Sorption of manganese,cobalt, zinc,strontium, and cesium onto agricultural soils: Statistical analysis on effects of soil properties

In this study, distribution coefficients (K _d s) of five radionuclides (⁵⁴Mn, ⁶⁰Co, ⁶⁵Zn, ⁸⁵Sr, ¹³⁷Cs) were measured by a batch technique for 36 agricultural soils (paddy and upland soils) collected in Japan. Twelve properties of the soils and measured K _d ss were examined for their probability distributions. Soil properties showed log-normal type distributions, except pH(H₂O), and total calcium and potassium contents for which distributions were normal. The K _d s distributions were also lognormal types except for ⁵⁴Mn-K _d s? No significant difference in soil K _d s was found between upland and paddy soils. The K _d s were analyzed for correlations with each soil property. The combinations showing the highest correlation were: the exchangeable calcium for ⁵⁴Mn and ⁶⁰Co; the water content for ⁶⁵Zn; the cation exchange capacity for ⁸⁵Sr; and the exchangeable potassium for ¹³⁷Cs, For ⁵⁴Mn and ⁶⁰Co, their K _d s also correlated with supernatant pH. Only ⁸⁵Sr-K _d s showed an adequate correlation with the value if the CEC divided by the supernatant EC. For the other four nuclides, some other mechanisms besides ion exchange seemed to be working.