Volume 108, Issue 4

The extraction of U(VI) from aqueous nitric acid solutions with pillar[5]arene-based phosphine oxide (L) and [C8mim][NTf 2 ] ionic liquid dissolved in 1,2-dichloroethane was explored. A great positive impact in this system was observed. The effect of IL concentration in the organic phase and HNO 3 concentration in the aqueous phase is considered. The distribution ratios of U(VI) were significantly enhanced upon adding a small amount of ionic liquid as compared with organic diluent. The extraction system was also examined for its ability towards extraction of lanthanides and Th 4+ . The results revealed higher separation factors towards UO 2 2+ over Th 4+ in the presence of ionic liquid compared with organic diluent. Other factors such as C 8 mim + and NTf 2 − have also been considered. This extraction system has shorter equilibrium time as compared with in IL diluent. Stripping experiments showed almost quantitative back extraction of UO 2 2+ within two stages. With high selectivity towards UO 2 2+ and efficient back extraction, this new POP5A-ionic liquid-organic diluent system shows promise for future application of uranium recovery.

Nine new templated uranyl sulfates and selenates, [(H 9 O 4 ) 2 (H 2 O)][(UO 2 ) 2 (SO 4 ) 3 (H 2 O) 2 ] ( H9US ), [(C 5 H 7 NO) 2 (H 2 O)][(UO 2 ) 2 (SeO 4 ) 3 (H 2 O) 2 ](H 2 O) ( OUSe ), [C 6 H 6 N 3 ][H 5 O 2 ] [(UO 2 ) 2 (SeO 4 ) 3 (H 2 O)] ( BH5USe ), [C 6 H 6 N 3 ][H 7 O 3 ][(UO 2 ) 2 (SO 4 ) 3 (H 2 O)](H 2 O) ( BH7US ), [C 6 H 16 N][H 5 O 2 ][(UO 2 ) 2 (SeO 4 ) 3 (H 2 O)] ( TeH5USe ), [C 6 H 18 N 2 ][(UO 2 ) 2 (SO 4 ) 3 (H 2 O)] ( TmUS ), [H 5 O 2 ] 2 [(UO 2 ) 2 (SeO 4 ) 3 (H 2 O)](H 2 O) ( H5USe-1 ), [H 5 O 2 ] 2 [(UO 2 ) 2 (SeO 4 ) 3 (H 2 O) 2 ](H 2 O) 9 ( H5USe-2 ), and [C 4 H 14 N 2 ][(UO 2 ) 2 (SeO 4 ) 3 (H 2 O)](H 2 O) ( DmUSe ) have been prepared by isothermal evaporation of aqueous solutions containing extra sulfuric or selenic acid. Their crystal structures can be considered as organo-inorganic hybrids constructed of alternating [(UO 2 ) 2 ( T O 4 ) 3 (H 2 O) n ] 2− slabs ( T  = Se 6+ , S 6+ , n  = 1, 2) and layers containing templating organic moieties and/or hydronium ions and water molecules. The organic and inorganic parts of the structures are linked by multiple hydrogen bonds. Besides structure description, we offer topological analysis of the inorganic fragments with UO 2 : T O 4 ratio of 2:3 as modular units resulting from self-assembly of fundamental chains formed by [(UO 2 ) 2 ( T O 4 ) 2 ] tetramers and T O 4 tetrahedra.

The present work provides a thorough description of the preparation of two cellulose anion exchange resins. In addition, the application of the prepared resins for treatment the uranium-contaminated wastewater. In the preparation, the first resin was cellulose reacted with 0.3 M HNO 3 to produce Activated Cellulose (AC), while the second was AC treated with sodium metasilicate and phosphoric acid to yield Silica Grafted Cellulose (SGC). The efficiency of the two prepared resins for uranium adsorption from aqueous solution was testifying on a batch scale. In solutions of pH ranging from 4 to 7, results showed a high exchange rate and uptaking capacity up to 105 mg/g. However, the addition of NO 3 − , Fe 3+ and Th 4+ ions to the target media has an adverse impact on the uranium sorption for AC adsorbent. Otherwise, the addition of uranyl sulfate complexes could ameliorate Fe 3+ and Th 4+ adsorbed into the SGC.

A novel biosorbent, i. e. Saccharomyces cerevisiae entrapped in graphene oxide (GO), polyvinyl alcohol (PVA) and alginate and cross-linked in CaCl 2 - boric acid solution, was prepared, characterized and applied for U (VI) biosorption. The performance of U sorption and cations release (Na, K, Ca and Mg ions) was investigated under different contact time, initial uranium concentration and initial pH. Uranium sorption equilibrium basically achieved after 360 min. The kinetic data of U biosorption and Ca release were best described by the pseudo first-order equation. Both Langmuir and Freundlich models could fit the U sorption isotherm data. With increase of initial uranium (3.7 ~ 472.2 μmol/L) and sodium concentration (78.8 ~ 3911.7 μmol/L), the cations release ((Na + K)/2 + (Ca + Mg)) decreased from 116.9 to 30.1 μmol/g when the corresponding U sorption increased from 0.6 to 77.3 μmol/g. Initial solution pH at 3 was favorable for U sorption when pH ranged from 3 to 7. With increase of uranium concentration, ion exchange played a less role in U removal. The maximum U sorption capacity reached 142.1 μmol/g, calculated from the Langmuir model at initial pH 5. The O-containing functional group, such as carboxyl on the gel bead played an important role in U adsorption according to FTIR and XPS analysis. XPS analysis showed the existence of U (VI) and U (IV) on the surface of gel bead. Ion exchange, complexation and uranium reduction involved in uranium adsorption by the immobilized active dry yeast gel beads.

