Chemical implication of the partition coefficient of 137 Cs between the suspended and dissolved phases in natural water.

Autor: Hirose K; Laboratory for Environmental Research at Mount Fuji, Shujyuku-ku, Tokyo, 169-0072, Japan. Electronic address: hirose45037@mail2.acccsnet.ne.jp., Onda Y; Center for Research in Isotopes and Environmental Dynamics, University of Tsukuba, Tsukuba, Ibaraki, 305-0006, Japan., Tsukada H; Institute of Environmental Radioactivity, Fukushima University, Fukushima-City, Fukushima, 960-1296, Japan., Hiroyama Y; Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Kioi-Cho, Chiyoda-ku, Tokyo, 102-8554, Japan., Okada Y; Atomic Energy Laboratory, Tokyo City University, Ozenji 971, Asao-ku, Kawasaki, 215-0031, Japan., Kikawada Y; Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, Kioi-Cho, Chiyoda-ku, Tokyo, 102-8554, Japan.
Jazyk: angličtina
Zdroj: Journal of environmental radioactivity [J Environ Radioact] 2024 Sep; Vol. 278, pp. 107486. Date of Electronic Publication: 2024 Jun 26.
DOI: 10.1016/j.jenvrad.2024.107486
Abstrakt: After the Fukushima Daiichi nuclear power plant accident, the terrestrial environment became severely contaminated with radiocesium. Consequently, the river and lake water in the Fukushima area exhibited high radiocesium levels, which declined subsequently. The partition coefficient of 137 Cs between the suspended sediment (SS) and dissolved phases, K d , was introduced to better understand the dynamic behavior of 137 Cs in different systems. However, the K d values in river water, ranging from 2 × 10 4 to 7 × 10 6  L kg -1 , showed large spatiotemporal variability. Therefore, the factors controlling the 137 Cs partition coefficient in natural water systems should be identified. Herein, we introduce a chemical model to explain the variability in 137 Cs K d in natural water systems. The chemical model includes the complexation of Cs + with mineral and organic binding sites in SS, metal exchange reactions, and the presence of colloidal species. The application of the chemical model to natural water systems revealed that Cs + is strongly associated with binding sites in SS, and a major chemical interaction between 137 Cs and the binding sites in SS is the isotope exchange reaction between stable Cs and 137 Cs, rather than metal exchange reactions with other metal ions such as potassium ions. To explain the effect of the SS concentration on K d , the presence of colloidal 137 Cs passing through a filter is significant as the dominant dissolved species of 137 Cs in river water. These results suggest that a better understanding of stable Cs dissolved in natural water is important for discerning the geochemical and ecological behaviors of 137 Cs in natural water.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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