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Journal Articles

Characterization and thermodynamic study of humic acid in deep groundwater at Horonobe, Hokkaido, Japan

Kimuro, Shingo*; Kirishima, Akira*; Nagao, Seiya*; Saito, Takumi*; Amano, Yuki; Miyakawa, Kazuya; Akiyama, Daisuke*; Sato, Nobuaki*

Journal of Nuclear Science and Technology, 55(5), p.503 - 515, 2018/05

 Times Cited Count:2 Percentile:16.17(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Extraction of groundwater humic substances and characterization by synthetic resin

Ueda, Masato; Sakamoto, Yoshiaki*

Genshiryoku Bakkuendo Kenkyu, 12(1-2), p.31 - 39, 2006/03

no abstracts in English

Journal Articles

Influence of humic substances on the $$^{63}$$Ni migration through crushed rock media

Tanaka, Tadao; Sakamoto, Yoshiaki; Mukai, Masayuki; Maeda, Toshikatsu; Nakayama, Shinichi

Radiochimica Acta, 92(9-11), p.725 - 729, 2004/12

 Times Cited Count:1 Percentile:88.5(Chemistry, Inorganic & Nuclear)

Migration experiments of $$^{63}$$Ni for crushed rocks, granite and tuff, were performed under the coexistent condition with a humic acid and a fulvic acid of 0-30 mg/l in concentration, which are Nordic humic substances supplied from International Humic Substance Society. Migration experiments of Ni had been performed by a column system, to investigate migration behavior of Ni through a column packed crushed rock. The Ni concentration in the effluent passed through the column was corresponding to the fractional percentage of Ni complexing with humic substance in influent solution. This result suggests that the Ni complexing with humic substance in influent solution was flowed out from the column without any effective interactions with the rock media. The migration behavior of Ni could be expressed by a migration model taking account of the complexation kinetics of Ni with humic substance in the aqueous phase.

Journal Articles

Migration models of neptunium and americium in groundwater under the present condition of humic substances

Tanaka, Tadao; Sakamoto, Yoshiaki; Sawada, Hiroshi; Ogawa, Hiromichi

JAERI-Conf 2003-010, p.134 - 141, 2003/09

We have performed migration experiments of Np(V) and Am(III) for crushed granite, under the coexistent condition with humic acid substance. As for Np, the periodical concentration changes in the breakthrough curve and the migration velocity of Np passed through the column were not affected by the coexistence of the humic substance. As for Am, on the other hand, the periodical concentration changes in the breakthrough curve were affected by the humic substance concentration. The migration behavior of Am passed through the present column system could be expressed by a migration model taking account of the non-equilibrium state.

Journal Articles

Effect of humic acid on the bioavailability of radionuclides to rice plants

Ozaki, Takuo; Ambe, Shizuko*; Abe, Tomoko*; Francis, A. J.

Analytical and Bioanalytical Chemistry, 375(4), p.505 - 510, 2003/02

 Times Cited Count:6 Percentile:77(Biochemical Research Methods)

no abstracts in English

Journal Articles

In situ ATR-FTIR spectroscopy for functional groups of humic substances complexing with metal ions

Tanaka, Tadao; Sakamoto, Yoshiaki; Ogawa, Hiromichi

Genshiryoku Bakkuendo Kenkyu, 9(1), p.29 - 34, 2002/09

To obtain structural information on functional groups of humic substances complexing with metal ions, infrared (IR) spectral analysis of the humic substances dissolving in aqueous solutions has been studied by ATR (Attenuated Total Reflection) method. By using the ATR method, IR spectral shifts of humic substance due to complexation with metal ions were observed. The observation provided with information on complexation kinetics, and on characteristics of functional groups depending on solvent properties, such as pH and solute concentrations. These information was difficult to be obtained by conventional FTIR spectroscopy using powdered humic substances. The obtained results show that IR spectral shifts on the functional groups of the humic substances complexed with metal ions could be possibly characterized ${it in situ}$ by using the ATR-FTIR spectroscopy.

Journal Articles

Fluorescence quenching studies of Eu-humic complexes by three-dimensional excitation emission matrix spectroscopy

Nagao, Seiya; Aoyama, Masakazu*; Watanabe, Akira*; Nakaguchi, Yuzuru*; Ogawa, Hiromichi

Analytical Sciences (CD-ROM), 17(Suppl.), p.1585 - 1588, 2002/03

no abstracts in English

Journal Articles

Degradation characteristics of humic acid during photo-Fenton processes

Fukushima, Masami*; Tatsumi, Kenji*; Nagao, Seiya

Environmental Science & Technology, 35(18), p.3683 - 3690, 2001/09

 Times Cited Count:105 Percentile:7.67(Engineering, Environmental)

no abstracts in English

Journal Articles

Exisitence forms of Am(III) in the presence of humic substances in saline groundwater at pH 7-10

