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.