Migration of 137Cs adsorbed on fine soil particles through soil layer

The experiments on the migration of 137Cs adsorbed on fine soil particles in unsaturated sandy soil layers were carried out. The soil layer reduced the concentration of 137Cs in the effluent, but did not retard its migration. The concentration of 137Cs remained in the soil layer increased in proportion to the amount of 137Cs introduced. By the measurement of size distribution of fine soil particles, it was revealed that the concentration of 137Cs in the effluent decreased exponentially with the length of layer in the case of monodispersed fine soil particles. From these results, the first-order irreversible reaction formula was obtained in order to formulate the reaction of 137Cs adsorbed on fine soil particles with soil layer. A good agreement was obtained between the predicted result by polydispersed irreversible model and experimental one. (author)