Selective uptake of cesium by ammonium molybdophosphate (AMP)-calcium alginate composites

Hitoshi Mimura, Mikio Saito, Kenichi Akiba, Yoshio Onodera

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53 Citations (Scopus)


The uptake properties of Cs+ for ammonium molybdophosphate (AMP, (NH4)3PMo12O40.3H2O) and its composite with alginate gel polymer have been studied by the batch and column methods. The free energy for the ion exchange ([NH+4]ad+Cs+NH+4+[Cs+]ad) was found to have a relatively low value of -9.7 kJ/mol compared to other inorganic ion exchangers, indicating high selectivity of AMP for Cs+ ions. The fine crystals of AMP exchanger were granulated with calcium alginate (CaALG) gel polymer as an immobilization matrices. The uptake rate of Cs+ for AMP-CaALG composite was fairly fast and the uptake attained equilibrium within 3 h; the uptake was above 96% even in the presence of 5M (=mol/dm3) NaNO3. The distribution coefficient of Cs+, Kd-Cs, decreased in the order of coexisting ions, H+>Na+>K+>NH+. In a wide HNO3 concentration region of 10-2-5M, the Kd, cs value for the composite was around 104cm3/g, while those for other elements, Na+, Sr2+, Co2+, Eu3+ and Am3+, were less than 102cm3/g. The uptake of Cs+ followed a Langmuir adsorption isotherm, and the uptake capacity of Cs+ increased with the content of AMP immobilized in the composite. The trace amounts of Cs+ in the presence of HNO3 were selectively adsorbed on the composite column.

Original languageEnglish
Pages (from-to)872-878
Number of pages7
Journaljournal of nuclear science and technology
Issue number10
Publication statusPublished - 2001 Oct


  • Adsorption composite
  • Ammonium molybdophosphate
  • Breakthrough curve
  • Calcium alginates
  • Cesium
  • Distribution coefficient
  • Gel polymer
  • Immobilization
  • Langmuir adsorption isotherm
  • Uptake

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Nuclear Energy and Engineering


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