Sugita, Tsuyoshi; Mori, Masanobu*; Kozai, Naofumi
Journal of Photochemistry and Photobiology A; Chemistry, 438, p.114548_1 - 114548_6, 2023/04
Removal of iodine from water contaminated by nuclear accidents or the release of radioactive waste is complicated and costly because iodine exists in a variety of forms in the water. We investigated the unification of iodine species by photocatalysis as a pretreatment for removing radioactive iodine species from water. The effect of the TiO crystal phase of Pt-TiO and solution pH on the photocatalytic redox reactions of iodide (I), iodate (IO), and -iodobenzoic acid were evaluated. The choice of TiO crystalline phase and pH allowed the mixture of iodine species to be unified to only I or IO. Regardless of the type of Pt-TiO, the iodine in o-iodobenzoic acid was mineralized to I under alkaline conditions. Because the iodine species can be unified to a single species by selecting the photocatalyst and the solution pH, this photocatalytic treatment could be applied to remove iodine species with high efficiency.
Miura, Daisuke*; Sekine, Yurina; Nankawa, Takuya; Sugita, Tsuyoshi; Oba, Yojiro; Hiroi, Kosuke; Ozawa, Tatsuhiko
Carbohydrate Polymer Technologies and Applications (Internet), 4, p.100251_1 - 100251_9, 2022/12
The reaction mechanism of carboxymethyl cellulose nanofiber (CMCF) hydrogel formed by freeze-crosslinking was investigated. We succeeded in observing the hierarchical structural changes during the freeze-crosslinking reaction. Freeze-crosslinked CMCF hydrogels exhibited a characteristic hierarchical alignment structure from the angstrom to micrometer scale that differed from normal cross-linked CMCF hydrogels produced by a conventional method without freezing. It was shown that the characteristic hierarchical structure contributes the excellent mechanical properties of freeze-crosslinked CMCF hydrogels.
Ueda, Yuki; Eguchi, Ayano; Tokunaga, Kohei; Kikuchi, Kei*; Sugita, Tsuyoshi; Okamura, Hiroyuki; Naganawa, Hirochika
Industrial & Engineering Chemistry Research, 61(19), p.6640 - 6649, 2022/05
no abstracts in English
Sekine, Yurina; Nankawa, Takuya; Yamada, Teppei*; Matsumura, Daiju; Nemoto, Yoshihiro*; Takeguchi, Masaki*; Sugita, Tsuyoshi; Shimoyama, Iwao; Kozai, Naofumi; Morooka, Satoshi
Journal of Environmental Chemical Engineering, 9(2), p.105114_1 - 105114_12, 2021/04
Remediating toxic ion contamination is crucial for protecting human health and the environment. This study aimed to provide a powerful strategy for effectively utilizing bone waste from the food production and preparation industries for removal of toxic ions. Here, we show that immersing pig bone in NaHCO solution produced a carbonated nanohydroxyapatites (C-NHAP). The C-NHAP exhibited high adsorptivity for Sr, Cd, Pb, and Cu. The strontium adsorptivity was about 250 and 4,500 times higher than that of normal bone and synthetic HAP, respectively. The C-NHAP is an eco-friendly, high-performance material that is simple to prepare and should be useful for tackling problems of food waste disposal and environmental pollution.
Ueda, Yuki; Kikuchi, Kei*; Tokunaga, Kohei; Sugita, Tsuyoshi; Aoyagi, Noboru; Tanaka, Kazuya; Okamura, Hiroyuki
Solvent Extraction and Ion Exchange, 39(5-6), p.491 - 511, 2021/00
no abstracts in English
Sekine, Yurina; Nankawa, Takuya; Yunoki, Shunji*; Sugita, Tsuyoshi; Nakagawa, Hiroshi; Yamada, Teppei*
ACS Applied Polymer Materials (Internet), 2(12), p.5482 - 5491, 2020/12
We developed a cross-linking method using freeze concentration and used it to synthesize a new type of carboxymethyl cellulose nanofiber (CMCF) hydrogel with high compressive strength ( 80 MPa) and high compressive recoverability. The hydrogels were prepared by adding an aqueous solution of citric acid (CA) to a frozen CMCF sol and then thawing the sol. The reaction between the freeze-concentrated CMCF and CA created a rigid porous structure that reflected the ice crystal structure. Their cross-linked structure has a high stability to compressive stress. Bentonite was immobilized on a CMCF hydrogel by adding bentonite to the CMCF sol before freeze cross-linking. The CMCF-bentonite hydrogel showed high adsorptivity for chemical dyes. The physically cross-linked CMCF hydrogels are non-toxic, metal-free, and simple to prepare, and thus they may be useful as sustainable materials in various fields.
