Adsorption and separation behavior of strontium and yttrium using a silica-based CMPO adsorbent

To separate Y(III) from a Sr(II)–Y(II) mixture, two silica-based adsorbents, CMPO/SiO ₂ -P and (CMPO + Dodec)/SiO ₂ -P were prepared by impregnating octyl(phenyl)-N,N-diisobutylcarbamoyl methylphosphine oxide (CMPO) extractant and a molecule modifier (1-Dodecanol) into macroporous silica/polymer composite support (SiO ₂ -P). The Adsorbents showed high adsorption affinity to Y(III) and weak adsorption affinity to Sr(II) in HNO ₃ solution. The amount of adsorbed Y(III) increased with the HNO ₃ in the solution. The amount of adsorbed Y(III) increased with contact time and reached equilibrium within 30 min. The results showed that a pseudo-second-order kinetic model with a high correlation coefficient described the adsorption process better than other kinetic models. Successful Y(III) separation from Sr(II)–Y(III) mixture in HNO ₃ solution was achieved.