Nagao, Seiya; Nakaguchi, Yuzuru*; Suzuki, Yasuhiro*; Hiraki, Keizo*; Fujitake, Nobuhide*; Ogawa, Hiromichi

Proceedings of International Conference on the Biogeochemistry of Trace Elements (ICOBTE2001), P. 666, 2001/00

no abstracts in English

Journal Articles

The Migration behavior of Np(V) in sandy soil and granite media in the pressence of humic substances

Sakamoto, Yoshiaki; Nagao, Seiya; Ogawa, Hiromichi; Rao, R. R.*

Radiochimica Acta, 88(9-11), p.651 - 656, 2000/09

 Times Cited Count:10 Percentile:38.57(Chemistry, Inorganic & Nuclear)

no abstracts in English

JAEA Reports

Experimental study of gas generation by microorganism

Mine, Tatsuya*; ;

JNC-TN8430 2000-010, 27 Pages, 2000/07

JNC-TN8430-2000-010.pdf:0.72MB

In the geological disposal system of the radioactive wastes, gas generation by microorganism could be significant for the assessment of this system, because organic material included in groundwater, buffer material and wastes might serve as carbon sources for microorganisms. In this study, gas generation tests using microorganisms were carried out under anaerobic condition. The amount of methane and carbon dioxide that were generated by activity of Methane Producing Bacteria (MPB) were measured with humic acid, acetic acid and cellulose as carbon sources. The results showed that methane was not generated from humic acid by activity of MPB. However, in the case of using acetic acid and cellulose, methane was generated, but at high pH condition (pH=10), the amount of generated methane was lower than at low pH (pH=7). It was not clear whether the pH would affect the amount of generated carbon dioxide.

JAEA Reports

Influence of naturally-occurring heterogeneous complex-forming materials on the migration behavior of actinides in the geosphere (III)

Tochiyama, Osamu*

JNC-TJ8400 2000-044, 53 Pages, 2000/02

JNC-TJ8400-2000-044.pdf:1.41MB

To estimate the polyelectrolyte effect and the effect of the heterogeneous composition of humic acids, the complex formation constants of Eu(III) and Ca(II) with Aldrich humic acid and polyacrylic acid were obtained, for Eu(10$$^{-8}$$ to 10$$^{-5}$$ M) by solvent extraction with TTA and TBP in xylene, for Ca (10$$^{-10}$$M) with TTA and TOPO in cyclohexane and for Ca(10$$^{-4}$$M) by using ion-selective electrode. By defining the apparent formation as $$beta_{alpha}$$ = [MR$$_{m}$$]/([M][R]), where [R] denotes the concentration of dissociated functional group, [M] and [MR$$_{m}$$] denote the concentration of free and bound metal ion and pcH is defined as-log[H], the values of log$$beta_{alpha}$$ have been obtained at pcH 4.8 - 5.5 in 0.1 - 1.0M NaClO$$_{4}$$ and NaCl. Log$$beta_{alpha}$$ of Eu-humate varied from 5.0 to 9.3 and that of Ca-humate from 2.0 to 3.4..For both humate and polyacrylate, log$$beta_{alpha}$$ increased with pcH or with the degree of dissociation. The increase in the ionic strength O.1 to 1.0 M decreased the log$$beta_{alpha}$$, the decrease in log$$beta_{alpha}$$ of Eu(III)-humate is 1.6, that of Eu(III), polyacrylate 0.7, that of Ca(II)-humate 1.9 and that of Ca(II)-polyacrylate 1.2. While the increase in the metal ion produced no effect on log$$beta_{alpha}$$ of polyacrylate, log$$beta_{alpha}$$ of humate decreased. Depending on the concentration of Eu(III), the coexistence of Ca(II) reduced log $$beta_{alpha}$$ of humate by 0 to 0.8. The dependence of log$$beta_{alpha}$$ of humate on the metal ion concentration suggests the coexistence of strong and weak binding sites in the hmnic acid.

