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Battulga, B.; Nakanishi, Takahiro; Atarashi-Andoh, Mariko; Otosaka, Shigeyoshi*; Koarashi, Jun
Environmental Science and Pollution Research, 31, p.60080 - 60092, 2024/10
A ubiquitous distribution of plastic debris has been reported in aquatic and terrestrial environments; however, the interactions between plastics and radionuclides and the radioactivity of environmental plastics remain largely unknown. Here, we characterize biofilms developing on the surface of plastic debris to explore the role of plastic-associated biofilms as an interaction medium between plastics and radiocesium (
Cs) in the environment. Biofilm samples were extracted from plastics (1-50 mm in size) collected from two contrasting coastal areas in Japan. The radioactivity of plastics was estimated based on the Cs activity concentration of the biofilms and compared seasonally with surrounding environmental samples (i.e., sediment and sand). Cs traces were detected in biofilms with activity concentrations of 21-1300 Bq kg
biofilm (dry weight), corresponding to 0.04-4.5 Bq kg plastic (dry weight). Our results reveal the interaction between Cs and plastics and provide evidence that organic and mineral components in biofilms are essential in Cs retention in environmental plastics.
Nara, Yoshitaka*; Kuwatani, Ryuta*; Kono, Masanori*; Sato, Toshinori; Kashiwaya, Koki*
Zairyo, 67(7), p.730 - 737, 2018/07
Information of confining ability of rock is important for the geological disposal of radioactive wastes. To maintain or improve the confining ability of rocks, it is important to seal pores and cracks. In this study, we investigated the precipitation of minerals on the rock surface. As rock samples, we used Berea sandstone and Toki granite in this study. It was shown that precipitation occurred on the surface of rock specimens kept in calcium hydroxide solution for 1 month if the concentration was high. Specifically, if the concentration of calcium hydroxide solution was higher than 300 mg/l, the precipitation occurred obviously. After keeping rock specimens in calcium hydroxide solution, the weight of the rock samples increased and the concentration of calcium ion decreased by the precipitation. It is considered that the calcium ion in water was used for the precipitation on rock surfaces. Since the precipitation has been recognized for rock surfaces, it is possible to seal pores and cracks in rocks. Therefore, it is also possible to keep or decrease the permeability of rocks by the precipitation of calcium compounds.
Kasahara, Mikio*; Ma, C.-J.*; Okumura, Motonori*; Kojima, Takuji; Hakoda, Teruyuki; Taguchi, Mitsumasa; Sakai, Takuro; Ohara, Yoshihiro
JAERI-Review 2004-025, TIARA Annual Report 2003, p.256 - 258, 2004/11
As the source of Asian dust particles, the sands at four different desert areas in China were to be the target of bulk and single analyses by means of PIXE and micro-PIXE analyses, respectively. The physical properties of desert sands like morphology, color, and size were basically determined. Also the chemical characteristics of bulk sands of each desert were specified as the relative elemental mass. The elemental maps and spectra for individual sands allow us to understand the nature of individual sands. Consequently, the physicochemical properties of desert sands obtained from this study can be helpful to understand what kinds of man-made pollutants and sea-salts are incorporated into natural Asian dust particles.
Tanaka, Tadao; Nagao, Seiya; Sakamoto, Yoshiaki; Ogawa, Hiromichi
Journal of Nuclear Science and Technology, 39(Suppl.3), p.524 - 527, 2002/11
Influence of humic acid on the sorption of Pu onto a coastal sand, which does not sorb humic acid, and an ando soil, which sorbs humic acid very well, was examined with respect to molecular sizes of humic acid. Sorption affinity of Pu for the coastal sand decreased with increasing humic acid concentration. As to the ando soil, the sorption affinity of Pu in the presence of humic acid was larger than that in the absence of humic acid, in low humic acid concentration range. These results suggest that apparent sorption affinity of Pu on the soils is dependent on the complexation ability with humic acid and the sorption affinity of the resulting humic complexes. Concentration profiles of Pu in each size fraction of solution before and after the sorption experiment were obtained by ultrafiltration technique. It was found that the complexation and sorption properties of humic acid are dependent on its molecular size and the important molecular size relating to the complexation and sorption properties tends to shift into smaller size ranges with increasing humic acid concentration.
