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Thermodynamics of the Eu( iii )–Mg–SO₄ –H₂O and Eu( iii )–Na–SO₄ –H₂O systems. Part I: solubility experiments and the full dissociation Pitzer model

Santos, P. F. dos 1; Lassin, A.; Gaona, X. ORCID iD icon 1; Garbev, K. ORCID iD icon 2; Altmaier, M. ORCID iD icon 1; Madé, B.
1 Institut für Nukleare Entsorgung (INE), Karlsruher Institut für Technologie (KIT)
2 Institut für Technische Chemie (ITC), Karlsruher Institut für Technologie (KIT)

Abstract:

The solubility of Eu(III) was investigated under undersaturated conditions in acidic, dilute to concentrated MgSO4 and Na2 SO4 solutions at T = (22 ± 2) °C. After attaining equilibrium conditions, solid phases were characterized by a multi-method approach, including X-ray diffraction (XRD), Raman and infrared (IR) spectroscopy, quantitative chemical analysis (ICP-OES) and thermogravimetric analysis (TG-DTA). A total of 45 solubility samples were investigated for the systems Eu2 (SO4) 3–MgSO4–H 2O (19 samples) and Eu2 (SO4) 3–Na2SO 4–H2 O (26 samples). Eu2 (SO4) 3·8H2 O(cr) was found to control the solubility of Eu(III) in all investigated MgSO4 solutions, as well as in dilute Na 2SO 4 systems. The transformation of Eu 2(SO4 ) 3·8H2 O(cr) into the double salt Na 2Eu2 (SO4) 4 ·2H2O(cr) was observed at mNa2 SO4 > 0.01 mol kg−1. The latter phase is characterized by significantly lower solubility. Based on these experimental solubility measurements, thermodynamic and activity models were proposed based on the Pitzer equations considering the full dissociation of the Eu(III) species in MgSO4 and Na2 SO4 aqueous solutions, i.e. deliberately excluding Eu(III)-sulfate complex formation. ... mehr


Verlagsausgabe §
DOI: 10.5445/IR/1000170458
Veröffentlicht am 10.05.2024
Originalveröffentlichung
DOI: 10.1039/d3dt04322c
Scopus
Zitationen: 1
Web of Science
Zitationen: 1
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Zitationen: 1
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Nukleare Entsorgung (INE)
Institut für Technische Chemie (ITC)
Publikationstyp Zeitschriftenaufsatz
Publikationsdatum 02.04.2024
Sprache Englisch
Identifikator ISSN: 1477-9226, 1477-9234
KITopen-ID: 1000170458
HGF-Programm 32.11.01 (POF IV, LK 01) Nuclear Waste Disposal
Weitere HGF-Programme 38.05.02 (POF IV, LK 01) Metals and Minerals Cycle
Erschienen in Dalton Transactions
Verlag Royal Society of Chemistry (RSC)
Band 53
Heft 14
Seiten 6289–6299
Vorab online veröffentlicht am 14.03.2024
Nachgewiesen in Dimensions
Scopus
Web of Science
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