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  • 1 University of Cyprus P.O. Box 20537 1678 Nicosia Cyprus
  • | 2 Forschungszentrum Karlsruhe Institut für Nakleare Entsorgung P.O.Box 3640 76021 Karlsruhe Germany
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The complexation of the uranyl ion with humic acid is investigated. The humic acid ligand concentration is described as the concentration of reactive humic acid molecules based on the number of humic acid molecules, taking protonation of functional groups into account. Excess amounts of U(VI) are used and the concentration of the humic acid complex is determined by the solubility enhancement over the solid phase. pH is varied between 7.5 to 7.9 in 0.1M NaClO4 under normal atmosphere and room temperature. The solubility of U(VI) in absence of humic acid is determined over amorphous solid phase between pH 4.45 and 8.62. With humic acid, only a limited range of data can be used for the determination of the complexation constant because of flocculation or sorption of the humic acid upon progressive complexation. Analysis of the complex formation dependency with pH shows that the dominant uranyl species in the concerned pH range are UO2(OH)+ and (UO2)3(OH)5+. The complexation constant is evaluated for the humate interaction with the to UO2(OH)+ ion. The stability constant is found to be logβ = 6.94±0.3 l/mol. The humate complexation constant of the uranyl mono-hydroxo species thus is significantly higher than that of the nonhydrolyzed uranyl ion (6.2 l/mol). Published data on the Cm3+, CmOH2+ and Cm(OH)2+ humate complexation are reevaluated by the present approach. The higher stability of the hydrolysis complex is also found for Cm(III) humate complexation.

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  • Impact Factor (2019): 1.137
  • Scimago Journal Rank (2019): 0.360
  • SJR Hirsch-Index (2019): 65
  • SJR Quartile Score (2019): Q3 Analytical Chemistry
  • SJR Quartile Score (2019): Q3 Health, Toxicology and Mutagenesis
  • SJR Quartile Score (2019): Q2 Nuclear Energy and Engineering
  • SJR Quartile Score (2019): Q3 Pollution
  • SJR Quartile Score (2019): Q3 Public Health, Environmental and Occupational Health
  • SJR Quartile Score (2019): Q3 Radiology, Nuclear Medicine and Imaging
  • SJR Quartile Score (2019): Q3 Spectroscopy
  • Impact Factor (2018): 1.186
  • Scimago Journal Rank (2018): 0.408
  • SJR Hirsch-Index (2018): 60
  • SJR Quartile Score (2018): Q2 Nuclear Energy and Engineering
  • SJR Quartile Score (2018): Q2 Pollution

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Journal of Radionalytical and Nuclear Chemistry
Language English
Size A4
Year of
per Year
per Year
Founder Akadémiai Kiadó
H-1117 Budapest, Hungary 1516 Budapest, PO Box 245.
Publisher Akadémiai Kiadó
Springer Nature Switzerland AG
H-1117 Budapest, Hungary 1516 Budapest, PO Box 245.
CH-6330 Cham, Switzerland Gewerbestrasse 11.
Chief Executive Officer, Akadémiai Kiadó
ISSN 0236-5731 (Print)
ISSN 1588-2780 (Online)