Published online by Cambridge University Press: 21 March 2011
Distribution coefficients of 226Ra and 227Ac on soils and tuff have been obtained by a batch method. The distribution coefficients of Ra on loam, two kinds of sand and tuff were 28m3/kg, 0.45m3/kg, 0.19m3/kg and 1.9m3/kg, respectively. A linear relationship between the distribution coefficients of Ra on each soil and Cation Exchange Capacity(CEC) of each soil was obtained to suggest cation exchange sorption reaction of Ra2+ on soil surface. Sorption-migration behavior of Ra in sand column has been studied. Most of Ra remained in the column after passing of 5,000 pore volume of the column, showing several times the distribution coefficients of Ra than that by the batch method. The distribution coefficients of 227Ac on the soil samples were in the range from 1m3/kg to 10m3/kg.