Adsorption and separation performance of platinum group metals using a novel MPE-TDGA/SiO2 -P adsorbent

For the efficient separation of platinum group metals (PGMs) from high-level radioactive liquid waste (HLLW), a novel adsorbent, N,N' -dimethyl- N,N' -di-(2-phenylethyl)-thiodiglycolamide (MPE-TDGA) impregnated on macroporous silica–polymer composite particles (SiO₂-P), MPE-TDGA/SiO₂-P, was developed. Characterization of MPE-TDGA/SiO₂-P confirmed successful impregnation of the extractant into the SiO₂-P. In the adsorption and separation of PGMs from simulated HLLW in batch experiments, MPE-TDGA/SiO₂-P afforded nearly 100% Pd(II) adsorption efficiency; the adsorption efficiencies for Ru(III) and Rh(III) increased at higher temperatures. Ru(III), Rh(III), and Pd(II) were individually separated through a two-stage column process. MPE-TDGA/SiO₂-P is a promising adsorbent for the practical separation of PGMs from HLLW.