Accumulation of 137Cs in soils on different bedrock geology and textures

• DOI: 10.1007/s10967-006-0054-4
• Publication Date: 2006-01-13T08:28:41Z
• Authors: Hyun-Ju Cha; Mun-Ja Kang; Geun Ho Chung; Geun Sik Choi
• Keywords: Bedrock

Vertical distributions of 137 Cs activilies were studied for the soils of six areas, Korea, in different texture and mineral composition. The 137 Cs activities in soil vary greatly with depth and by sites. The 137 Cs concentrations are the highest at the topsoil and decrease exponentially with depth at all sites. The 137 Cs at the top 5 cm soil account for most 137 Cs inventory in each site and is positively correlated with annual precipitation, organic carbon and clay fraction of each soil. High 137 Cs activities are found at two sites, Jeju and Goseong in much different textural properties. The Jeju soil consists of organic-rich fine-grained clays and the Goseong soil consists of organic-poor gravelly sands with little clay. The high 137 Cs activity in the Jeju soil is attributed to clays and organic matter that provides large sorption sites for Cs. Sorption of Cs + was investigated for coarse-grained soils in order to know the mineralogical effects to the accumulation of 137 Cs in the Goseong soil consisting of gravelly sands. Soil particles were separated by size, contacted with CsNO 3 solution and analyzed by electron microprobe. The results of the electron microprobe showed that weathered biotite is the main contributor of Cs sorption in the Goseong soil.