Terada, Hiroaki; Ueda, Hiromasa*; Wang, Z.*
Proceedings of 7th International Joint Seminar on the Regional Deposition Processes in the Atmosphere, p.115 - 122, 2001/11
The neutralization of acid rain by yellow-sand in East Asia was investigated numerically by an Air Quality Prediction Modeling System (AQPMS). AQPMS consists of advection, diffusion, dry and wet deposition, gas-phase chemistry and the liquid-phase chemistry. Different from the previous ones for Sahara and Australian deserts, a new deflation module of the yellow-sand was designed here, and this module was linked to the AQPMS. Firstly, for model validation, predicted various values were compared with measured values at atmospheric monitoring stations, and a reasonable agreement was obtained for April 1995. Secondly, a sensitivity experiment about chemical effects of yellow-sand was made and the result of it exhibited a strong neutralization of the precipitation by the yellow-sand. The monthly mean pH values in the northern China showed a remarkable increase of 0.6-1.8 by neutralization effect of the yellow-sand, while the increases in the southern China were less than 0.1. Even in Korea and Japan the yellow-sand caused the increase of the pH value of rain by 0.1-0.2.
Maekawa, Fujio; Von-Moellendorff, U.*; Wilson, P. P. H.*; Wada, Masayuki*; Ikeda, Yujiro
Reactor Dosimetry: Radiation Metrology and Assessment (ASTM STP 1398), p.417 - 424, 2001/00
no abstracts in English
Maekawa, Fujio; Wada, Masayuki*; Von-Moellendorff, U.*; Wilson, P. P. H.*; Ikeda, Yujiro
Fusion Engineering and Design, 51-52(Part.B), p.815 - 820, 2000/11
Times Cited Count：4 Percentile：31.80(Nuclear Science & Technology)no abstracts in English
Uno, Yoshitomo; Zaman, M. R.*; Ikeda, Yujiro
Journal of Nuclear Science and Technology, 37(Suppl.1), p.545 - 549, 2000/03
no abstracts in English
Maekawa, Fujio; U.Moellendorff*; P.Wilson*; Ikeda, Yujiro
Fusion Technology, 36(2), p.165 - 172, 1999/09
no abstracts in English
Takeda, Seiji; Kimura, Hideo; Moltyaner, G. L.*; Klukas, M. H.*
Proceedings of 7th International Conference on Radioactive Waste Management and Environmental Remediation (ICEM '99) (CD-ROM), 7 Pages, 1999/00
no abstracts in English
Sakamoto, Yukio; Tanaka, Susumu; ; Nakane, Yoshihiro; Meigo, Shinichiro; Takada, Hiroshi; Tanaka, Shunichi; Takada, M.*; Kurosawa, Tadahiro*; Nakamura, Takashi*; et al.
Genshikaku Kenkyu, 41(3), p.95 - 99, 1996/06
no abstracts in English
Nagao, Seiya; Tanaka, Tadao; Sakamoto, Yoshiaki;
Radiochimica Acta, 74, p.245 - 249, 1996/00
no abstracts in English
Tachibana, Mitsuo; ; Myodo, Masato; Hatakeyama, Mutsuo;
The 3rd JSME/ASME Joint Int. Conf. on Nuclear Engineering (ICONE),Vol. 4, 0, p.1811 - 1815, 1995/00
no abstracts in English
Kinouchi, Nobuyuki; Kato, Shohei
Kankyo Eisei Kogaku Kenkyu, 8(3), p.133 - 138, 1994/00
no abstracts in English
Kato, Shohei; Yanase, Yoshiaki
JAERI-M 93-113, 17 Pages, 1993/05
no abstracts in English
Journal of Physical Chemistry, 97(9), p.1832 - 1834, 1993/00
Times Cited Count：10 Percentile：40.61(Chemistry, Physical)no abstracts in English
; ; ; ; ; ; ;
JAERI-M 86-166, 237 Pages, 1986/12
no abstracts in English
Kumazawa, Shigeru;
Oyo Tokeigaku, 15(1), p.1 - 14, 1986/00
no abstracts in English
; ; Yamamoto, Tadatoshi; Wadachi, Yoshiki
Hoken Butsuri, 18, p.11 - 16, 1983/00
no abstracts in English
Sakurai, Kiyoshi
Nuclear Instruments and Methods, 213(2-3), p.359 - 371, 1983/00
no abstracts in English
