Composite Absorbers Consisting of Inorganic Ion-Exchangers and Polyacrylonitrile Binding Matrix: Leaching of ¹³⁷Cs from Cemented NiFC-PAN Absorber

Abstract

Results of dynamic leaching tests of ,37 Cs from caesium loaded cemented NiFC-PAN composite absorber (nickel hexacyanoferrate active component in a binding matrix of modified polyacrylonitrile) have shown that cumulative fractions leached were ~100 times lower when compared to cemented U7 Cs solution. Diffusion coefficients as low as 1.10" 16 m 2 · s"' were found for the best samples (1% of clinoptilolite). The activation energy of the leaching process was found to be as high as 130 kJ · mole" 1 .

Adsorption and thermodynamics studies of U(VI) by composite adsorbent in a batch system

“…Especially inorganic ion exchangers such as clays have been studied extensively for the application to the various waste treatments due to their selectivity for the specific ions and thermal and radiation stabilities. The application of organic ion exchange resins to the radwaste treatment has been decreased because they possibly release the radionuclides by decomposition of organic binding matrix when disposed underground [18].…”

Ion exchange of strontium and caesium ions using PAN-4A composite ion exchanger

“…For these reasons, the studies on the preparation of composite adsorbents using organic binder such as polymer have been intensively performed [7][8][9][10][11][12]. Many organic polymers have been suggested as binders in preparing composite beads.…”

“…~ebesta et al [11] proved that PAN and PAN-AMP beads are stable when irradiated up to 1 MGy. John et al [9] conducted leaching tests of 137Cs from Cs loaded cemented PAN-NiFC adsorbent and they proved that the leachability of Cs from PANNiFC beads was much lower than those from simply cemented Cs solution. Moon et al [12] prepared PAN-K2Ti409 and PAN-Ni2Fe(CN) 6 composite ion exchangers and evaluated adsorption behaviours for strontium and silver.…”