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Saito, Takumi; Terashima, Motoki; Aoyagi, Noboru; Nagao, Seiya*; Fujitake, Nobuhide*; Onuki, Toshihiko
Environmental Science; Processes & Impacts, 17(8), p.1386 - 1395, 2015/08
Times Cited Count:9 Percentile:32.12(Chemistry, Analytical)The deep groundwater HSs were different from surface HSs, having high aliphaticities, sulfur contents, and small molecular sizes. The amounts of their acidic functional groups were comparable to or slightly larger than those of surface HSs; however, the magnitude of Cu binding to the deep groundwater HSs was smaller. The NICA-Donnan model attributed this to the binding of Cu to chemically homogeneous carboxylic-type sites via mono-dentate coordination at relatively low pH. The binding mode tended to shift to multi-dentate coordination with carboxylic-type and probably more heterogeneous alcoholic hydroxide-type groups at higher pH. This study shows the particularity of the deep groundwater HSs in terms of their physicochemical and ion-binding properties, compared with surface HSs.
Terashima, Motoki; Nagao, Seiya*; Iwatsuki, Teruki; Fujitake, Nobuhide*; Seida, Yoshimi*; Iijima, Kazuki; Yoshikawa, Hideki
Journal of Nuclear Science and Technology, 49(8), p.804 - 815, 2012/08
Times Cited Count:12 Percentile:66.29(Nuclear Science & Technology)Nagao, Seiya*; Sakamoto, Yoshiaki; Rao, R. R.*; Fujitake, Nobuhide*
Humic Substances Research, 5-6(1), p.9 - 17, 2009/00
Sorption behavior of Np(V) onto sandy materials (sand, tuffaceous sand and sandy rock) was studied in the absence and presence of humic substances (HS) using a batch method at pH 5-6 and ionic strength of 0.01M. The effects of shallow land groundwater HS on the Np(V) sorption depend on the mineralogical components of sandy materials. The distribution coefficient (Kd) of Np(V) increased in the presence of HS. The Kd values were in the order of sandtuffaceous sandsandy rock samples. The Np(V) sorption in the presence of HS with different origin for the sandy rock sample was divided into two groups. The Kd values were positively correlated with aliphatic carbon contents of the lake and the shallow groundwater HS, except for the deep saline groundwater HS. These results indicates that the characteristics of the sandy materials and groundwater HS are important factors determining the Np(V) sorption because of the presence of Np(V)-bound HS.
Nagao, Seiya*; Fujitake, Nobuhide*; Kodama, Hideki*; Matsunaga, Takeshi; Yamazawa, Hiromi
Journal of Radioanalytical and Nuclear Chemistry, 255(3), p.459 - 464, 2003/03
Times Cited Count:8 Percentile:49.75(Chemistry, Analytical)no abstracts in English
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
Nagao, Seiya; Nakaguchi, Yuzuru*; Fujitake, Nobuhide*; Ogawa, Hiromichi
Proceedings of 10th International Meeting of the International Humic Substances Society (IHSS10), p.1143 - 1146, 2000/07
no abstracts in English
Nagao, Seiya; Matsunaga, Takeshi; Fujitake, Nobuhide*; Amano, Hikaru
Proceedings of the International Workshop on Distribution and Speciation of Radionuclides in the Environment, p.162 - 168, 2000/00
no abstracts in English