茶树-土壤生态系统中HTO的迁移与消长动态

采用模拟污染物的同位素示踪技术研究HTO（氚水）在茶树-土壤模拟生态系统中的迁移规律。测定了植物和土壤样品中两种形态氚（自由水氚和结合态氚）的比活度，并应用具有相互交换的双库室开系统模型确定了茶和土壤分室的拟合方程。结果表明：引入土壤中的HTO，不仅在系统积分室间转移和分配，而且迅速向系统外扩散；HTO中的氚以自由水氚和结合态氚形式存在于茶树中，以吸湿性水氚和结晶水氚存在于土壤，其中自由水氚（或吸湿性不氚）远大于结合态氚（或结晶水氚）；对实验数据进行回归分析得；茶树植株中的总氚比活度Ct(t)=314.09(e^-0.0569t-e^-0.3777t)，土壤中的总氚比活度Cs(t)=136.73e^-0.3777t 112.22e^-0.0569t。

The transportation and accumulation-disappearance of HTO in the tea-soil ecosystem

The dynamics of transportation of HTO (tritium water) in a simulated tea soil ecosystem were studied on simulated pollutants using isotope tracer technique. The specific activities of two forms of tritium (free water tritium and bound tritium) in plant and soil sample were measured, and the fitting equation was confirmed by the open tow\|compartment system model with interchange. The results showed that HTO not only transferred to other compartments in the ecosystem, but also vaporized into atmosphere rapidly.Free water tritium and bound tritium were found in the tea, and hygroscopic and crystalline water tritium in the soil. The specific activity of free water tritium (or tritium of hygroscopic water) was higher than that of bound tritium(or crystalline water tritium ). The regression equation of transportation for the specific activity of total tritium in the tea and soil are C t( t )=314 09(e -0 0569 t -e -0 3777 t ) and C s( t )=136 73e -0 3777 t +112 22e -0 0569 t .