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Environmental conditions for insoluble Tc formation in ponding water above a paddy field
https://repo.qst.go.jp/records/68598
https://repo.qst.go.jp/records/6859856a750a8-5221-4ad6-b7b6-4fb92b7a0c23
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2006-07-21 | |||||
| タイトル | ||||||
| タイトル | Environmental conditions for insoluble Tc formation in ponding water above a paddy field | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Ishii, Nobuyoshi
× Ishii, Nobuyoshi× Koiso, Hiroyuki× Takeda, Hiroshi× Uchida, Shigeo× 石井 伸昌× 小礒 寛之× 武田 洋× 内田 滋夫 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Technetium-99 is a radioactive contaminant in marine and terrestrial environments. Under oxic conditions, it is present as the pertechnetate anion [Tc(VII)O4-], which is soluble and mobile in the environment. In paddy fields in Japan, the accumulation of Tc in the 20-cm plow layer was observed (Tagami and Uchida 2002). Since paddy fields are flooded during the planting season, reductive conditions develop in the plowed layer. Under reductive conditions, Tc is transformed from Tc(VII) O4- to Tc(IV) species. Tc(IV) species generally are insoluble and immobile in the environment, and thus Tc(IV) could accumulate in the plowed layer. Recently, it was found that gram-negative-bacteria were responsible for the formation of insoluble Tc in the ponding water of flooded paddy fields (Ishii and Uchida 2005). This insolubilization would be one of the factors of the Tc accumulation in the plowed layer because bacteria sink into the plowed layers due to their own weight over time. However, little information is available for environmental conditions of Tc insolubilizing by the bacteria. In this study, optimum oxic conditions for the insolubilization were determined. |
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| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | 18th World Congress of Soil Science | |||||
| 発表年月日 | ||||||
| 日付 | 2006-07-15 | |||||
| 日付タイプ | Issued | |||||
