• Korean Journal of Soil Science and Fertilizer
• /
• v.19 no.2
• /
• pp.115-121
• /
• 1986

This experiment was conducted to examined the effects of the physico-chemical and mineral-logical properties of paddy soil on the desorption of $Cs^{137}$ from radionuclide, $Cs^{137}$ absorbed soils. 1. Adsorption of $Cs^{137}$ by paddy soil was very much and exchangeable fraction of $Cs^{137}$ extracted by ammonium acetate was very high compared to the water soluble fraction. Exchangeable fraction of $Cs^{137}$ in paddy soil decreased with the increase of potassium application and increased proportionally with the increase of $Cs^{137}$ treatment. 2. The distribution of several forms of $Cs^{137}$ in soils depend on the soil type. Average-distribution rates of water soluble, exchangeable and non-exchangeable fractions of $Cs^{137}$ in soils were 5.9%, 17.1% and 77.0%, respectively. 3. The desorption of $Cs^{137}$ from adsorbed soils decreased with increase of pH and exchangeable cations of the soils, but it increased as organic matter and clay content increase in soil. 4. Non-exchangeable adsorption of $Cs^{137}$ was high in the soils of which both Illite and Vermiculite were dominant.

• Korean Journal of Mineralogy and Petrology
• /
• v.36 no.2
• /
• pp.117-124
• /
• 2023

X-ray diffraction analysis, X-ray fluorescence analysis, thermal differential and thermos gravimetric analysis, cation exchange capacity analysis, and Cesium (Cs), Strontium (Sr) adsorption experiments were performed to investigate the physical and chemical properties of natural zeolite from Guryongpo in Korea. As a result of X-ray diffraction analysis, minerals such as mordenite, heulandite, clinoptilolite, and illite are contained, and as a result of X-ray fluorescence analysis, elements such as SiO₂, Al₂O₃, CaO, K₂O, MgO, Fe₂O₃ and Na₂O are contained, and the cation exchange capacity was 148.6 meq/100 g. As a result of thermal differential and thermos gravimetric analysis, it was confirmed that the thermal stability was excellent up to 600 ℃. As a result of the adsorption equilibrium experiment over time, the equilibrium was reached within 30 min. for Cesium (Cs) and within 8 hr. for Strontium (Sr), and the adsorption rates of Cesium (Cs) and Strontium (Sr) were 80% and 18%, respectively. As a result of the single-component isothermal adsorption experiment, in conformed to the Langmuir model, and the maximum Cesium (Cs) adsorption amount was 131.5 mg/g, which was high, while the Strontium (Sr) maximum adsorption amount was 29.5 mg/g, which was low. In the case of the natural zeolite used in this study, the content of minerals including 8-rings such as clinoptilolite, heulandite, and mordenite is high, showing high selectivity for Cesium (Cs).

• Journal of Radiation Protection and Research
• /
• v.8 no.1
• /
• pp.15-25
• /
• 1983

The sequential separation of Ru-103, Cs-137 and Ce-144 was carried out by organic cation exchanger, Amberite CG-120, and inorganic ion exchangers, silica gel and montmorillonite. The optimum conditions of Ru-103, Cs-137 and Ce-144 on Amberite CG-120 are 0.01M-, 0.01M- and 0.1IM- hydrochloric acid for the adsorption, and 3M-, 3M- and 5M-hydrochloric acid for the desorption, respectively. The optimum conditions of Ru-103, Cs-137 and Ce-144 on silica gel are pH 8, pH 8 and pH 8 for the adsorption. and 3M-, 1M- and 1M-hydrochloric acid for the desorption. respectively. The optimum conditions of Ru-103, Cs-137 and Ce-144 on montmorillonite are pH 8, 0.01M-hydrochloric acid and pH 4 for the adsorption, and 1M-, 5M- and 3M-hydrochloric acid for the desorption. respectively. The adsorption which occurs at lower ionic strength and the differences in desorption ionic strength are utilized for the separation of tracer mixture in continuous experiments. The individual separation of Ru-103, Cs-137 and Ce-144 can be carried out more efficiently with montmorillonite than with silica gel and Amberite CG-120.

• Economic and Environmental Geology
• /
• v.31 no.1
• /
• pp.11-20
• /
• 1998

The effects of the major cations ($Ca^{2+}$, $Mg^{2+}$, $K^+$, $Na^+$), complex-forming anions ($SO_4{^{2-}}$, $HCO_3{^-}$), and solution pH on the adsorption of $^{137}Cs$ and $^{90}Sr$ by kaolinite in groundwater chemistry were investigated. Three-dimensional Kd modelling designed by a statistical method was attempted to compare the relative effect among hydrated radii, charge and concentration of competing cations on the adsorption of Cs and Sr. The modelling results indicate that the hydrated radii of competing cations is the most important factor, and then their charges and concentrations are also important factors in order. The property of zeta potential of kaolinite particles was discussed in terms of the amphoteric reactions of a kaolinite surface affecting the adsorption of Cs and Sr. The ionic strength of competing cations on the adsorption of Cs and Sr exerts a greater effect than the solution pH. The sorption behaviour of Sr on kaolinite is also highly dependent on the concentration of bicarbonate. The speciation of Sr and the saturation state of a secondary phase were thermodynamically calculated by a computer program, WATEQ4F. This indicates that the change in solution pH with the concentration of bicarbonate and the precipitation of a strontianite ($SrCO_3$) are major factors controlling Sr adsorption behaviour in the presence of bicarbonate ion.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.26 no.10
• /
• pp.1528-1534
• /
• 1989

Photoeffects at the p-GaP semiconductor/CsNO3 electrolyte interface were investigated in terms of their current-voltage characteristics. The photoeffects at the semiconductor-electrolyte interfaces and their photocurrent variations are verified using Ar ion laser and continuous cyclic voltammetric methods. The mechanism of charge transfer at the photogeneration in the depletion layer rather than the photodecomposition of the p-GaP semiconductor electrode surface and/or the water photoelectrolysis. The adsorption of Cs+ ions at the interface is physical adsorption.

