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Title: Chelation Properties of Modified Humic Acids Toward Some Trivalent Lanthanide Ions

Abstract

Three kinds of humic acids, Fluka (I), Fluka (II), and Ega-chemie (III) were modified through condensation with formaldehyde to afford polymers I, II, and III, respectively. The chelation behavior of these modified humic acids polymers towards the trivalent lanthanide metal-ions, La3+, Ce3+, Nd3+, Sm3+, and Gd3+ was studied by a batch equilibration technique at 25 deg. C as a function of contact time, pH, counter ion and counter ion concentration. The highest metal-ion uptake of the three polymers was achieved at pH 7.0 and by using perchlorate as a counter ion. Results of the study have revealed that polymer II has the highest metal-ion uptake capacity, and that the metal-ion uptake falls in the order: Gd3+ > Sm3+ > Nd3+ > La3+ {approx_equal} Ce3+.

Authors:
; ;  [1]
  1. Department of Chemistry, Faculty of Science, University of Jordan, Amman, 11942 (Jordan)
Publication Date:
OSTI Identifier:
21061708
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 909; Journal Issue: 1; Conference: ICSSST 2006: 2. international conference on solid state science and technology 2006, Kuala Terengganu (Malaysia), 4-6 Sep 2006; Other Information: DOI: 10.1063/1.2739821; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CATIONS; CHELATES; FORMALDEHYDE; GADOLINIUM IONS; HUMIC ACIDS; ION-MOLECULE COLLISIONS; LANTHANUM IONS; NEODYMIUM IONS; ORGANIC POLYMERS; PERCHLORATES; PH VALUE; SAMARIUM IONS; UPTAKE

Citation Formats

Yaghmour, Remah N., Khalili, Fawwaz I., and Mubarak, Mohammad S.. Chelation Properties of Modified Humic Acids Toward Some Trivalent Lanthanide Ions. United States: N. p., 2007. Web. doi:10.1063/1.2739821.
Yaghmour, Remah N., Khalili, Fawwaz I., & Mubarak, Mohammad S.. Chelation Properties of Modified Humic Acids Toward Some Trivalent Lanthanide Ions. United States. doi:10.1063/1.2739821.
Yaghmour, Remah N., Khalili, Fawwaz I., and Mubarak, Mohammad S.. Wed . "Chelation Properties of Modified Humic Acids Toward Some Trivalent Lanthanide Ions". United States. doi:10.1063/1.2739821.
@article{osti_21061708,
title = {Chelation Properties of Modified Humic Acids Toward Some Trivalent Lanthanide Ions},
author = {Yaghmour, Remah N. and Khalili, Fawwaz I. and Mubarak, Mohammad S.},
abstractNote = {Three kinds of humic acids, Fluka (I), Fluka (II), and Ega-chemie (III) were modified through condensation with formaldehyde to afford polymers I, II, and III, respectively. The chelation behavior of these modified humic acids polymers towards the trivalent lanthanide metal-ions, La3+, Ce3+, Nd3+, Sm3+, and Gd3+ was studied by a batch equilibration technique at 25 deg. C as a function of contact time, pH, counter ion and counter ion concentration. The highest metal-ion uptake of the three polymers was achieved at pH 7.0 and by using perchlorate as a counter ion. Results of the study have revealed that polymer II has the highest metal-ion uptake capacity, and that the metal-ion uptake falls in the order: Gd3+ > Sm3+ > Nd3+ > La3+ {approx_equal} Ce3+.},
doi = {10.1063/1.2739821},
journal = {AIP Conference Proceedings},
number = 1,
volume = 909,
place = {United States},
year = {Wed May 09 00:00:00 EDT 2007},
month = {Wed May 09 00:00:00 EDT 2007}
}
  • No abstract prepared.
  • The feasibility of immobilizing radionuclides on mineral surfaces was examined in the absence and the presence of phosphate anions, using trivalent lanthanide ions (Eu3+, Gd3+, and Dy3+) as chemical analogues of trivalent actinide radionuclides. The amount of the lanthanide ions (Ln3+) sorbed on boehmite (gamma-AlOOH) surfaces dramatically increased on the presence of phosphate below pH 5. The structure of the sorbed lanthanide was determined by X-ray absorption spectroscopy, magnetic susceptibility measurements, and electron paramagnetic resonance spectroscopy. We proved Dy3+ forms precipitates on boehmite surfaces in the presence of phosphate, and Gd3+ both in the presence and absence of phosphate. Inmore » the presence of phosphate, however, these rare-earth cations react to from ultrafine particles of LnPO4 surface precipitates on boehmite surfaces.« less
  • The extraction behaviour of some tetraalkyl derivatives towards selected lanthanide ions is discussed. The effect of structure and size of the alkyl group, pH of aqueous solution and nature of counter anions (nitrate and chloride) on the extraction were investigated. High extraction efficiencies were achieved, but their separation factors were only moderately good, except for those between the smaller ions (Ho to Yb) which were good. 7 refs., 14 figs., 3 tabs.
  • TALSPEAK is a liquid/liquid extraction process designed to separate trivalent lanthanides (Ln3+) from minor actinides (MAs) Am3+ and Cm3+. Traditional TALSPEAK organic phase is comprised of a monoacidic dialkyl bis(2-ethylhexyl)phosphoric acid extractant (HDEHP) in diisopropyl benzene (DIPB). The aqueous phase contains a soluble aminopolycarboxylate diethylenetriamine-N,N,N’,N”,N”-pentaacetic acid (DTPA) in a concentrated (1.0-2.0 M) lactic acid (HL) buffer with the aqueous acidity typically adjusted to pH 3.0. TALSPEAK balances the selective complexation of the actinides by DTPA against the electrostatic attraction of the lanthanides by the HDEHP extractant to achieve the desired trivalent lanthanide/actinide group separation. Although TALSPEAK is considered a successfulmore » separations scheme, recent fundamental studies have highlighted complex chemical interactions occurring in the aqueous and organic phases during the extraction process. Previous attempts to model the system have shown thermodynamic models do not accurately predict the observed extraction trends in the p[H+] range 2.5-4.8. In this study, the aqueous phase is modified by replacing the lactic acid buffer with a variety of simple and longer-chain amino acid buffers. The results show successful trivalent lanthanide/actinide group separation with the aqueous-modified TALSPEAK process at pH 2. The amino acid buffer concentrations were reduced to 0.5 M (at pH 2) and separations were performed without any effect on phase transfer kinetics. Successful modeling of the aqueous-modified TALSPEAK process (p[H+] 1.6-3.1) using a simplified thermodynamic model and an internally consistent set of thermodynamic data is presented.« less