The sorption behaviour of cesium on Tamusu clay was first investigated by batch experiments under synthetic groundwater and deionized water conditions. The results showed that the sorption could be well described by the pseud-second-order kinetic model or by the Freundlich isotherm model, and the K d values decreased rapidly when temperature was greater than 328 K. However, the influence of initial cesium concentration, initial pH and Humic acid (HA) on the sorption behaviour in the synthetic groundwater exhibited a significant difference from those in the deionized water. In particular, the K d value in the synthetic groundwater (5.47 mL/g) was much lower than that in the deionized water (58.97 mL/g). The SEM/EDS, effect of ion strength and pH-independent results in the synthetic groundwater indicated the cesium sorption on Tamusu clay was mainly involved in an ion exchange process. Additionally, the research reported in this work implies that the retardation of cesium on Tamusu clay was significantly lower than that on other clay rock in the world. The results suggest that the sorption behaviour of cesium or other nuclides on Tamusu clay should be evaluated in synthetic or actual groundwater but not in deionized water.

Liquid Scintillation Counting (LSC) is the most commonly used technique for quantification of 14 C in the environmental samples. An optimization study was carried out for the analysis of 14 C with the direct carbon dioxide absorption method using LSC. The absorption capacity of CO 2 in varying amounts of CO 2 absorber Carbo-Sorb E to Permafluor scintillation cocktail volumes is found to be 5.33 ± 0.053 mmol/mL of Carbo-Sorb E. The optimum volume ratio of Carbo-Sorb E to Permafluor scintillation cocktail is found to be 1:1 based on the minimum detection activity (MDA) values. The effect of CO 2 loading in the optimized absorption mixture shows that with an increasing CO 2 amount (up to saturation) there is an increase in tSIE values which is due to an increase of Compton scattering effect in the CO 2 loaded samples. The region of interest (ROI) for 14 C measurement is found to be 10–96 keV based on the figure of merit values and the efficiency for detecting 14 C is 83.45 % in the optimized ROI window.

To assess the suitability of 99m Tc labeled 5 α -reductase (5α-Rds) inhibitors for non-invasive targeting of prostate cancer (PCa) using Male Sprague Dawely Rat (MSDR) model. In this work, dutasteride (Cpd- 1 ) a 5α-Rds inhibitor was derivatized to its dithiocarbamate analogue (Cpd- 2 ) for subsequent synthesis of 99m Tc(CO) 3 -dutasteride dithiocarbamate (Cpd- 3 ) using tricarbonyl technique. To determine the structure of Cpd- 3 , for the first time a reference Re(CO) 3 -dutasteride dithiocarbamate (Cpd- 4 ) was synthesized and characterized with NMR, ESIMS, HPLC and elemental analysis. HPLC was used to establish the identity of Cpd- 3 using Cpd- 4 as a reference standard. The suitability of Cpd- 3 as a new 5 α -Rds targeting agent was investigated, both in vitro and vivo . The Cpd- 3 has shown ≥98 % in vitro stability at room temperature and was remained ≥90 % stable up to 6 h. In serum Cpd- 3 has revealed an analogous behavior with a small decrease in stability after 16 h. High uptake (26.25 ± 1.10 %, after 4 h of i.v.) of Cpd- 3 was observed in the prostate (target tissue) of MSDR model with reasonably good target to non-target ratio. Blocking the target site with excess Cpd- 2 considerably decreased the uptake of Cpd- 3 to 4.10 ± 0.75 % in PCa. High in vitro stability in saline and serum and in vivo uptake in prostate of MSDR model plausibly attracts the opportunity of using Cpd- 3 as a novel radiopharmaceutical for non invasive targeting of prostate.

In this research, the influence of γ-irradiation on the optical and structural properties of magnesium oxide (MgO) nanoparticles was studied. The MgO nanoparticles were irradiated with doses 100 Gy, 1 kGy, 10 kGy and 20 kGy from 60 Co source. The as-synthesized samples of MgO nanoparticles prepared by the sol-gel technique were analyzed by XRD which suggested the double phase; cubic and hexagonal structures of the material. The crystal defects that produced in the cubic and hexagonal lattice were studied before and after 60 Co γ-irradiation in a gamma cell by different dose rates in order to report the changes in structural properties of the MgO nanoparticles. The irradiated and un-irradiated samples were characterized by XRD and UV–Vis. The XRD pattern of MgO nanoparticles is showed that the crystal size of MgO nanoparticles being increased with increasing the γ-ray dose rate. For optical absorption, the UV–Visible absorption spectra of MgO nanoparticles are showed that when the dose rate is increased, the value of band gap is decreased. Also, the experimental values of the mass attenuation coefficient of MgO nanoparticles have been calculated before and after γ-irradiation by using the gamma spectroscopy method. Therefore, the results are showed that γ-ray irradiation has various effects on structural, morphological and optical properties.

Electron paramagnetic resonance spectroscopy (EPR) has been used to assess the free radical signal in different kinds of milk powder. Buffalos, colostrum’s, butter, milk cows, goat, camel and commercial milk before and after γ-ray irradiation. Moreover, un-irradiated milk samples exhibited weak signals, but upon increasing the absorbed doses EPR signal intensities were increased. The useful dose range was from 0.1 to 11 kGy. The results show that the stability of the signal of milk powder in relation to gamma irradiation was in order as follows: buffalo’s buttermilk; camel; cows; commercial milk; goat; buffalo’s; and colostrum milk. This study was recommended to use EPR as a new technique in an evaluation, quality control of dairy products and food irradiation applications. These milk powders undergo the influence of γ-rays can be applied as radiation dosimeters. Moreover, it can be used in food preservation, food irradiation processing, medical sterilization and water treating.