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in the presence of organic ligandsYoshida, Takahiro; Suzuki, Yoshinori*; Ozaki, Takuo; Onuki, Toshihiko; Francis, A. J.*
Proceedings of International Symposium on Radioecology and Environmental Dosimetry, p.296 - 300, 2004/03
The effects of organic ligands (citric acid, desferrioxamine B (DFO) and ethylenediaminetetraacetic acid (EDTA)) on Eu(III) adsorption by an aerobic bacterium were investigated. After incubation of 
with 2 
M Eu(III) without organic ligands in a 0.1 M NaCl solution containing 3.9 mg
/L biomass for 1 hour, over 90% Eu(III) was adsorbed on the bacterial cells at pH 4 - 7. Eu(III) adsorption by bacterial cells was depleted at pH 4 - 7 when equimolar EDTA was present, while citric acid and DFO showed less effect on the depletion of Eu(III) adsorption. X-ray photoelectron spectroscopy (XPS) indicated that the adsorbed Eu(III) on cells was covalently bound to carboxyl and/or hydroxyl functional groups of the cell surface. These results suggest that carboxyl and/or hydroxyl functional groups of cell surface show a higher affinity with Eu(III) than citric acid and DFO and have the potential to prevent migration of Eu-organic ligands complexes with low stability constants in environments.
Otosaka, Shigeyoshi; Aramaki, Takafumi*; Suzuki, Takashi; Kobayashi, Takuya; Ito, Toshimichi; Togawa, Orihiko; Chaykovskaya, E. L.*; Dunaev, A. L.*; Karasev, E. V.*; Novichkov, V. P.*; et al.
Proceedings of International Symposium on Radioecology and Environmental Dosimetry, p.390 - 395, 2003/10
Seabed sediments were collected at 22 stations in the Japan Sea, and anthropogenic radionuclides were measured in order to understand distributions and accumulation processes of these materials. Averaged concentrations of 
Cs in sediment in the Japan Basin and the Yamato Basin were 1.0 Bq/kg and 1.0 Bq/kg, respectively. Although there was no significant difference in mean Cs concentration between the Japan Basin and the Yamato Basin, distributions of radionuclides in these 2 basins showed different features. In the Japan Basin, the spatial variation of concentration of radionuclides was smaller than that at the Yamato Basin. At most stations in the Yamato Basin, significant concentrations of radionuclides were not detected, but remarkable large activities were observed at several stations in the Yamato Basin. For all radionuclides, the highest concentration was observed in the southeastern margin of the Yamato Basin. These results would suggest that there were different accumulation processes of radionuclides between the Japan Basin and the Yamato Basin.
Takeyasu, Masanori; Nakano, Masanao; Takeishi, Minoru
Proceedings of International Symposium on Radioecology and Environmental Dosimetry, p.511 - 515, 2003/10
SIERRA-II has been developed in JNC, to estimate the spatially detailed environmental dose near the nuclear facility in an emergency situation. The performance of SIERRA-II was examined by using the observed data of ambient dose rate around the Tokai Reprocessing Plant(TRP) during the discharges of 85Kr to the atmosphere under the normal operation of the TRP.
Koarashi, Jun; Iida, Takao*; Moriizumi, Jun*; Asano, Tomohiro
Proceedings of International Symposium on Radioecology and Environmental Dosimetry, p.92 - 99, 2003/10
Soil organic matter (SOM) is a significant carbon reservoir in terrestrial ecosystems. Therefore, knowledge of SOM dynamics is essential for better understanding not only the global carbon cycle but also the environmental behabior of additional 14C produced by the nuclear power industry. In this study, carbon isotope compositions were determiend for chemically fractionated SOM and soil respiration in an urban forest, to investigate the formation, storage and decomposition of SOM.
Kato, Tomoko; Suzuki, Yuji*; Makino, Hitoshi; Uchida, Masahiro
Proceedings of International Symposium on Radioecology and Environmental Dosimetry, p.465 - 472, 2003/10
Considering a wide range of Japanese geological environments in generic context, some biosphere models were developed using an approach consistent with the BIOMASS Methodology. Moreover, sensitivity analysis for the biosphere models was performed to evaluate and understand the relative importance of parameters.
Ito, Toshimichi; Aramaki, Takafumi*; Otosaka, Shigeyoshi; Suzuki, Takashi; Togawa, Orihiko; Kobayashi, Takuya; Senju, Tomoharu*; Chaykovskaya, E. L.*; Lishavskaya, T. S.*; Karasev, E. V.*; et al.
Proceedings of International Symposium on Radioecology and Environmental Dosimetry, p.396 - 401, 2003/10
no abstracts in English
Nakano, Masanao
Proceedings of International Symposium on Radioecology and Environmental Dosimetry, 505- Pages, 2003/10
None
Tanaka, Tadao; Mukai, Masayuki; Maeda, Toshikatsu; Munakata, Masahiro; Matsumoto, Junko; Ogawa, Hiromichi; Bamba, Tsunetaka*; Wang, Z.*; Yang, Y.*; Zhao, Y.*
Proceedings of International Symposium on Radioecology and Environmental Dosimetry, p.179 - 184, 2003/00
Migration behaviors of stable strontium element and radioactive nuclide strontium 90 in natural aquifer were studied by a field test, which was performed in the aquifer loess zone at 30 m under the ground surface of the field test site of China Institute for Radiation Protection. The migration behavior of stable strontium was a little different from that of 
Sr. The difference was evaluated by applying the distribution coefficient considering Sr and coexistent ion concentrations. Migration behavior of radionuclide in natural environment has been generally demonstrated on field tests without radioactive tracers and/or large-scale column tests with radioactive tracers. Such tests seem to be valuable to improve reliability of the migratory evaluation.
Atarashi-Andoh, Mariko; Amano, Hikaru
Proceedings of International Symposium on Radioecology and Environmental Dosimetry, p.484 - 487, 2003/00
C-14 is one of the radionuclides released to the environment with routine operations of nuclear facilities. A dynamic compartment model was developed for estimation of C-14 behavior in paddy field. It calculates carbon transfer among air, rice, irrigation water and soil. The calculation was carried out using MOGRA: a generic analysis code of dynamic compartment model.
Kobayashi, Takuya; Nagai, Haruyasu; Chino, Masamichi; Togawa, Orihiko
Proceedings of International Symposium on Radioecology and Environmental Dosimetry, p.500 - 504, 2003/00
The possibility of radionuclide release to the environment is on the increase due to a growth of nuclear facilities in Asia, military problems, nuclear terrorism, etc. The released radionuclides circulate among the atmospheric, oceanic and terrestrial environment, influencing human and natural environment through complex processes. In order to reduce the damage from these pollutants, it is necessary to estimate their migration behavior in detail. A software system SPEEDI-MP (SPEEDI Multi-model Package) is under development to resolve such environmental problems by simulating the 'inclusive and successive' behavior of pollutants in the atmospheric, oceanic and terrestrial environment. As code verification, the system has been applied to a hypothetical accident of a nuclear submarine if it sinks in an offshore region around Japan. The predicted results are examined, and the applicability and validity of the system are discussed.