著者

武政 尚太 諸井 克哉 下前 祐也 石橋 智博 西村 竜一 新苗 正和

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.139, no.10, pp.47-51, 2023-10-31 (Released:2023-10-28)

参考文献数

10

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Ru(III) chlorocomplexes are poorly extracted into organic solvents, which is due to the charge of the complex as well as those inert character in chloride solutions, that is, formation of RuCl6-n(H2O)n(3-n)- (n=0-6). Therefore, it is difficult to extract Ru(III) by solvent extraction, and Ru(III) is currently separated and purified by the oxidative distillation method. If Ru can be separated and recovered from chloride solutions by solvent extraction, an efficient separation and recovery process for PGMs can be established. Therefore, it is important to investigate the solvent extraction of Ru(III) from chloride solutions. The authors have previously studied solvent extraction of Ru(III) with 2-ethylhexylamine (EHA), which is a primary amine extractant, from chloride solutions and shown that the extraction of Ru(III) with EHA from chloride solutions without the addition of Sn (II)was high. However, the stripping of Ru(III) was difficult. In the present study, extractions of Ru from hydrochloric acid solutions with EHA and octylamine (OA), which are primary amines, were tested to clarify the extraction of Ru and the stripping of Ru with various stripping solutions. The extraction efficiency of Ru with EHA and OA from hydrochloric acid solutions without the addition of Sn (II) was high. And also, it was found that Ru could be easily stripped from EHA with sodium sulfate solutions.

著者

中田 英喜 横島 美香 鈴木 祐麻 新苗 正和

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.135, no.11, pp.101-108, 2019-11-30 (Released:2019-11-28)

参考文献数

24

被引用文献数

3

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The objective of this study was to deepen the understanding of the immobilization process of selenium (VI)contaminated soil when using immobilization agents consist of MgO and iron (II) compounds. The objective was achieved by introducing diffusion cells that allows us to physically separate soil and immobilization agent, and measuring the valence of selenium as well as the concentrations in liquid, soil, and immobilization agent phases. Experimental data showed that the addition of immobilization agents induced desorption of selenium (VI) from the contaminated soil, and the desorbed selenium (VI) was reduced into selenium (IV) by iron (II) compounds. The formed selenium (IV) was then effectively immobilized by re-sorbing on soil particles and immobilization agents. Also found was that more amount of selenium (IV) was sorbed on the immobilization agents as hydration reaction of immobilization agents proceeded. These insights obtained in this study are fundamental but important information to fully elucidate the selenium (VI) immobilization mechanisms that are required to improve the reliability of immobilization technology.

著者

鈴木 祐麻 新苗 正和 真田 靖瑛

出版者

環境資源工学会

雑誌

環境資源工学 (ISSN:13486012)

巻号頁・発行日

vol.59, no.2, pp.73-80, 2012 (Released:2012-09-05)

参考文献数

13

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Moringa oleifera (M. oleifera) is one of the most widely spread Moringa species that grows quickly in the tropical belt. The objective of this study was to investigate the influence of the aqueous pH, initial turbidity of the synthetic kaolin turbid water, ionic strength, and humic substances on the efficiency of the M. oleifera coagulant. The experimental results showed that the coagulation efficiency was significantly enhanced by the presence of divalent cations such as Ca2+ or Mg2+, and slightly enhanced by lowering the aqueous pH from 9.0 to 4.0. It was also found that fulvic acid did not significantly affect the coagulation efficiency, while the initial turbidity and humic acid did. M. oleifera coagulant was effective for synthetic waters of an initial turbidity of 290 NTU. However, turbidity removal was not observed when the initial turbidity was lowered to 45 NTU. The presence of humic acid significantly increased the coagulant dosage required for turbidity removal. These obtained experimental observations were then used to discuss the influence of the water quality on the dominant coagulation mechanism.

著者

石川 明良 谷繁 岳志 田井 朝香 鈴木 祐麻 新苗 正和

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.134, no.9, pp.131-136, 2018-09-30 (Released:2018-09-27)

参考文献数

13

被引用文献数

4

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Chloride is one of the effective medium in which platinum group metals (PGMs) can be brought into a solution, thus chlorocomplexes are particularly important in the process chemistry of PGMs separations. Rh (III) chlorocomplexes are poorly extracted into organic solvents, which is due to the charge of the complex as well as those inert character in a solution, that is, formation of RhCl6-n(H2O)n(3-n) - (n=1-6) . The problem of solvent extraction of Rh from chloride solutions has not yet been solved and there is no effective industrial extractant for Rh. PGMs are traditionally separated from one another and the other metals by a complex series of selective precipitation techniques. These are generally inefficient in terms of the degree of separation achieved. Solvent extraction applied to refining process for PGMs offers several advantages over the traditional precipitation methods. Adding Sn (II) to a Rh (III) feed is a good procedure which can be used to make Rh react more easily to extraction, however, stripping of Rh from the loaded organic pahse is very difficult. In the present study, the extraction of Rh from hydrochloric acid solutions with tri-n-octylamine (TOA) and tri-octyl methyl ammonium chloride (TOMAC) were tested to clarify the effect of addition of Sn (II) on the extraction of Rh and stripping of Rh.

著者

鈴木 祐麻 Noor Diyana Binti Jamil 新苗 正和

出版者

環境資源工学会

雑誌

環境資源工学 (ISSN:13486012)

巻号頁・発行日

vol.60, no.3, pp.138-144, 2013 (Released:2013-10-15)

参考文献数

18

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The objective of this study was to investigate the disinfection efficiencies of E. coli and coliforms during the solar disinfection (SODIS) process with the presence of zero-valent iron and/or citric acid. The experimental results from a series of batch experiments showed that a treatment with neither sole UV-A (365 nm wavelength), zero-valent iron, nor citric acid effectively decreased the fraction of viable E. coli and coliforms under the experimental conditions investigated in this study. However, the simultaneous addition of zero-valent iron and citric acid during the UV-A illumination effectively decreased the fraction of viable E. coli and coliforms, meaning the co-existence of these three are required to effectively produce oxidants such as hydroxyl radical and ferryl ion. It was also demonstrated through field experiments that the technology proposed in this study can be easily implemented in our daily life using lemon juice rich in citric acid.

著者

新苗 正和 西垣 広大

出版者

一般社団法人 環境資源工学会

雑誌

環境資源工学 (ISSN:13486012)

巻号頁・発行日

vol.56, no.2, pp.64-67, 2009 (Released:2009-06-23)

参考文献数

7

被引用文献数

1 1

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The biodegradable chelating agents [S,S]-ethylenediaminedisuccinic acid (EDDS) and the low biodegradable chelating agent ethylenediaminetetraacetic acid (EDTA) were investigated for their removal efficiency of lead from soil by soil washing. In the soil washing tests, the removal efficiency of lead with EDTA was high in the wide pH range and the efficiency of lead removal with EDDS increased with increasing pH. However, EDDS has no effect on the removal of lead in the acidic region below pH 5.5. Acid contribution was predominant for the removal of lead with EDDS below pH 5.5 and the complexation between EDDS and lead were negligible. The reaction rates for extraction of lead with EDTA and EDDS were represented by the volume reaction model. The activation energies of these extraction reactions are over 55 kJ/mol and the apparent reaction rate constants are not affected by the stirring speeds, therefore it is considered that these extraction reactions are chemically controlled.