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1.
A method of preparation of hydrated zirconium oxide suitable for113mIn generators was elaborated. A good separation of113mIn from113Sn was obtained in the course of routine use of generator, with a very small admixture of zirconium in the eluate. 相似文献
2.
Yu. A. Grankina V. N. Shubina V. A. Elizarova V. V. Donskikh 《Russian Journal of Applied Chemistry》2016,89(1):40-44
Carbon dioxide absorber based on hydrated zirconium oxide was synthesized with ammonium carbonate and hydrogen peroxide. The effect of the molar ratio between ammonium carbonate and hydrogen peroxide on the sorption characteristics of the absorber was examined. The structural-sorption properties of the absorber were analyzed. It was shown tat the absorber has a high absorption capacity for CO2. 相似文献
3.
Highly dispersed zirconium phosphate was prepared by reacting Cel/ZrO(2) (ZrO(2)=6.7 wt%; 0.56 mmol g(-1) of zirconium atom per gram of the material) with phosphoric acid. High power decoupling magic angle spinning (HPDEC-MAS)(31)P NMR and X-ray photoelectron spectroscopy data indicated that HPO(2-)(4) is the species present on the fiber surface. The X-ray diffraction patterns showed that zirconium hydrogen phosphate particles were amorphous and had an ion-exchange capacity, determined by ammonia gas adsorption, of 0.30 mmol g(-1). The ion-exchange capacities for Li(+), Na(+), and K(+) ions were determined from ion-exchange isotherms at 298 K and showed the following values (in mmol g(-1)): Li(+)=0.01, Na(+)=0.23, and K(+)=0.30. The higher affinity of the surface hydrogen phosphate particles for Na(+) and K(+) is due to its lamelar structure which permits easier diffusion of these two ions whose hydrated radii are smaller than that of Li(+). 相似文献
4.
A. Mushtaq M. S. Mansoor H. M. A. Karim M. A. Khan 《Journal of Radioanalytical and Nuclear Chemistry》1991,147(2):257-261
The adsorption behaviour of99Mo in the form of molybdate and of99mTc in the form of pertechnetate on hydrated titanium dioxide was investigated at different molarities of hydrochloric acid. The adsorption capacity of molybdate on hydrated TiO2 is higher than on Al2O3. A99mTc-generator is suggested. This generator is based on the adsorption of (99Mo) molybdate on hydrated TiO2, at acidities of 0.05–0.1M. HCl.99mTc is eluted with 0.9% NaCl. Radionuclidic, radiochemical and chemical purities of the eluates were checked. This generator seems to have a great potential as compared to the traditional alumina generators. 相似文献
5.
Silica gel was prepared by the sol–gel method, modified with nanometer-sized zirconium oxide, and this material was characterized
by X-ray diffraction. A micro-column packed with silica gel modified with nanometer zirconium oxide as sorbent has been developed
for the quantitative separation and preconcentration of trace amounts of chromium(III) prior to their determination by electrothermal
atomic absorption spectrometry. Total chromium was determined after the reduction of chromium(VI) to chromium(III) by 10%
(m/v) of aqueous ascorbic acid as reducing reagent. The adsorption capacity for chromium(III) was found to be 2.36 mg g−1. The detection limit for chromium(III) was 15 ng L−1 with an enrichment factor of 100. The relative standard deviation was 3.2% (n = 7, c = 2.0 ng mL−1). 相似文献
6.
Barium may be determined gravimetrically in quantities ranging from 0.2 to 2.0 mg (± o.1 mg) in hydrated zirconyl chloride and in zirconium metal after complete separation of the zirconium. As much as 10 g of zirconium may be removed by a double precipitation in a (3 to 1) hydrochloric acid medium followed by a cupferron precipitation-chloroform extraction of the residual zirconium. The barium is then determined gravimetrically as barium sulfate in the iron-free, zirconium-free filtrate by precipitation with an excess of ammonium sulfate. As much as 0.015% barium has been found in impure zirconyl chloride, 0.004% in commercial “purified” zirconyl chloride, 0.000% barium in crystal bar zirconium metal and 0.003% barium in zirconium metal sheet. Reproducibility is 0.001%. 相似文献
7.
