RICE UPTAKE AND LEACHING OF 99TC IN DIFFERENT PADDY SOILS CONTAMINATED ACCORDING TO TWO CONTRASTING SCENARIOS
| Autor: | Dong-Kwon Keum, Kwang-Muk Lim, Byung-Ho Kim, Yong-Ho Choi, In Jun |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Radiation
business.product_category Health Toxicology and Mutagenesis Public Health Environmental and Occupational Health Sorption Contamination Plough Agronomy Lysimeter Environmental science Radiology Nuclear Medicine and imaging Transplanting Brown rice Leaching (agriculture) business Deposition (chemistry) |
| Zdroj: | Journal of Radiation Protection and Research. 40:231-243 |
| ISSN: | 2466-2461 2508-1888 |
| Popis: | Four different paddy soils collected around the Gyeongju nuclear site were treated with 99TcO4− solution under the assumption of two contrasting contamination scenarios. Scenario I (SN-I) is for a pre-transplanting deposition of 99Tc followed by plowing, whereas SN-II is for its deposition onto the water surface shortly after transplanting. Rice plants were grown in lysimeters in a greenhouse. Plant uptake of 99Tc was quantified with the TFarea (m2·kg−1-dry). The SN-II TFarea values for straws and brown rice, having been generally higher than the SN-I values, were within the ranges of 6.9x10−3~4.1x10−2 and 5.2x10−6~7.3x10−5, respectively. Sorption onto clay seems to have decreased 99Tc uptake in SN-I, whereas it may have had an insignificant effect in SN-II. A phenomenon characteristic of submerged paddy soil, i.e., the development of a thin oxic surface layer may have greatly affected the rice uptake of SN-II 99Tc. The surface-water concentrations of 99Tc were much higher in SN-II than in SN-I. For the percolating water, however, the opposite was generally true. At most 1.3% of the applied 99Tc were leached through such percolation. The use of empirical deposition time-dependent TFarea values was considered desirable in assessing the radiological impact of a growing-season deposition of 99Tc onto paddy fields. |
| Databáze: | OpenAIRE |
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