SORPTION OF CS-137 FROM UNDISTURBED FOREST SOIL IN A ZEOLITE TRAP

A method to study the time-integrated migration of radiocaesium (Cs-13 7) from undisturbed coniferous forest soil cores is presented, which i s based on a natural zeolite trap enclosed in a semi-permeable membran e that can be mounted into soil cores. Results show that higher zeolit e trapping of Cs-137 occurred in a forest soil with high soil-plant tr ansfer parameters, low pH and high organic contents. Part of the biolo gically bound Cs-137 that was associated within the soil microflora an d microfauna appears to increase the migration of Cs-137 after heating of the soil cores. Therefore, migration and mobility of Cs-137 in for est soil seems to depend to a major extent upon the soil's physical an d chemical parameters, particularly the activity concentration of Cs-1 37 in soil solution, soil pH, percentage of soil organic matter (OM%) and soil mineral type.