A99Mo/99mTc generator, system was made with a performed titanium molybdate gel. The irradiation was carried out at a medium neutron flux of 1.5×1013 n cm–2·s–1. The irradiated matrix was loaded on top of a column composed of hydrous zirconium oxide alumina. The elution efficiency and the amount of total technetium per mCi99mTc in the generator eluents have been determined. Molybdenum breakthrough has also been determined and compared with literature values. The influence of the particle size, water content, neutron flux and molybdenum content on the total99mTc-activity has been investigated. 相似文献
8.
Adsorption of selected ions on hydrous cerium oxide 总被引:2,自引:0,他引:2
A. Nilchi M. Yaftian G. Aboulhasanlo S. Rasouli Garmarodi 《Journal of Radioanalytical and Nuclear Chemistry》2009,279(1):65-74
Hydrous cerium oxide was synthesized and laboratory study was conducted to address its applicability for decontamination of
barium, strontium, molybdenum, europium, iodine, samarium and cesium ions from radioactive liquid wastes using radiotracer
technique. The adsorption of Ba(II), Sr(II), Mo(II), Eu(II), I(I), Sm(III) and Cs(I) on hydrous cerium oxide has been investigated
as a function of pH, concentration and temperature of the adsorptive solution and the result obtained show that these parameters
affect the extent of adsorption. The ion-exchange capacity decreased at higher temperatures which could be due to decrease
of active sites as well as hydrophilic properties of surface adsorbent. Hydrous cerium oxide shows relatively high adsorption
in acidic and neutral media towards the radiotracers studied, which can be attributed to large hydrated radius and ion exclusion
effect. 相似文献
9.
Abstract— An approach employing hydrated electron photoemission from a mercury electrode and potentiostatic chronoamperometric monitoring of the associated electrochemical processes has been applied to the study of the hydrated electron scavenging reactions of simple biological molecules. The current-voltage profiles of aqueous glutathione and triglycine solutions were measured following flash-induced photoemission. The redox properties of the products of electron scavenging were characterized by comparison to similar current-voltage measurements resulting from hydrated electron capture by nitrous oxide. The electrochemical behavior so determined was directly related to the particular scavenging process occurring with each scavenger and agreed generally with previous pulse radiolytic studies made on the same scavenging systems. 相似文献
10.
Summary Hydrous zirconium dioxide was prepared to study the sorption behavior and the removal of strontium from radioactive waste
solutions. The hydrous zirconium dioxide were identified and characterized. The parameters affecting the strontium adsorption
were investigated. Sorption data have been interpreted in terms of Langmuir equations. Thermodynamic parameters for the sorption
system have been determined at 303, 313, 323 and 333 K temperatures. The values ofDH°=102.30 kJ/mol andDG°=-26.03 kJ/mol at 313 K prove that the sorption of strontium on hydrous zirconium oxide is an endothermic and a spontaneous
process. 相似文献
11.
Selective separation behavior of silica gel for zirconium in simulated high level radioactive liquid waste 总被引:1,自引:0,他引:1
Y. Q. Zhang R. S. Wang C. Sh. Lin X. Y. Zhang 《Journal of Radioanalytical and Nuclear Chemistry》2001,247(1):205-208
Zirconium in simulated high level radioactive liquid waste (HLLW) was selectively adsorbed and separated by self-made high adsorption activity silica gel. The selective adsorption mechanism was analyzed according to the structure character of self-made silica gel and performance of zirconium in acid simulated HLLW. The results show that the adsorption selectivity of self-made silica gel for zirconium is strong, because zirconium has higher positive charge and zirconium ion hydrolyzes easily. Distribution coefficient of self-made silica gels for zirconium is 53.5 ml/g. There are 6.5 (OH)/nm2 on the surface on self-made silica gels which provide more adsorption activity places, thus self-made silica gels have higher adsorption capacity for zirconium (31.4 mg/g). The elution rate of the adsorption of zirconium on self-made silica gel by 0.2 mol/l H2C2O4 is more than 99%. The solubility of the self-made silica gel in nitric acid is low, the chemical stability of self-made silica gel is very strong. 相似文献
12.
