Soil-Soil Solution Distribution Coefficients for Se, Sr, Sn, Sb, And Cs in Japanese Agricultural Soils

摘要

In this study, soil-soil solution distribution coefficients (K_(d~s)) for five radionuclides (Se-75, Sr-85, Sn-113, Sb-124, and Cs-137) were determined by batch sorption tests in 142 Japanese agricultural soil samples (63 paddy soil and 79 upland soil samples). The results showed that Se- and Sb-K_d data did not have a normal or a log-normal distribution, but Sr-, Sn-, and Cs-K_d data did have a log-normal distribution. Further, Se-, Sr-, and Cs-K_d values differed between paddy and upland soil samples in t-test (p < 0.05). Spearman's rank correlation test was carried out to investigate correlations between K_d values for each radionuclide and soil properties. The combination of the K_d value and the soil property having the highest correlation coefficient (R_s) for each radionuclide was as follows: Se-K_d - concentration of water soluble P (R_s = -0.51); Sr-K_d - concentration of water soluble Ca (R_s = -0.57); Sn-K_d -concentration of water soluble Sr (R_s = 0.57); and Sb-K_d - concentration of water soluble P (R_s = -0.67). Although there were no soil properties which had a good correlation with Cs-K_d values for all soil samples, the best correlated soil property with Cs-K_d values was concentration of water soluble ammonium ion (R_s = -0.48) for upland soil samples.