Adsorption Behavior Of Cesium Research Articles

Adsorption Behavior of Cesium on Hybrid Microcapsules in Spent Fuel Solution

Adsorption Behavior of Cesium on Hybrid Microcapsules in Spent Fuel Solution

First-principle studies of radioactive fission productions of Cs/Sr/Ag/I adsorption on silicon carbide in HTGR

Silicon carbide (SiC) is one of the important fuel-element materials in high-temperature gas-cooled reactors (HTGRs), and learning the adsorption behavior of radioactive fission products on the SiC surface is essential for source-term analysis in HTGR. In this study, the adsorption behavior of cesium, strontium, silver, and iodine on β-SiC is investigated using first-principle calculations. We find that the interactions between the adatoms and SiC substrate are strong for all four types of nuclides with binding energy of approximately 1–3 eV. These results are confirmed again by analysis of the charge density difference and density of state. Furthermore, the adsorption rates of the four nuclides are obtained, and we explain that these nuclides display significant adsorption rate on the SiC surface but are not easily desorbed, which shows that the solid fission products have difficulty penetrating through the SiC. These results demonstrate that in HTGR, intact SiC could effectively obstruct the diffusion of fission products from the uranium dioxide in tri-isotropic (TRISO) particles to the primary circuit, which are first obtained in a micro perspective.

Adsorption behavior of cesium and strontium onto chitosan impregnated with ionic liquid

ABSTRACTWe briefly studied the adsorption behavior of chitosan impregnated with an ionic liquid (1-ethyl-3-methyl imidazolium chloride) in solutions with Cs+ and Sr2+ ions. The impregnation of chitosan was realized by ultrasonication method. The impregnated chitosan was analyzed by FTIR, SEM, and EDX in order to show that the chitosan was impregnated with the studied IL. The adsorptive properties of ionic liquid-impregnated chitosan for the removal of Cs+ and Sr2+ ions from aqueous solutions were studied in a batch adsorption system. The adsorption kinetic was found to follow a pseudo-second-order kinetic model. The experimental data showed good fit to the Langmuir isotherm. The adsorption properties of the chitosan impregnated with the studied ionic liquid were determined in binary, tertiary, and quaternary systems. The adsorption capacity of the IL impregnated chitosan is not significant influenced in the binary systems. The adsorption capacity of the IL impregnated chitosan decreases with the increase of the number of the cation present in solutions. It was observed that the studied adsorbent has a higher affinity for Cs+ ions than for Sr2+ ions.

First-principle studies of radioactive fission productions Cs/Sr/Ag/I adsorption on chrome–molybdenum steel in Chinese 200 MW HTR-PM

Chrome–molybdenum steel (2·1/4Cr1Mo) is one of the main products of steam generation. The adsorption behaviors of radioactive fission products on 2·1/4Cr1Mo surface are critical in the analysis of HTR-PM. Here, the adsorption behavior of cesium, strontium, silver and iodine on 2·1/4Cr1Mo was investigated with first-principle calculations that the Ag and I atoms prefer to be adsorbed at the square hollow site of the face-centered cubic iron cell with a binding energy of about 1 and 3 eV, respectively. In contrast, Cs and Sr atoms are not adsorbed on the surface of the 2·1/4Cr1Mo. These results are again confirmed via analysis of charge density differences and the densities of state. Furthermore, the adsorption rates of these fission products show that only I and Ag have significant adsorption on the metal substrate. These adsorption results explain the amount of adsorbed radionuclides for an evaluation of nuclear safety in HTR-PM. These micro-pictures of the interaction between fission products and materials are a new and useful way to analyze the source term.

Synthesis, characterization and adsorption behavior of cesium, cobalt, and europium on organic-inorganic hybrid exchanger

Polyacrylonitrile titanium tungstophosphate was prepared by mixing of polymer with the matrices of inorganic precipitate of titanium tungstophosphate to form composite cation-exchanger. Ion-exchange properties, thermal stability, distribution features and other performances were studied to understand the cation-exchange behavior of the obtained material. Physico-chemical properties of the material were determined using AAS, inductive coupled plasma spectrometry (ICPS), elemental analysis, IR, differential thermal and thermogravimetric analysis TGA-DTA, X-ray diffraction patterns (XRD), X-ray fluorescence spectrometry (XRF) and SEM studies. The material was found to be highly selective for Cs+ ion. The selectivity coefficients for different cations were determined, physical thermodynamic parameters such as the Gibbs free energy change ΔG*, entropy of activation ΔS*, and enthalpy (ΔH) were calculated.

The adsorption behavior of cesium on poly(N-isopropylacrylamide/itaconic acid) copolymeric hydrogels

In this study, N-isopropylacrylamide/itaconic acid (NIPAAm/IA) hydrogels prepared by irradiating with γ radiation were used in experiments on cesium ion adsorption. The cesium ion adsorption capacity of the hydrogels was investigated as a function of Cs+ concentration, pH and temperature. The adsorption behavior of cesium was evaluated by using the radiotracer method. The adsorption isotherm models were applied to the experimental data, and it was seen that Freundlich isotherm explained the adsorption better than Langmuir isotherm. Two simplified kinetic models including pseudo-first-order and pseudo-second-order equation were selected to follow the adsorption processes. The Cs+ adsorption could be best described by the pseudo-first-order equation. The thermodynamic parameters including ΔG°, ΔH° and ΔS° for adsorption processes of Cs+ on the hydrogel were also calculated, and the negative ΔH° and ΔG° confirmed that the adsorption process was exothermic and spontaneous.

