for Tl + and Tl 3+. Langmuir monolayer adsorption capacities for the corresponding ions were 1.85 and 0.97 mol kg −1 for PAAm–Z and 0.36 and 0.16 mol kg −1 for PAAm–B. The values of en...
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Published in | Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 162; no. 1; pp. 97 - 105 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Oxford
Elsevier B.V
01.08.2010
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | Adsorptive features of the composites of polyacrylamide (PAAm) and bentonite (B), and zeolite (Z) were investigated for Tl
+ and Tl
3+.
Langmuir monolayer adsorption capacities for the corresponding ions were 1.85 and 0.97
mol
kg
−1 for PAAm–Z and 0.36 and 0.16
mol
kg
−1 for PAAm–B. The values of enthalpy and entropy changes were positive for both composites and ions. The compatibility of the second order adsorption kinetics implied that the rate-controlling step was concentration dependent; the sorption process was ion exchange. High adsorption rate was found for both composites; the time required for adsorption of half of Tl
+ concentrations was 7
min.
In the presence of both ions, PAAm–B was more selective for Tl
3+ than PAAm–Z. The reusability tests for Tl
+ for five uses proved that the composites were reusable after complete recovery of the loaded ion. The values of Tl
+ adsorption onto PAAm–Z from solutions containing Fe
3+, Pb
2+, Zn
2+ confirmed that the effect of the presence of these ions on Tl
+ extraction was not significant. Although Tl
+ sorption decreased with increasing ionic strength (CaCl
2) of the medium, the results of adsorption from sea water containing 5
×
10
−6
mol
L
−1 (1
mg
L
−1) of Tl
+ ascertained that the composites still adsorbed about 10% of Tl. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 1385-8947 1873-3212 |
DOI: | 10.1016/j.cej.2010.05.005 |