• Membrane and Water Treatment
• /
• v.13 no.5
• /
• pp.227-233
• /
• 2022

The objective of the study, to develop adsorbent based purifier for removal of radiological and nuclear contaminants from contaminated water. In this regard, 3-aminopropyl silica functionalized with ethylenediamine tetraacetic acid (APS-EDTA) adsorbent prepared and characterized by Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). Prepared APS-EDTA used for adsorptive studies of Cs(I), Co(II), Sr(II), Ni(II) and Cd(II) from contaminated water. The effect on adsorption of various parameters viz. contact time, initial concentration of metal ions and pH were also analyzed. The batch method has been employed using metal ions in solution from 1000-10000 ㎍/L, contact time 5-60 min., pH 4-10 and material quantities 50-200 mg at room temperature. The obtained adsorption data were used for drawing Freundlich and Langmuir isotherms model and both models were found suitable for explaining the metal ions adsorption on APS-EDTA. The adsorption data were followed pseudo second order reaction kinetics. The maximum adsorption capacity obtained 1.3037-1.4974 mg/g for above said metal ions. The results show that APS-EDTA have great potential to remove Cd(II), Co(II), Cs(I), Ni(II) and Sr(II) from aqueous solutions through chemisorption and physio-sorption.

• Korean Journal of Soil Science and Fertilizer
• /
• v.37 no.3
• /
• pp.136-142
• /
• 2004

Though diverse methods have been developed to characterize surface charge of soils and pure minerals, there is not still a reliable and rapid method for differentiating permanent charge from variable charge. Thus, it is needed to find out a reasonable method for measuring permanent and pH-dependent charge of soils. In this study various methods such as Cs-adsorption method, Hybrid model, $NH_4{^+}$-adsorption method and theoretical calculation of lattice charge were applied to measure permanent charge of montmorillonite and illite. Calculated lattice charge was $71.82cmol\;kg^{-1}$ and $14.20cmol\;kg^{-1}$ for montmorillonite and illite, respectively. The permanent charge measured by Cs-adsorption method were $78.23cmol\;kg^{-1}$ and $11.13cmol\;kg^{-1}$ for montmorillonite and illite, respectively. The differences between the values measured by Cs-adsorption method and the calculated lattice charge were not different significantly as $6.41cmol\;kg^{-1}$ and $3.07cmol\;kg^{-1}$. But, Hybrid model showed an underestimated values when applied to clay minerals with predominant amounts of permanent charge. The experimental results showed Cs-adsorption method was more reasonable for permanent charge measurement than the Hybrid model for illlte or montmorillonitetype clays.

• Textile Coloration and Finishing
• /
• v.19 no.4
• /
• pp.10-17
• /
• 2007

Chitosan(CS) and cellulose acetate(CA) composite films were prepared using formic acid as a cosolvent by casting, solvent evaporating and neutralization method. This study examines if the blending method, which uses formic acid as a cosolvent is efficient in improving the mechanical properties of CS film, especially wet strength and elongation. Formic acid is an effective cosolvent for the blend of CS and CA. Under wet condition, tensile strength and elongation of the composite films were obviously higher than those of the films made from pure CS. FTIR, DSC, and X-ray diffraction showed that the composite films exhibit a high level of compatibility and that strong interaction between the CS and CA was caused by intermolecular hydrogen bonding. The affinity series of composite film to transition metal ions are Cu(II) > Cd(II) > Cr(III). The adsorption of Cu((II) ion was shown to be highly pH sensitive.

• Journal of Industrial and Engineering Chemistry
• /
• v.68
• /
• pp.48-56
• /
• 2018

A potassium copper hexacyanoferrate (KCuHCF) embedded magnetic hydrogel bead (HCF-Mbead) was synthesized via a facile double crosslinking methods of $Fe^{3+}$ ionic binding and freeze-thaw for effective $Cs^+$ removal. The HCF-Mbead had a hierarchical porous structure facilitating fast access of $Cs^+$ ions to embedded active sites. The adsorbent showed enhanced $Cs^+$ removal properties in terms of capacity (69.2 mg/g), selectivity ($K_d=4{\times}10^4mL/g$, 1 ppm $Cs^+$ in seawater) and stability (>99.5% removal in pH 3~11) with rapid magnetic separation. This study further opens the possibility to develop an efficient material that links the integration of adsorption and recovery.

• Korean Chemical Engineering Research
• /
• v.62 no.2
• /
• pp.181-190
• /
• 2024

Here, we develop a centrifugal microfluidic reactor with simple, fast, and high-throughput manner for the generation of magnetic Janus micro-adsorbents (MAs). By using the multi-micronozzle consisting of two separate aligned needles and centrifugal tubes, we have synthesized highly monodispersed Prussian blue- and magnetic nanoparticle-laden micro-adsorbents (PB-MNP-MAs). The enhanced cesium (Cs⁺) adsorption was demonstrated by conducting the adsorption isotherm and kinetics experiment which can be contributed to the porous nature of the Ca-alginate networks with a high surface area of embedded PB nanoparticles, resulting to perform rapid adsorption activity within 10 min. After Cs⁺ adsorption process, the as-synthesized PB-MNP-MAs were successfully harvested by introducing the external magnetic fields. Therefore, we believe that our findings can be provided new direction towards the development of advanced functional adsorbents in biological and environmental fields.