JAEA Reports

Certification of reliability of nuclide migration data

Ueda, Shinzo*; *; *; *

JNC-TJ8400 2000-002, 316 Pages, 2000/02

JNC-TJ8400-2000-002.pdf:14.28MB

Japan Nuclear Cycle Development Institute (JNC) have been setting migration parameters and developing its database for the 2nd Progress Report of HLW Geological Disposal (H12 Report). In this study, experimentswere carried out to certify the reliability of parameters and scenario, and examination was carried out to survey procedures of quality management. The main contents are as follows. (1)Data acquisition for certification of migration parameters. The effect of NH$$_{3}$$ complex of Pd on distribution coefficients (Kd) of Pd on both bentonite and rocks, and the effect of sulfate and carbonate complexes of Am on Kds of Am on bentonite are investigated. Kds of Pd depended on NH$$_{4}^{+}$$ concentration in aqueous. The dependence varied with pH. Effects of sulfate and carbonate complexes on Kds of Am were not remarkable. Apparent diffusivities of Cs in bentonite saturated by saline water were measured. It was confirmed that the apparent diffusivities of Cs in saline water were similar to those in pure water. (2)Evaluation of colloidal effect on nuclide migration. An evaluation of validity of analytical model (Hwang's model) for nuclide migration under existence of colloids and investigation of characterization of colloids in groundwater were carried out. As the results, it was indicated that the Hwang's model was appropriate, and it was found that samplingtechnique influenced concentration and size distribution of colloids. (3)Influence of organic substances on solubility. Solubility of Th was measured under the condition with humic acid and carbonate. It increased roughly in proportion to the concentration of humic acid. And it was remarkably high under the condition with carbonate. It was confirmed that Th solubility data set in H12 report was conservative, even though humic acid existed in groundwater. (4)Use of Mechanistic Models for Safety Assessment. The integrated sorption/diffusion model has been used to calculate K$$_{d}$$, D$$_{a}$$ and D$$_{e}$$ values ...

JAEA Reports

An Estimation of influence of humic acid and organic matter originated from bentonite on samarium solubility

*; Sato, Haruo; *

JNC-TN8400 99-059, 59 Pages, 1999/10

JNC-TN8400-99-059.pdf:1.54MB

Organic acids in groundwater are considered to form complexes and increase the solubility of radionuclides released from vitrified waste in a high-level radioactive waste (HLW) repository. To ivestigate whether the solubility of samarium (Sm) is influenced by organic substances, we measured Sm solubility in the presence of different organic substances and compared those values with results from thermodynamic predictions. Humic acid (Aldrich) is commercially available and soluble organic matter originated from bentonite were used as organic substances in this study. Consequently, the solubility of Sm showed a tendency to apparently increase with icreasing the concentration of humic acid, but in the presence of carbonate, thermodynamic predictions suggested that the dominant species are carbonate complexes and that the effect of organic substances are less than that of carbonate. Based on total organic carbon (TOC), the increase of Sm solubility measured with humic acid (Aldrich) was more significant than that in the case with soluble organic matter originated from bentonite. Since bentonite is presumed to include also simple organic matters of which stability constant for forming complexes is low, the effect of soluble organic matter originated from bentonite on the solubility of Sm is eonsidered to be less effective than that of humic acid (Aldrieh). Experimental values were compared with model prediction, propsed by Kim, based on data measured in a low pH region. Tentatively we calculated the increase in Sm solubility assuming complexation with humic acid. Trial calculations were carried out on the premise that the complexation reaction of metal ion with humic acid is based on neutralization process by 1-1 complexation. In this process, it was assumed that one metal ion coordinates with one unit of complexation sites which number of proton exchange sites is equal to ionic charge. Consequently, Kim's model indicated that carbonate complexes should be dominant ...

Journal Articles

Modeling of neptunium(V),plutonium(IV) and americium(III) sorption on soils in the presence of humic acid

Tanaka, Tadao; Sakamoto, Yoshiaki; Muraoka, Susumu

JAERI-Conf 99-004, p.662 - 673, 1999/03

no abstracts in English

Journal Articles

Speciation of europium(III) sorbed on a montmorillonite surface in the presence of polycarboxylic acid by laser-induced fluorescence spectroscopy

Takahashi, Yoshio*; Kimura, Takaumi; Kato, Yoshiharu; Minai, Yoshitaka*

Environmental Science & Technology, 33(22), p.4016 - 4021, 1999/00

 Times Cited Count:40 Percentile:24.87(Engineering, Environmental)

no abstracts in English

Journal Articles

Laser-induced fluorescence study on the interaction of Eu(III) with polycarboxylates

Takahashi, Yoshio*; Kimura, Takaumi; Kato, Yoshiharu; *; *; *

Journal of Radioanalytical and Nuclear Chemistry, 239(2), p.335 - 340, 1999/00

 Times Cited Count:15 Percentile:24.36(Chemistry, Analytical)

no abstracts in English

JAEA Reports

None

PNC-TJ1601 98-003, 57 Pages, 1998/03

PNC-TJ1601-98-003.pdf:1.76MB

None

JAEA Reports

None

*; *; Kamoshida, Mamoru*; *

PNC-TJ1124 98-002, 48 Pages, 1998/02

PNC-TJ1124-98-002.pdf:1.53MB

None

Journal Articles

Characteristics of the fluorescent substances in the Yodo river system by three-dimensional excitation emission matrix spectroscopy

Suzuki, Yasuhiro*; Nakaguchi, Yuzuru*; Hiraki, Keizo*; Nagao, Seiya; *; *

Chikyu Kagaku, 32, p.21 - 30, 1998/00

no abstracts in English

54 (Records 1-20 displayed on this page)