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保科 宏行; 瀬古 典明; 植木 悠二; 玉田 正男; 弥富 洋介
日本イオン交換学会誌, 21(3), p.153 - 156, 2010/09
The adsorbent was prepared by radiation induced graft polymerization of glycidyl methacrylate onto nonwoven polyethylene fabric in aqueous medium, and following chemical modification with N-methyl-D-glucamine. The adsorbents were packed into the column, 10 cm in internal diameter. The volume of adsorbent in column was 2,000 cm. The column was set into the adsorption equipment which consisted of pump, pre-filters and a fraction collector. The groundwater was pumped up from neutralization tank and was 1.2 ppm of boron concentration. After removed of in/organic compound by pre-filters, the groundwater was pumped into the column at various flow rates. As a result, the bed volume (BV) at breakthrough point were 1,400 and 1,250 at space velocity (SV) 50 and 100 h
, respectively. These values correspond to 0.7 and 0.5 mmol/g-adsorbent. However, the BV at breakthrough point significant decreased at SV 200 h
. In the case of SV 100 h
, the adsorption equipment with the graft adsorbent can treat to remove boron from 4,800 liters of groundwater a day.
Phiriyatorn, S.*; 保科 宏行; 瀬古 典明; 玉田 正男
日本イオン交換学会誌, 21(3), p.157 - 160, 2010/09
An adsorbent containing hydroxamic acid groups was synthesized by radiation-induced graft polymerization of methyl acrylate (MA) onto nonwoven fabric composed of polyethylene-coated polypropylene fiber. Graft polymerization was carried out in emulsified MA solution containing sodium dodecyl sulfate as an emulsifier in the presence of water. Conversion of the ester groups in the grafted MA moiety into the hydroxamic groups was performed by treatment with an alkaline solution of hydroxylamine. The adsorbent containing hydroxamic acid groups was investigated. The adsorbent (approximately 0.01g) can adsorb 99% of U, 99% of V, 97% of Cd, and 97% of Pb at pH, 5, 4, 7, and 6 respectively after contacted with 100 ml of 100 ppb metal solution for 24 hour. The breakthrough capacities were 1000, 1100, 5300, and 7600 bed volume for Cd, V, U, and Pb, respectively with 100 ppb metal solution at the space velocity of 200 h. These values correspond to 0.006, 0.013, 0.014, and 0.022 mmol/g-adsorbent. The selectivity for metal ions of hydroxamic acid type adsorbent was Pb
U
V
Cd.
山岸 功; 森田 泰治
日本イオン交換学会誌, 21(3), p.175 - 180, 2010/07
放射性廃液からセシウム(Cs)を分離するために、ケイ素(Si),チタン(Ti),ジルコニウム(Zr),ニオブ(Nb)及びタンタル(Ta)から成る2元系の混合酸化物を水熱条件下で合成した。これらのCsに対する選択性並びに化学的安定性を硝酸溶液中で調べた。SiあるいはTiのタンタル酸塩は、SiとTiの混合酸化物として知られるケイ酸チタンと同様に、3M硝酸溶液中でも100ml/g以上の高い分配係数を示した。上記のタンタル酸塩中のSiあるいはTi含有率を変化させてX線回折により分析すると、ペロブスカイト構造のNaTaOが減少してパイロクロア構造が形成されることがわかった。構造変化に対応して、3M硝酸溶液中でのCsイオン交換容量も、特定のモル比(Si/Ta=0.5あるいはTi/Ta=0.26)になるまで、SiあるいはTi含有率とともに増加することもわかった。タンタル酸塩のCs交換容量は90
Cの3M硝酸による浸出試験後も変わらなかったが、ケイ酸チタンの場合は結晶構造破壊のために浸出前の1/20に減少した。Siのタンタル酸塩は、結晶性の高いTiのタンタル酸塩よりも吸着速度及びCs交換容量が大きいという特徴が認められた。
浅井 志保; 木村 貴海; 三好 和義*; 斎藤 恭一*; 山田 伸介*; 廣田 英幸*
日本イオン交換学会誌, 21(3), p.334 - 339, 2010/07
Estimation of internal radiation exposure using urine is helpful for screening the level of radiation exposure. Inductively coupled plasma mass spectrometry has been widely employed for the determination of radionuclides in urine. Prior to the measurements, mineral components in urine sample are removed to alleviate the instrumental damage. In this study, diethylamino-group containing porous-disk-packed cartridge (DEA cartridge) was applied to the separation of U in urine. The DEA cartridge was prepared by graft-polymerization and the subsequent introduction of a diethylamino group. U in urine was adsorbed onto the DEA cartridge and quantitatively eluted by permeating 5 mL of dilute nitric acid. The concentration of the U in the urine was agreed well with the mean concentration for unexposed Japanese individuals. The time required to accomplish the procedure was 20 minutes. A simple and rapid removal of the mineral component with high concentration was demonstrated.
