Effect of adding dodecanol as modifier to N,N,N′,N′-tetra-n-hexyl-3,6-dithiaoctane-1,8-diamide silica-based adsorbent on the adsorption behaviors of platinum-group metals and other metals from simulated high-level liquid waste

To adsorb and separate platinum-group metals efficiently from simulated high-level liquid waste, two adsorbents, N,N,N′,N′-tetra-n-hexyl-3,6-dithiaoctane-1,8-diamide (THDTODA)/SiO2-P and (THDTODA + dodecanol)/SiO2-P, were prepared by impregnation of THDTODA with or without dodecanol into macroporous silica/styrene–divinylbenzene copolymer composite particles SiO2-P. The effect of the addition of dodecanol to THDTODA fixed silica-based adsorbents on the separation of platinum-group metals and other metals was evaluated by batch adsorption and chromatographic separation experiments. THDTODA/SiO2-P adsorbed Ru(III) and Rh(III) more than (THDTODA + dodecanol)/SiO2-P did in concentrated HNO3 solution. From the calculated thermodynamic parameters, dodecanol was considered to have little effect on the temperature dependence of the adsorptions of Ru(III), Zr(IV), Mo(VI), and Re(VII) onto the THDTODA adsorbents. Furthermore, in the results of column chromatography experiments, the effects of dodecanol addition on the separation properties were observed for Ru(III), Zr(IV), and Mo(VI), but little effect was observed for Pd(II) and Re(VII).

Development of MA separation process with TEHDGA/SiO2-P for an advanced reprocessing

Applicability of tetra2-ehylhexyl diglycolamide (TEHDGA) impregnated adsorbent for minor actinide (MA) recovery from high level liquid waste (HLLW) in extraction chromatography technology was investigated through batch-wise adsorption and column separation experiments. Distribution ratio of representative fission product elements were obtained by the batch-wise experiments, and TEHDGA adsorbent was shown to be preferable to TODGA adsorbent for decontamination of several species. All Ln(III) supplied into the TEHDGA adsorbent packed column was properly eluted from the column, and the applicability of the adsorbent was successfully showed by this study.