Sugita, Tsuyoshi; Kobayashi, Kentaro*; Yamazaki, Taiki*; Isaka, Mayu*; Itabashi, Hideyuki*; Mori, Masanobu*
Journal of Photochemistry and Photobiology A; Chemistry, 400, p.112662_1 - 112662_8, 2020/09
In this study, we developed an in-line photocatalytic performance evaluation system in which a flow reactor was connected to the ion chromatography to accurately evaluate the performance of the photocatalyst. This system was used to evaluate the photocatalyst supported by the two-layer support method on the substrate, such as glass beads. The performance of the photocatalyst was evaluated using dimethyl sulfoxide (DMSO), and it was possible to monitor the decomposition of DMSO by UV and the formation of by-products, such as methane sulfonate (MSO) and sulfate (SA). This system can be expected to be useful not only for evaluating the decomposition performance of an object using a photocatalyst but also for evaluating the byproducts.
Ueda, Yuki; Kikuchi, Kei; Sugita, Tsuyoshi; Motokawa, Ryuhei
Solvent Extraction and Ion Exchange, 37(5), p.347 - 359, 2019/07
We have newly-designed fluorous phosphate(TFP) for the effective Zr(IV) ion extractant as an alternative extractant against the conventional organic phosphate, tri--butyl phosphate(TBP). Zr(IV) ion extraction system using the TBP has many problems such as the formation of the third phase during liquid-liquid extraction. Here, we develop the fluorous extraction system based on the TFP-perfluorohexane for the Zr(IV) ion extraction to improve the Zr(IV) ion extraction system with an effective extractability and without the third phase formation. Our main findings were that the significant high extraction performance of the TFP for Zr(IV) ion as compared with TBP, and the origins of the high extraction performance of the TFP are related to the water and HNO contents in the fluorous phase and the stability of the complex, Zr(No)(TFP).
Mori, Masanobu*; Sugita, Tsuyoshi; Fujii, Kengo*; Yamazaki, Taiki*; Isaka, Mayu*; Kobayashi, Kentaro*; Iwamoto, Shinji*; Itabashi, Hideyuki*
Analytical Sciences, 34(12), p.1449 - 1453, 2018/12
The photocatalyst coating stainless-steel wire mesh (TiO-WM) was prepared by double-layer coating method. The TiO-WM was evaluated using flow analytical system, which included the reactor and conductimetric detector (FAS-CD). The DMSO decomposition test through the FAS-CD reveal that photocatalytst was stable coating on the stainless-steel wire mesh.
Atanassova, M.*; Okamura, Hiroyuki; Eguchi, Ayano; Ueda, Yuki; Sugita, Tsuyoshi; Shimojo, Kojiro
Analytical Sciences, 34(8), p.973 - 978, 2018/08
The distribution constants of 4-benzoyl-3-phenyl-5-isoxazolone (HPBI) and deprotonated one (PBI) between hydrophobic ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([CCim][TfN]) and aqueous phases were determined, together with the acid-dissociation constant of HPBI. The solvent extraction of three selected lanthanoid ions (La, Eu, and Lu) with HPBI from aqueous nitrate phase into [CCim][TfN] has been investigated. Application of the ionic liquid as the extracting phase greatly enhanced the extraction performance of HPBI for lanthanoid ions compared with that in the chloroform system. The composition of the extracted species was established to be anionic tetrakis entities, Ln(PBI), for light, middle, and heavy lanthanoid ions in an ionic environment.
Sekine, Yurina; Kim, S. B.*; Zhang, Y.*; Bandodkar, A. J.*; Xu, S.*; Choi, J.*; Irie, Masahiro*; Ray, T. R.*; Kohli, P.*; Kozai, Naofumi; et al.
Lab on a Chip, 18(15), p.2178 - 2186, 2018/08
The rich composition of solutes and metabolites in sweat and its relative ease of collection upon excretion from skin pores make this class of biofluid an attractive candidate for point of care analysis. Here, we present a complementary approach that exploits fluorometric sensing modalities integrated into a soft, skin-interfaced microfluidic system which, when paired with a simple smartphone-based imaging module, allows for in-situ measurement of important biomarkers in sweat. A network array of microchannels and a collection of microreservoirs pre-filled with fluorescent probes that selectively react with target analytes in sweat (e.g. probes), enable quantitative, rapid analysis. Field studies on human subjects demonstrate the ability to measure the concentrations of chloride, sodium and zinc in sweat, with accuracy that matches that of conventional laboratory techniques.
