• Journal of Environmental Science International
• /
• v.12 no.10
• /
• pp.1061-1069
• /
• 2003

The adsorption behaviors of strontium and cesium ions on fly ash, natural zeolites, and zeolites synthesized from fly ash were investigated. The zeolites synthesized from fly ash had greater adsorption capabilities for strontium and cesium ions than the original fly ash and natural zeolites. The maximum adsorption capacity of synthetic zeolite for strontium and cesium ions was 100 and 154 mg/g, respectively, It was found that the Freundlich isotherm model could fit the adsorption isotherm. The distribution coefficients (K$\_$d/) for strontium and cesium ions were also calculated from the adsorption isotherm data, The distribution coefficients decreased with increasing equilibrium concentration of strontium and cesium ions in solution. By studying the removal of cesium and strontium ions in the presence of calcium, magnesium, sodium, potassium, sulfate, nitrate, nitrite, and EDTA (in the range of 0.01 - 5 mM) it was found that these coexistence ions competed for the same adsorption sites with strontium and cesium ions.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.29 no.4
• /
• pp.25-31
• /
• 2021

In this research, in order to effectively utilize the petroleum residue pitch, it was used as an adsorbent for removal of cesium ion. In this experiment, acid modification (hydrochloric acid, sulfuric acid) treatment was performed on the adsorbent to improve the ability to remove low-concentration cesium ions dissolved in water. As a result, when the reaction was performed with 9 M sulfuric acid at 25 ℃ and for 240 min, the removal efficiencies of 1.0 and 2.5 mg/L cesium ions were 66 and 51%, respectively. In addition, as the adsorption time increased in the batch experiment, the removal capacity of 1.0 and 2.5 mg/L cesium ions was improved, and when the adsorption reached for 32 hr, the removal efficiencies were 72 and 68%, respectively. Also, in order to increase the ability to remove the remaining cesium ions, an experiment was performed by temperature change (25, 37, 49 ℃), and 1.0 and 2.5 mg/L cesium ions contained in water under the operating conditions of 49 ℃ and 32 hr showed removal efficiencies of 90 and 81%, respectively. Consequently, these experimental results were intended to be used as an adsorption technology that can economically treat low-concentration cesium ions contained in water.

• Progress in Superconductivity and Cryogenics
• /
• v.23 no.3
• /
• pp.26-31
• /
• 2021

Advanced classification of Cs contaminated soil by using a magnetic force-assisted selection pipe was investigated. A selection pipe is a device that sort particles depending on their particle size, based on the relationship between buoyancy, drag, and gravity force acting on the particles. Radioactive cesium is concentrated in small-particle size soil components with a large specific surface area. Hence, the volume of the Cs contaminated soil can be reduced by recycling the large-particle size soil components with low radioactive concentration. One of the problems of the selection pipe was that the radioactive concentration of the stayed soil in the selection pipe exceeds 8000 Bq/kg, which is the standard value of recycling of Cs contaminated soil, due to low classification accuracy. In this study, magnetic fields were applied to the lab-scale selection pipe from upper side to improve the classification accuracy and to reduce the radioactive concentration of the stayed soil.

• Korean Journal of Environmental Agriculture
• /
• v.2 no.1
• /
• pp.30-34
• /
• 1983

The present study was carried out to determine the effect of a radionuclide, cesium-137, in soybean, which is an element released usually from nuclear facilities. Soybean plants were grown on the pots treated with cesium-137 $0.5{\sim}60{\mu}Ci/1kg$ soil and the uptake, translocation and accumulation of the radiocesium in the plant parts were measured at different growth stage. The results are summarized as follows: 1) Visual toxic symptoms on the plants due to treatment of radioactive cesium were not observed up to $60{\mu}Ci/10Kg$ soil in a pot. 2) The uptake of cesium-137 in soybean plant was increased with increment of concentration applied, while the uptake of potassium was proportionally decreased, indicating to have an ion antagonistic relationship between them. 3) The absolute amounts of cesium-137 in the plants were gradually increased by the pod setting stage, but rather reduced at harvesting stage. The accumulation occurred more in the leaves and stems than the soybean seeds. 4) The rate of uptake was ranged from 0.069 to 0.005 with proportional decrease by increasing concentration applied and the rate of Cs-137 translocation from plants to seeds was averaged 38.6% in soybean plant. The concentration coefficient was 0.04 in the soybean seeds from the pots treated with $20{\mu}Ci$ of cesium-137 and decreased with increment of cesium-137 applied.

• Korean Journal of Materials Research
• /
• v.33 no.4
• /
• pp.151-158
• /
• 2023

In this study, a new type of composite material combined with carbonyl iron, a relatively strong ferromagnetic material, was prepared to overcome the current application limitations of Prussian blue, which is effective in removing radioactive cesium. The surface of the prepared composite was analyzed using SEM and XRD, and it was confirmed that nano-sized Prussian Blue was synthesized on the particle surface. In order to evaluate the cesium removal ability, 0.2 g of the composite prepared for raw cesium aquatic solution at a concentration of 5 ㎍ was added and reacted, resulting in a cesium removal rate of 99.5 %. The complex follows Langmuir's adsorption model and has a maximum adsorption amount (q_e) of 79.3 mg/g. The Central Composite Design (CCD) of the Response Surface Method (RSM) was used to derive the optimal application conditions of the prepared composite. The optimal application conditions achieved using Response optimization appeared at a stirring speed of pH 7, 17.6 RPM. The composite manufactured through this research is a material that overcomes the Prussian Blue limit in powder form and is considered to be excellent economically and environmentally when applied to a cesium removal site.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2001.09a
• /
• pp.191-194
• /
• 2001

