Separation of Minor Actinides and Lanthanides from High-Level liquid Waste using CMPO-Impregnated Adsorbent

To separate trivalent minor actinides and lanthanides from high-level liquid waste (HLLW), an octyl(phenyl)-N,N-diisobutylcarbamoyl methylphosphine oxide (CMPO)-impregnated adsorbent was synthesized by impregnating microporous silica particles with the CMPO extractant.The morphology of the adsorbent was characterized via scanning electron microscopy-energy-dispersive X-ray and thermogravimetric analyses.The adsorption ability of the synthesized adsorbent for Ln(III) was constant at HNO 3 concentrations of 0.1-0.5 M, whereas the adsorption of Zr(IV), Mo(VI), and Re(VII) was affected by the HNO 3 concentration.The adsorption performance of the CMPO adsorbent for Eu(III) in the solid state was studied using particle-induced X-ray emission and X-ray photoelectron spectroscopy (XPS).The depth-profiling XPS results and slope analysis revealed the formation of a complex of Eu and CMPO with a 1:3 coordination structure.The selective stripping of the adsorbed 241 Am, 152 Eu, Zr(IV), and Mo(VI) from simulated HLLW was successfully achieved using column chromatography.