Clarification of Adsorption Reversibility on Granite that Depends on Cesium Concentration

We investigated the fate of radioactive cesium (134Cs plus 137Cs) during the production of tofu, natto, and nimame (boiled soybean) from a contaminated Japanese soybean cultivar harvested in FY2011. Tofu, natto, and nimame were made from soybean grains containing radioactive cesium (240 to 340 Bq/kg [dry weight]), and the radioactive cesium in the processed soybean foods and in by-product fractions such as okara, broth, and waste water was measured with a germanium semiconductor detector. The processing factor is the ratio of radioactive cesium concentration of a product before and after processing. For tofu, natto, nimame, and for the by-product okara, processing factors were 0.12, 0.40, 0.20, and 0.18, respectively; this suggested that these three soybean foods and okara, used mainly as an animal feed, can be considered safe for human and animal consumption according to the standard limit for radioactive cesium of soybean grains. Furthermore, the ratio of radioactive cesium concentrations in the cotyledon, hypocotyl, and seed coat portions of the soybean grain was found to be approximately 1:1:0.4.

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Cesium concentration effect on Pt/Cs beta zeolite/γ-alumina catalysts for n-heptane conversion

Applied Catalysis A General ◽

10.1016/s0926-860x(02)00073-x ◽

2002 ◽

Vol 231 (1-2) ◽

pp. 117-123 ◽

Cited By ~ 4

Author(s):

G. Espinosa Sntamaaria ◽

J.M. Bautista ◽

H. Silva ◽

L. Muñoz ◽

N. Batina

Keyword(s):

Concentration Effect ◽

Beta Zeolite ◽

Cesium Concentration ◽

Heptane Conversion ◽

Alumina Catalysts

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Distribution Coefficients and Apparent Diffusion Coefficients of Cesium in Compacted Bentonites

MRS Proceedings ◽

10.1557/proc-556-1091 ◽

1999 ◽

Vol 556 ◽

Cited By ~ 4

Author(s):

Akiko Okamoto ◽

Kazuya Idemitsu ◽

Hirotaka Furuya ◽

Yaohiro Inagaki ◽

Tatsumi Arima

Keyword(s):

Diffusion Coefficients ◽

Distribution Coefficients ◽

Dry Density ◽

Apparent Diffusion Coefficients ◽

Compacted Bentonite ◽

Apparent Diffusion ◽

Tracer Solution ◽

Cesium Concentration ◽

Penetration Profile ◽

Very High

AbstractDistribution coefficients and apparent diffusion coefficients of cesium in some compacted bentonites were determined by the penetration profile method. Cylindrical compacted bentonites with the dry density of 0.8 to 1.6 Mg/m3 were contacted with tracer solutions containing 1000, 100 or 10 ppm of cesium. The apparent diffusion coefficients were obtained from the concentration profiles of cesium in compacted bentonites. The distribution coefficients were obtained concurrently by dividing the intercepts of the profiles by the concentration of the tracer solution. The apparent diffusion coefficients of cesium in compacted bentonite were obtained in the range of 0.42 to 9.6· 10−12 m2/s. The apparent diffusion coefficients in the compacted bentonite contacted with three different concentrations of cesium tended to decrease with increasing dry density of the specimen; but, they had no dependence on cesium concentration within a factor of 3 at the same dry density. The distribution coefficient of cesium for the specimens contacted with three different concentrations of cesium were obtained in the range of 0.3 to 90 L/kg and had little dependence on dry density. The distribution coefficients obtained in the compacted bentonites were dependent on pH of the solution rather than concentration of cesium. These distribution coefficients obtained in the compacted bentonites were 10 to 1000 times smaller than those obtained by batch experiments. The data suggest that not all sorption sites for cesium are available in highly compacted bentonite. It is necessary to consider surface diffusion as a significant migration mechanism of cesium through the compacted bentonites at very high pH condition such as 12.

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Adsorptive Removal of Cesium Ions Using Prussian Blue Immobilized Coffee Ground Biochar

Journal of Korean Society of Environmental Engineers ◽

10.4491/ksee.2021.43.5.336 ◽

2021 ◽

Vol 43 (5) ◽

pp. 336-346

Author(s):

Youngsu Lim ◽

Dongwoo Kim ◽

Jiseon Jang ◽

Bolam Kim ◽

Dae Sung Lee

Keyword(s):

Prussian Blue ◽

Surface Structure ◽

Maximum Adsorption Capacity ◽

Radioactive Cesium ◽

Characteristic Analysis ◽

Adsorptive Removal ◽

Cesium Ions ◽

Cage Size ◽

Coffee Ground ◽

Cesium Concentration

Objectives: Among various radioactive contaminants, radioactive cesium is one of the most harmful radionuclides that causes human health issues due to its high emission of gamma-ray, high solubility, high mobility, high fission yield, and long half-life. Different kinds of adsorbents have been developed for the removal of cesium from radioactive wastewater. Especially, biochar has attracted great attention as a potential adsorbent in the treatment of pollutants and for water purification. In addition, Prussian blue is a cubic lattice structure that contains a cage size similar to the hydrated cesium ionic radius, indicating it can selectively remove cesium ions. Therefore, the aim of this study is to investigate the cesium adsorption performance of synthesized Prussian blue-immobilized coffee ground biochar (PB-CGBC) under various experimental conditions for cesium removal from radioactive wastewater.Methods: After wasted coffee ground was washed and dried, it was heated at 400℃ with 10℃/min of heating rate and 5 h of retention time in a furnace with little or no available air. The PB-CGBC was synthesized using a facile co-precipitation method. Fourier transform-infrared spectroscopy, X-ray diffractometer, field emission-transmission electron microscope, Brunauer-Emmett-Teller, and zeta potential analyzer were used to analyze physico-chemical characteristics and surface structure of the synthesized adsorbents. The kinetic and equilibrium experiments of cesium adsorption on PB-CGBC were carried out and the effect of pH, temperature, initial cesium concentration, and contact time were also investigated in a batch system.Results and Discussion: The characteristic analysis clearly confirmed the successful synthesis of PB-CGBC, indicating its abundant functional groups and special surface structure. In the batch study, it was found that the cesium adsorption onto the PB-CGBC was exothermic nature. The Elovich kinetic model and Temkin isotherm also provided a good correlation with the cesium adsorption reaction onto the PB-CGBC. The maximum adsorption capacity of PB-CGBC for cesium was 129.57 mg/g at 15℃ and pH 8 at 40 mM of an initial cesium concentration, which was one of the highest values among those of previously reported adsorbents.Conclusions: In this study, the PB-CGBC was synthesized by immobilizing Prussian blue to the surface of coffee ground biochar and successfully applied for the adsorptive removal of cesium ions. Based on the experimental results, the synthesized PB-CGBC can be served as a great adsorbent for treatment of wastewater polluted with radioactive cesium.

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