瀬古 典明; 保科 宏行; 笠井 昇; 植木 悠二; 玉田 正男; 桐生 俊幸*; 田中 和也*; 高橋 牧克*
日本イオン交換学会誌, 21(3), p.117 - 122, 2010/07
The concentration of scandium dissolved in the hot spring water of Yukawa River, which is located in Kusatsu Town, Gunma, Japan is 17 mg-Sc/ton; this resource corresponds to 1.2 tons in daily flow. We have developed experimental equipment that uses fibrous adsorbents and is capable of selectively collecting scandium from hot spring water. Scandium recovery was carried out by pumping into hot spring water an adsorbent that was packed into a column of 155 mm in inner diameter and 500 mm in height. Such equipment was placed in the Yukawa River at Kusatsu Town. This equipment could be scaled up from lab scale to pilot scale. We found that this system is capable of collecting 200 g/yr of scandium per column when hot spring water flows with 1,000 L/day.
Basuki, F.*; 瀬古 典明; 玉田 正男
日本イオン交換学会誌, 21(3), p.127 - 130, 2010/07
Scandium (Sc) was recovered from aqueous solution by using fibrous phosphoric adsorbent which was prepared directly by radiation-induced grafting of 2-hydroxyethyl methacrylate phosphoric acid onto polyethylene nonwoven fabrics. In batch adsorption evaluation, the grafted fibrous phosphoric adsorbent (FPA) has a high absorption rate for Sc uptake of 100 g/L, which was 99% adsorbed in contact time of 40 min. In column mode adsorption, the breakthrough point of Sc was independent of flow rate up to 1740 h
in terms of space velocity. In the range of pH 1-3, no significant change in the breakthrough point was observed, which was 700 bed volume (BV) and 250 BV for feeding solutions of 1 and 5 mg/L, respectively. The adsorbed Sc on FPA could be completely eluted by triammonium citrate and the FPA maintained its adsorption capability without any significant loss until 12 cycles of use.
Liyanage Don, C. N.*; 植木 悠二; 瀬古 典明; 保科 宏行; 玉田 正男
日本イオン交換学会誌, 21(3), p.123 - 126, 2010/07
Graft adsorbent attracts much attention as a superior metal adsorbent since its adsorption rate is over 10 times higher than that of a commercial granular resin. However, most of metal adsorbents are synthesized from non-biodegradable petroleum materials. The disposal of non-degradable adsorbent disturbs and damages the global environment. Polylactic acid (PLA) is a well-known biodegradable and plant-derived polymer. In this study, nonwoven PLA fabric was used as a trunk polymer of grafting to conserve the global environment and to reduce the consumption of petroleum resources. PLA-based metal adsorbent was synthesized by radiation-induced graft polymerization of 4-chloromethylstyrene onto a nonwoven PLA fabric followed by amination with ethylenediamine. The degree of grafting reached 80% under the optimized grafting conditions. The aminated adsorbent could effectively capture metal ions from weak acid and neutral solutions, and the adsorption capacities at pH 6 were 2.37, 0.32, 0.21 and 0.19 mmol/g for Cu, Cd
, Pb
and Zn
, respectively.
渡部 創; 佐野 雄一; 明珍 宗孝; 岡本 芳浩; 塩飽 秀啓; 池田 篤史; 鈴木 伸一; 矢板 毅
日本イオン交換学会誌, 21(3), p.189 - 194, 2010/07
Y-K edge X-ray absorption measurements on the extraction chromatography column revealed that distribution of Y ion and local structure around Y ion inside the column can be evaluated simultaneously. The ionic distribution and the local structure were derived from the X-ray absorption intensity and EXAFS analysis, respectively. Density profile of Y ion inside the packed column moved to downstream of the column and local structural parameters of the nearest O around Y changed by supplying eluent. The X-ray absorption spectroscopy of more than one element in the column is expected to reveal the separation mechanism of the extraction chromatography.