Sugita, Tsuyoshi; Kobayashi, Kenichi*; Kobayashi, Kentaro*; Yamazaki, Taiki*; Fujii, Kengo*; Itabashi, Hideyuki*; Mori, Masanobu*
Journal of Photochemistry and Photobiology A; Chemistry, 356, p.71 - 80, 2018/04
Photocatalysts shows high redox property only by light irradiation. However, the reaction performance is lowered in aqueous phase due to the low contact efficiency between catalyst and targets. In this study, to enhance aqueous adsorption and photodecomposition of anionic organic target, we developed an amino functional-based spacer (3-[2-(2- aminoethylamino)ethylamino]propyl-trimethoxysilane, DETA), and used it to modify TiO. The modified catalyst with positively charged amino groups could enhance the adsorption and photodecomposition of anionic organic targets.
Sugita, Tsuyoshi; Fujiwara, Iori*; Okamura, Hiroyuki; Oshima, Tatsuya*; Baba, Yoshinari*; Naganawa, Hirochika; Shimojo, Kojiro
Solvent Extraction Research and Development, Japan, 24(2), p.61 - 69, 2017/05
We investigated an influence of amide group in diglycolamic acid-type extractants on extraction property of metal ions. The extraction characteristics of -dodecyldiglycolamic acid (CDGAA), with a secondary amide group, for 56 metal ions have been investigated, and compared with those of -dioctyldiglycolamic acid (DODGAA) with a tertiary amide group. Compared with DODGAA, CDGAA has a poor extraction performance and separation ability for rare-earth metal ions, except for Sc(III). However, CDGAA tended to provide better extraction for relatively small-sized metal ions than DODGAA. In addition, it was found that CDGAA enables the selective removal of Hg(II) from aqueous solutions containing various divalent metal ions.
Journal of Flow Injection Analysis, 33(1), p.39 - 40, 2016/06
A novel solvent extraction way, emulsion flow (EF) method, has been developed at JAEA. EF method achieves both good emulsion formation and quick phase separation only by solution sending. In this report, I referred Flow Injection Analysis (FIA) using solvent extraction as a preprocessing technique and introduced an outline of the EF method as such. Furthermore, I mentioned the application possibility of the EF method to the preprocessing in FIA with its advantage for extracting and concentrating a trace component from a large-volume sample.
Shimojo, Kojiro; Fujiwara, Iori*; Fujisawa, Kiyoshi*; Okamura, Hiroyuki; Sugita, Tsuyoshi; Oshima, Tatsuya*; Baba, Yoshinari*; Naganawa, Hirochika
Solvent Extraction Research and Development, Japan, 23(2), p.151 - 159, 2016/05
Liquid-liquid extraction of rare-earth (RE) cations has been investigated using -dodecyldiglycolamic acid (CDGAA) with a secondary amide group, and compared with that using -dioctyldiglycolamic acid (DODGAA) with a tertiary amide group. CDGAA enables quantitative transfer of all RE cations from moderately acidic solution, while being selective toward the heavier RE cations, and performs better than typical carboxylic-acid-type extractants. However, CDGAA provides low extraction performance and separation ability for RE cations compared with DODGAA because of the weaker basicity of the amide oxygen. Slope analysis demonstrated that RE transfer with CDGAA proceeded through a proton-exchange reaction, forming a 1:3 complex, RE(CDGAA). Structural characterization by X-ray diffraction revealed that three -butyldiglycolamic acid (CDGAA) molecules coordinated to the La central ion in a tridentate fashion and the La primary coordination sphere consisted of three oxygen atoms from the amide group, three oxygen atoms from the ether group, and three oxygen atoms from the carboxy group.
Iwatsuki, Teruki; Sato, Haruo; Nohara, Tsuyoshi; Tanai, Kenji; Sugita, Yutaka; Amano, Kenji; Yabuuchi, Satoshi; Oyama, Takuya; Amano, Yuki; Yokota, Hideharu; et al.
