The Transference and Distribution of Tritium Water in the Soybean-Soil System
氚水在大豆土壤系统中的迁移与分布

The isotope trace techniques of simulation contamination were applied to explore the rule of transference and distribution of tritium water in a simulated soybeam soil ecosystem.The activity ratio of two forms of tritium in plant and soil sample were measured by 50 days simulation experiment.The results showed that when tritium water was entered the soil,it not only was transferred to other compartments in the system,but also vaporized into atmosphere rapidly.Both free water tritium and bound tritium were found in the soybean and the soil.The activity ratio of free water tritium reduced after reaching the maximum (19.4Bq·g-1 in root,12.3Bq·q-1 in stem and leaf) at 6th hour in the soybean.The bound tritium increased slowly.The activity ratio of total tritium in soybean root was upper than those in stem and leaf in the earlier stage,they reach equipoise each other in the later stage.The activity ratio of two tritium in the surface soil reduced continuously.The compartment model of tracer kinetic was applied to imitate the experimental data.The activity ratio of soil Cs=88.37e-11.847t+7.38e-0.030t and the activity ratio of soybean Cb=10.30(e-0.030t-e-11.847t) were gained.