INDICATION OF CESIUM ADSORPTION INTO ANGSTROM-SCALE OPEN SPACES IN SAPONITE CLAY MINERAL

Adsorption behavior of cesium (Cs) into angstrom-scale open spaces for the saponite clay mineral is investigated by making use of positronium (Ps) annihilation spectroscopy together with thermogravimetry and differential thermal analysis (TG–DTA). Ps annihilation spectroscopy reveals two kinds of open spaces with their sizes of ~ 3 Å and ~ 10 Å, respectively, after baking at 423 K for 8 h under the vacuum condition at ~ 10-5 Torr. The large open space is found to survive for the Cs -type saponite due to less hydration of the Cs cations even after the exposure to the air for 200 h. It is thus inferred that Cs is locally adsorbed in the angstrom-scale open spaces in the saponite clay minerals.

Adsorption behavior of cesium on montmorillonite-type clay in the presence of potassium ions

The adsorption behavior of Cs ions on a montmorillonite-type clay was investigated in the presence of potassium ions, using a radiotracer technique. The initial concentration of K+ added to the CsCl was between 10-4 and 10-1 mol/l. The addition of K+ to the CsCl solution at different concentrations (10-6-10-2 mol/l) reduced the amount of Cs+ adsorbed on clay. The maximum ratio of Cs+ exchanged, calculated from a linearized form of Langmuir plot was in agreement with the ion exchange isotherms of Cs-K ions. Sorption energy evaluated from the graph of corrected selectivity coefficients vs. equivalent fraction of Cs in the solid phase was compared to the energy values obtained from Dubinin-Radushkevich (D-R) isotherms. Freundlich isotherm parameters were used to characterize a site distribution function, which provides information about the affinity ratio of the adsorption sites of Cs+ and K+ ions. The ion exchange isotherm of Cs-K systems exhibited a Langmuir type curve for all K+ concentrations.

The adsorption behavior of cesium on silica gel

Cesium adsorption on silica gel has been studied as a function of different particle sizes (15, 40 and 63 μm), cation concentrations and temperatures. The adsorption behavior of cesium was evaluated by using the radiotracer method. The temperatures chosen for the study were 25°C, 40°C, and 60°C. Cesium concentrations were ranged between 1×10 −6–1×10 −3 M. The data were fitted to both Freundlich and Dubinin–Radushkevich isoterms. The thermodynamic parameters calculated from the adsorption results were used to explain the mechanism of the adsorption.

Influence of soil/solution ratio on adsorption behavior of cesium on soils.

The influence of the ratio between soil weight and solution volume (soil/solution ratio) on a distribution coefficient of cesium for coastal sandy soil, kaoline and silica sand to water has been studied. The distribution coefficients of 137Cs for the soils decreased with the increase of the soil/solution ratios. The concentration of the cations dissolved from the soils into the solution varied with the soil/solution ratio. However, when the concentration of coexistent cations kept to be 10–2 mol/l, the distribution coefficient was kept constant at different soil/solution ratios. These results show that the soil/solution ratio does not directly affect on the adsorption of 137Cs on the soils, but the variation in the concentration of dissolved cations with the soil/solution ratio results in the change in the distribution coefficient.

Adsorption of cesium on minerals: A review

The adsorption behavior of cesium on pure minerals is reviewed. Although this field has been investigated intensively, the data are extremely variable in scope and interpretation with detailed information being available for only a few minerals. In current investigations in this field, the emphasis is on the nature of the adsorption sites and identification of these sites using spectroscopic techniques. In the first section of this review, the general mechanism of cesium adsorption is discussed and this is followed by consideration of the effect of parameters such as cesium concentration, the properties of the mineral and the characteristics of the solution phase, on cesium adsorption. Finally, interaction of cesium with some different minerals is described in some detail.

Adsorption Behavior of Cesium and Strontium on Synthetic Zeolite P

Abstract Adsorption behavior of Cs and Sr on a synthetic zeolite P has been studied. Natural zeolites, clinoptilolite and mordenite, were converted into the zeolite P having a high crystallinity through hydrothermal treatment with NaOH solutions. The distribution coefficient (Kd) for Cs+ and Sr2+ depended on pH in acidic region, while attained nearly constant values around 103cm3/g in neutral and alkaline regions. This value is almost the same as that for Cs+ and about ten times that for Sr2+ on the original clinoptilolite. The adsorption obeys Langmuir-type isotherms, and the saturated amounts of Cs and Sr were respectively estimated to be 1.76 and 1.84 mmol/g. The zeolite P containing these cations was readily converted into a stable solid form consisting of pollucite and Sr-feldspar by calcination above 1,000°C.

Adsorption Behavior of Cesium and Strontium on Synthetic Zeolite P.

Adsorption Behavior of Cesium and Strontium on Synthetic Zeolite P.

Heat-treatment of crystalline hydrated titania fibers and adsorption behavior of uranium from sea water.

The relationship between heat-treated adsorbent and its adsorption behavior is studied by using crystalline hydrated titania, H2Ti4O9⋅nH2O and H2Ti2O5⋅nH2O fibers. The adsorption behavior of uranium from sea water was observed by using the adsorbents heat-treated at various temperatures, and was compared with that of cesium and strontium from aqueous solutions to find the adsorption mechanism. The fibrous H2Ti2O5⋅nH2O adsorbent heat-treated at 300°C gave the uranium uptake of 45.8μg/g in maximum after 5 days. The uranium uptake was independent on the exchangeable protons in interlayers, and was maximum on a most disordered intermediate phase during structural modification by heat-treatment. Anatase fibers modified by heat-treatment above 500°C gave the uptake of 25μg/g under the same conditions. The adsorption behavior of cesium and strontium is different from that of uranium, because the uptake of them decreases with the increase of heat-treatment temperature.