Inorganic ion-exchangers in radioactive waste management. Part XVI: Uptake of some metal phosphates (stannic and zirconium) for 134Cs

Abstract

The uptake of indigenously synthesized amorphous stannic and zirconium phosphate was assessed for, one of the important fission fragment, cesium from aqueous solutions using a radiotracer technique. A virtual increase in sorptive concentration (from 1.0·10-8 to 1.0·10-2 mol·dm-3) and pH (from 2.4 to 10.2) and temperature (from 303 to 333 K) enhanced the uptake of cesium on stannic phosphate. However, the extremely high degree of uptake of cesium on zirconium phosphate was almost unaffected with the dilution beyond 10-5 mol·dm-3 and pH (i.e., from 2.4 to 10.2) and temperature (from 303 to 323 K). Irreversible uptake occurring for these solids follow the Freundlich adsorption isotherm and the presence of several complexing agents viz., sulphate, phosphate, glycine and EDTA did not affect appreciably the uptake of cesium on zirconium phosphate but it did affect for stannic phosphate system. Both these solids showed good radiation stability towards a 11.1 GBq Ra-Be neutron source having neutron flux ca. 3.2·106 n·cm -2·s-1 and associated with a nominal γ-dose of ca. 1.72 Gy/h, at least for the uptake of cesium. © 2006 Akadémiai Kiadó.