Analysis of soil aggregates contaminated by 137Cs via particle size classification and X-ray diffraction

We subjected 137Cs-contaminated soil to stirring and particle classification to reduce the contaminated soil volume. 137Cs activity as a function of particle diameter changed drastically as the weight ratio of soil/water varied; 85% of all 137Cs was adsorbed to particles of minimum diameter after stirring. Soil argillites (smectites, vermiculites, and illites) adsorbed 137Cs. We used X-ray diffraction (XRD) analysis to measure the soil contents; the 137Cs distribution as a function of soil particle diameter mirrored the smectite levels revealed by the XRD peak intensities. Thus, smectic was the main absorbent of 137Cs.