JAEA-Research 2011-009, 73 Pages, 2011/06
The research and development plan in Horonobe Underground Research Laboratory are summarized according to the 2nd Midterm Plan till 2014 fiscal year of JAEA. In this midterm, galleries and the infrastructures for the research and development up to the depth of 350 m are constructed by Private Financial Initiative (PFI). Additionally Phase 3: Operation phase at the galleries begins in parallel to Phase 2: Construction phase. In these phases various research and development including collaboration with other institutes are conducted at the galleries. Generallic applicable techniques on the subject of the investigation of geological environment, facility construction in deep underground and the reliability of geological deposal are developed during the phase. The feasibility and reliance of various technologies concerning geological disposal is demonstrated by widely opening the outcome to the public in the society.
Sato, Haruo; Amano, Kenji; Niizato, Tadafumi; Tanaka, Shingo; Nohara, Tsuyoshi; Iwatsuki, Teruki; Murakami, Hiroaki; Sugita, Yutaka; Nakayama, Masashi; Abe, Hironobu; et al.
no journal, ,
Accident of Fukushima Daiichi Nuclear Power Station, TEPCO occurred by Tsunami caused by Tohoku Pacific Ocean Earthquake on 11 March, 2011. Part of the radionuclides in atomic reactors was released and accumulated on soil surface over the wide range of area in Fukushima Prefecture by rain after being transported by wind. This work was carried out as one of the projects which were published by Council for Science and Technology Policy on 19 May and investigation on the depth distribution of radionuclides in soil was carried out. Also the inventories of radionuclides accumulated on soil surface immediately after the occurrence of accident were estimated. In this presentation, we report the apparent diffusion coefficients Da of radionuclides and the inventories of radionuclides on soil surface immediately after the occurrence of accident among a series of investigation and research. Cs and Cs were detected in all investigation points (11 points), and Te and Ag were detected only in areas where spatial dose rate and the inventories of radionuclides have been evaluated to be high. The depth distributions of radionuclides were less than 5cm from surfaces except for the soil of farmland at many points. Radionuclides tended to be detected in deeper positions in the soil of farmland than in the soil of surface. Da values derived from the depth distributions for all radionuclides were nearly 1E-11 (m/s) for the soil of many points except for the soil of farmland. This is considered to be due to that those Da values were controlled by dispersion. The estimated inventories of radionuclides accumulated on soil surface immediately after the occurrence of accident were consistent with monitoring results so far.
Tanaka, Shingo; Sato, Haruo; Niizato, Tadafumi; Amano, Kenji; Nohara, Tsuyoshi; Iwatsuki, Teruki; Murakami, Hiroaki; Sugita, Yutaka; Nakayama, Masashi; Abe, Hironobu; et al.
no journal, ,
The sorption distribution coefficients of cesium and iodine onto the soil are studied. The batch sorption experiments were conducted onto the 24 specimens obtained from 11 sites (12 geoslicers) at each two different depth compartment. The experiments were based on the way standardized by Atomic Energy Society of Japan. The Kd values of cesium ranged from 1,000 to 100,000 ml/g, corresponding to the result that most of the cesium in the investigation sites are stayed in the surface of the ground. On the other hand, the Kd values of iodine ranged from 0.4 to 150 ml/g. It is likely that the difference of Kd values is affected by not only the chemical form of the elements between cesium and iodine, but also mineral composition, cation and anion exchange capacities, content of organic matter, and so on. This investigation initially focuses on varieties of soil, such as sandy or clayey soil, and soil colors.
Niizato, Tadafumi; Sato, Haruo; Amano, Kenji; Nohara, Tsuyoshi; Iwatsuki, Teruki; Aoki, Kazuhiro; Tanaka, Shingo; Murakami, Hiroaki; Sugita, Yutaka; Nakayama, Masashi; et al.
no journal, ,
Investigation and research on depth distribution in soil of radionuclides released by accident of Fukushima Daiichi Nuclear Power Station, TEPCO.
Aoki, Kazuhiro; Sato, Haruo; Niizato, Tadafumi; Amano, Kenji; Tanaka, Shingo; Nohara, Tsuyoshi; Iwatsuki, Teruki; Murakami, Hiroaki; Sugita, Yutaka; Nakayama, Masashi; et al.
no journal, ,
Field survey on depth distribution in soil of radionuclides released by accident of Fukushima Daiichi Nuclear Power Station was conducted by using Geoslicer. Investigation was conducted in the middle of June after 3 months of the accident. This paper reports the outline of the investigation.