Bellezza F Cipiciani A Costantino U Marmottini F 《Langmuir : the ACS journal of surfaces and colloids》2006,22(11):5064-5069
Porous zirconium phosphate (P-ZrP) and zirconium benzenephosphonate (P-ZrBP) were prepared in the presence of an anionic surfactant acting as a template. Poorly crystalline materials with a P/Zr molar ratio equal to 2 and having a relatively high surface area and micro/mesoporosity have been obtained. The interaction of myoglobin with the two types of surfaces, the hydrophobic P-ZrBP and the hydrophilic P-ZrP, was investigated, and the adsorption isotherms were determined at different pH and temperature values. A model was proposed for the mechanism of the interaction of the protein with the surface based on the shape of the adsorption isotherm and the physical-chemical properties of myoglobin. The pH has been found to be an important parameter for determining the maximum adsorption capacity of P-ZrBP and P-ZrP for myoglobin molecules because of the changes that occur in the type and net charge of the protein surface as the pH of the medium changes. Protein binding affinity and capacity increase when the temperature is increased. This phenomenon occurs because myoglobin varies its conformation at high temperature with an increase in the exposed hydrophobic region. This process causes a stronger hydrophobic interaction between the protein and the adsorbent and reduces the repulsion between the adsorbed molecules. Studies on the activities of the obtained biocomposites are in progress. 相似文献
13.
Amorphous zirconium phosphate ion-exchanger has been prepared in our laboratory according to the procedure given by Gal and Gal. The Chemical composition has been determined. Some chemical properties; stabilities and sorption of mono- to hexavalent cations have been studied in detail. It was found that washing the zirconium phosphate ion exchanger with alcohol before drying would increase the exchange capacity of amorphous zirconium phosphate. 相似文献
14.
Chepurna I Smotraev R Kanibolotsky V Strelko V 《Journal of colloid and interface science》2011,356(2):404-411
The processes of coagulation and gelation of sols in zirconium oxychloride aqueous solutions and the properties of hydrated zirconium dioxide sols (pH, particles size, dynamic viscosity) depending on the aging conditions of partially neutralized zirconium oxychloride feedstock solution-zirconyl hydroxychloride used for the synthesis and molar ratio of initial reagents (Zr/NaOH, Zr/CH(3)COO(-)) were first studied in the paper. The concentration and temperature limits of hydrated zirconium dioxide sols stability were determined. The coagulation constant, gelation activation energy, and gelation thermal effect values were found. 相似文献
15.
Griffith CS Sizgek GD Sizgek E Scales N Yee PJ Luca V 《Langmuir : the ACS journal of surfaces and colloids》2008,24(21):12312-12322
A series of zirconium titanium oxide mesophases containing 33 atom % Zr have been prepared using carboxylic acids of different alkyl chain lengths (Cy ) from y=4-18 through organic-inorganic polymer phase segregation as the gel transition is approached. Thermal treatment of these transparent gels up to 450 degrees C eliminated the organic template, and domain coarsening occurred affording stable worm-hole mesoporous materials of homogeneous composition and pore diameters varying from about 3 to 4 nm in fine increments. With such materials, it was subsequently possible to precisely study the adsorption of vanadium oxo-anions and cations from aqueous solutions and, more particularly, probe the kinetics of intraparticle mass transport as a function of the associated pore dimension. The kinetics of mass transport through the pore systems was investigated using aqueous vanadyl (VO2+) and orthovanadate (VO3(OH)2-) probe species at concentrations ranging from 10 to 200 ppm (0.2 to 4 mmol/L) and pH values of 0 and 10.5, respectively. In the case of both of these vanadium species, the zirconium titanate mesophases displayed relatively slow kinetics, taking in excess of about 500 min to achieve maximum uptake. By using a pseudo-second-order rate law, it was possible to extract the instantaneous and overall rate of the adsorption processes and then relate these to the pore diameters. Both the instantaneous and overall rates of adsorption increased with increasing surface area and pore diameter over the studied pore size range. However, the equilibrium adsorption capacity increased linearly with pore diameter only for the higher concentrations and was independent of pore diameter for the lower concentration. These results have been interpreted using a model in which discrete adsorption occurs at low concentrations and is then followed by multilayer adsorption at higher concentration. 相似文献
16.