The electrokinetic apparatus for remediation of the soil contaminated with Cs$^{+}$was designed. After kaolin clay was compulsorily contaminated by Cs$^{+}$ solution, the remediation characteristics by electrokinetic method were analyzed. After remediation experiment, the pH of the cathode side of the soil column was increased to 12.7 due to the generation of OH in cathode reservoir, but no hydroxide cesium form in the cathode side. Effluent rate from the cathode almost was constant and cesium concentration of effluent decreased with time passage. The 49% of a total of Cs$^{+}$ in the column was decontaminated for 0.4 day, the 72% of a total of Cs$^{+}$ in the column was decontaminated for 0.8 day, the 83% of a total of Cs$^{+}$ in the column was decontaminated for 1.2 days, the 89% of a total of Cs$^{+}$ in the column was decontaminated for 1.6 days, and the 93% of a total of Cs$^{+}$ in the column was decontaminated for 2.1 day Meanwhile, the predicted values of residual concentration by the developed model were quite similar to those obtained from experiments.m experiments.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.31 no.3
• /
• pp.65-71
• /
• 2023

Cesium discharged from nuclear power plants requires technology for safely treating, due to its harmfulness to the human body. In this work, activated carbon impregnated with triethylenediamine (TEDA) process was applied to effectively remove cesium dissolved in aqueous solution. The surfaces on the activated carbon were chemically modified with various TEDA concentrations (2.5, 5.0, 7.5, 10.0, and 12.5%) and the optimal TEDA concentration was obtained to be 5.0% by the assessment for cesium removal efficiency. In addition, when 5.0% TEDA-impregnated activated carbon was used to treat 5.0 and 10.0 mg/L of cesium, the removal efficiency was 71.5% and 61.1%, respectively. Also, it was found to be the chemical adsorption from the adsorption kinetics experiment by temperature change. A novel remediation technology developed in this study could be practically employed for removing cesium contained in surface and ground water.

• Mycobiology
• /
• v.46 no.4
• /
• pp.388-395
• /
• 2018

Radionuclides were deposited at forest areas in eastern parts of Japan following the Fukushima Daiichi Nuclear Power Plant incident in March 2011. Ectomycorrhizal (EM) fungi have important effects on radiocaesium dynamics in forest ecosystems. We examined the effect of colonization by the EM fungus Astraeus hygrometricus on the uptake of cesium (Cs) and potassium (K) by Pinus densiflora seedlings. Pine seedlings exhibited enhanced growth after the EM formation due to the colonization by A. hygrometricus. Additionally, the shoot Cs concentration increased after the EM formation when Cs was not added to the medium. This suggests that A. hygrometricus might be able to solubilize Cs fixed to soil particles. Moreover, the shoot K concentration increased significantly after the EM formation when Cs was added. However, there were no significant differences in the root K concentration between EM and non-EM seedlings. These results suggest that different mechanisms control the transfer of Cs and K from the root to the shoot of pine seedlings.

• Nuclear Engineering and Technology
• /
• v.42 no.5
• /
• pp.562-567
• /
• 2010

A One-Dimensional Water Flow and Contaminant Transport in Unsaturated Zone (FTUNS) code has been developed in order to interpret radionuclide migration in an unsaturated zone. The pore-size distribution index (n) and the inverse of the air-entry value ($\alpha$) for an unsaturated zone were measured by KS M ISO 11275 method. The hydraulic parameters of the unsaturated soil are investigated by using soil from around a nuclear facility in Korea. The effect of hydraulic parameters on radionuclide migration in an unsaturated zone has been analyzed. The higher the value of the n-factor, the more the cobalt concentration was condensed. The larger the value of $\alpha$-factor, the faster the migration of cobalt was and the more aggregative the cobalt concentration was. Also, it was found that an effect on contaminant migration due to the pore-size distribution index (n) and the inverse of the air-entry value ($\alpha$) was minute. Meanwhile, migrations of cobalt and cesium are in inverse proportion to the Freundich isotherm coefficient. That is to say, the migration velocity of cobalt was about 8.35 times that of cesium. It was conclusively demonstrated that the Freundich isotherm coefficient was the most important factor for contaminant migration.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.18 no.4
• /
• pp.421-437
• /
• 2020

This study provides an assessment on a proposed method for separation of cesium, strontium, and barium using electrochemical reduction at a liquid bismuth cathode in LiCl-KCl eutectic salt, investigated via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDS). CV studies were performed at temperatures of 723-823 K and concentrations of the target species up to 4.0wt%. Redox reactions occurring during potential sweeps were observed. Concentration of BaCl2 in the salt did not seem to influence the diffusivity in the studied concentration range up to 4.0wt%. The presence of strontium in the system affected the redox reaction of lithium; however, there were no distinguishable redox peaks that could be measured. Impedance spectra obtained from EIS methods were used to calculate the exchange current densities of the electroactive active redox couple at the bismuth cathode. Results show the rate-controlling step in deposition to be the mass transport of Cs+ ions from the bulk salt to the cathode surface layer. Results from SEM-EDS suggest that Cs-Bi and Sr-Bi intermetallics from LiCl-KCl salt are not thermodynamically favorable.