Chromatographic Separations of Traces 134Cs, 60Co, and 152,154Eu Using Silico-, Molybdo-, and Chromotitanates as Inorganic Ion Exchangers

Silicotitanate, molybdotitanate, and chromotitanate as inorganic ion exchange materials were synthesized with Si/Ti, Mo/Ti, and Cr/Ti ratios equal to 1.0, 1.33, and 0.5, respectively. The chemical composition of the synthesized materials were determined and found to SiTiO4·9.52H2O, Mo4Ti3O16·10.2H2O, and Cr2Ti4O11·5.65H2O for silicotitanate, molybdotitanate, and chromotitanate, respectively. Schematic illustrations of these materials were achieved according to the related structures. The stability of these synthesized materials in different media showed high resistance toward chemical attack. Batch adsorption technique was used for the investigation of the distribution coefficients of 134Cs, 60Co, and 152,154Eu from synthetic mixture solutions on the three inorganic ion exchangers. The effect of the medium composition (pH) on the distribution coefficients was studied, and the data obtained indicated that 60Co had a very low distribution coefficient on the three ion exchangers in 0.1 M HNO3 and a mixed system of 0.1 M HNO3 + 0.1 M NaNO3. 134Cs and 152,154Eu are highly adsorbed on molybdotitanate and chromotitanate in 0.1 M HNO3 medium; on the other hand, these ions have high distribution coefficients on silicotitanate in 0.1 M HNO3 + 0.1 M NaNO3 medium. Based on the batch distribution coefficient data achieved, chromatographic column separations of 134Cs−60Co, 134Cs−152,154Eu, and 60Co−152,154Eu were carried out using different eluants such as 0.01 M HNO3, 0.1 M HNO3, 0.1 M NH4Cl, and 0.1 M NH4OH.