M. A. Rauf S. M. Hasany M. T. Hussain 《Journal of Radioanalytical and Nuclear Chemistry》1989,132(2):397-408
The adsorption of mercury on zirconium oxide from aqueous solution has been studied in relation to concentration of adsorbent and adsorbate. The influence of contact time, buffer composition, pH, and foreign ions was also investigated. Thiosulfate, iodide, thiocyanate, EDTA, cyanide and Li(I) drastically reduced adsorption. Adsorption of other metal ions under the same conditions was also investigated. Based on these data, separation of mercury from antimony and neodymium can be achieved. 相似文献
17.
Many people worldwide are exposed to extreme levels of fluoride in drinking water. It is, therefore, critical to develop inexpensive, locally available, and environmentally friendly adsorbents for fluoride-laden water defluoridation. In the current study, virgin scoria (volcanic rock) from Ethiopia, was modified with zirconium oxide and used as an adsorbent in a fixed-bed column aiming at the removal of fluoride from water. The adsorption capability of zirconium oxide-coated scoria (ZrOCSc) was compared with unmodified virgin scoria (VSco). XRD, FTIR, XRF, SEM, ICP-OES, and the pHPZC tests were evaluated to explore the adsorption mechanisms. Thermal analysis of VSco and ZrOCSc revealed lower total weight losses of 2.3 and 3.2 percent, respectively, owing to the removal of water molecules and OH species linked to metal oxides contained in the material. The effect of test conditions such as the pH of the solution and the influent flow rate on the adsorption capacity of the adsorbent was carefully studied. ZrOCSc exhibited the maximum removal capacity of 58 mg/kg, which was 4.46 times higher than the observations for VSco (13 mg/kg) at pH 2, and an initial flow rate of 1.25 mL/min. Breakthrough time increased with decreasing initial pH and flow rate. The adsorption experimental data under various test conditions were examined by the Thomas and Adams–Bohart models. Both models were found very effective in describing the experimental data with a correlation coefficient (R2) of ≥0.976 (ZrOCSc) and ≥0.967 (VSco). Generally, coating VSco with zirconium oxide improved the adsorption performance of VSco; hence, a ZrOCSc-packed fixed bed could be employed for the decontamination of high levels of fluoride from groundwater. However, further examination of the adsorbent using natural groundwater is advisable to produce a definitive conclusion. 相似文献
18.
Matyshak V. A. Il’ichev A. N. Sadykov V. A. Sil’chenkova O. N. Korchak V. N. 《Kinetics and Catalysis》2015,56(2):226-236
Kinetics and Catalysis - The zirconium dioxide surface has a wide variety of adsorption sites differing in their nature. The proportions of these sites can be changed by varying the oxide... 相似文献
19.
Blokhin A. A. Maiorov D. Yu. Kopyrin A. A. Taushkanov V. P. 《Russian Journal of Applied Chemistry》2002,75(12):1939-1944
A method for introduction of hydrated zirconium oxide into macroporous cation exchangers KU-23 and KM-2p and the acid-base properties and structural features of the composite ion exchangers are described. 相似文献
20.
Adsorption of CO2 on layered double oxides supported on graphene oxide has been studied under dry and wet conditions. In the first exposure to the adsorptive gas, the isotherms obtained for supported and unsupported materials are shown to fit to the Freundlich model indicating the existence of heterogeneous adsorption sites. After multiple temperature-swing cycles, the adsorption capacity decreased and the data is better described by the Langmuir model. The presence of graphene oxide is shown to reduce the loss of adsorption capacity, and helps to maintain the heterogeneity of the basic sites on the adsorbents. The use of wet gas mixtures was found to have a positive effect on the CO2 adsorption capacity of the graphene oxide hybrids. The presence of residual sodium on the materials resulted in a Freundlich isotherm with increased adsorption capacity. 相似文献