| Autor: |
Forsberg, Sverker, Strandmark, Mona |
| Předmět: |
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| Zdroj: |
Water, Air & Soil Pollution; Apr2001, Vol. 127 Issue 1-4, p157-171, 15p |
| Abstrakt: |
Migration and chemical availability of 137Cs and 90Sr in the long-term was studied on a 36-yr-old deposition experiment on pasture consisting of a sandy soil and a clay soil, contaminated in 1961 with radionuclides in aqueous solution. Comparisons were made with a study of the same soils in 1967. Soil samples to 55 cm depth were analysed for 137Cs and 90Sr to establish the vertical distribution. Chemical availability was studied using sequential extractions with H2O, NH4Ac, NH2OH·HCl, H2O2 and HNO3. Both 137Cs and 90Sr were found at all depths in both soil types. Cs-137 was predominantly retained within the upper 10 cm (70%) in both soils. For 90Sr, the soils differed significantly, retention within the upper 10 cm was 27% in sandy soil and 47% in clay soil. Migration since 1967 was faster in the sandy soil for both nuclides. More than 95% of 137Cs was bound in the acid-digestible and residual fractions in both soils. The residual fraction was larger in clay soil. 90Sr was highly available in both soils. No residual fraction was found, and the easily exchangeable fraction was 63–75%. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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