Separation of strontium and yttrium in nitric acid solutions using zirconium titanium phosphate and Dowex exchangers

Kilo-scale synthesis and purification of 4,4′-[di-t-butyldibenzo]-18-crown-6 and its catalytic reduction to 4,4′-[di-t-butyldicyclohexano]-18-crown-6

This article reports the large scale synthesis, scale up chromatographic purification and Rh catalyzed hydrogenation of DTBDB18C6. Confirmation of molecular structure was done by SCXRD and complete hydrogenation was achieved with the use of K+ ions.

Sorbent extraction behavior of cesium and strontium from nitric acid solutions using a new high thermal stability material

In this study a new low-cost carbonaceous material was prepared from husks of opuntia-ficus-indica as a starting material (precursor) which was accomplished by chemical activation route using H₃PO₄ impregnation. The material has been identified by different analytical tools. The sorption performance of Cs(I) and Sr(II) from HNO₃ solutions was examined through batch system. Variations of the distribution coefficients (K_d) as a function of HNO₃ concentration in the range 0.001-5.0 M were presented. Some of separation probabilities were suggested. The results attained signals that the Sr(II) selectivity is higher than that of Cs(I) at high molarities. The retention capacity (q_e) of Cs(I) and Sr(II) ions increased with growing temperature. The capacities at 0.001 M HNO₃ are 34 and 108 mg/g for Cs(I) and Sr(II), respectively. Whereas, at 2.0 M HNO₃ capacities were about 4 and 37 mg/g for each of Cs(I) and Sr (II), respectively. This studies demonstrates that the prepared carbonaceous sorbent is an economically effective sorbent for retention of Cs(I) and Sr(II) species from HNO₃ solutions. Cs(I) and Sr(II) removal potential was tested from simulated low- and intermediate-level radioactive waste samples.

Removal of strontium radionuclides from liquid scintillation waste and environmental water samples

Strontium-90 (t_1/2 = 29 y) is one of the most concerned isotopes in both nuclear accidents and reprocessing of nuclear fuel. In this study, the removal of strontium using low cost and valuable Dowex-HCR-S/S (DHS) resin was achieved. The kinetic and equilibrium sorption studies have been investigated using batch technique. The results of kinetic studies showed that the pseudo-second-order kinetic model was found to correlate well with the experimental data. Equilibrium data were also analyzed by sorption isotherm models indicating that the monolayer capacity of Sr(II) at equilibrium is 400.0 mg/g. It was concluded that resin has an efficient sorption capacity compared to many sorbents. The thermodynamic parameters of the removal (ΔH^o, ΔS^o, and ΔG^o) were also determined. The removal process was endothermic and spontaneous. The resin has been successfully applied for the removal of ⁸⁵Sr from organic liquid scintillator waste and some environmental waters such as tap water, river water, sea water and ground water samples. The present work concludes that the low-cost and commercial DHS resin used under these conditions has a major possibility as an efficacious material for the removal of ⁹⁰Sr from environmental and real radioactive wastewaters. It can therefore have a site in the treatment of radioactive liquid waste because it is of an affordable and commercially available retention material.