~(95)Zr在淡水生态系中的迁移动力学

采用模拟污染物的同位素示踪技术研究了95Zr在淡水生态系统中的迁移、消长和分配动态,并应用库室模型确定了各系统的拟合方程。结果表明:95Zr进入水体后发生沉淀,与其他离子进行络合,或为水生生物吸收、被吸附等形式在系统中迁移和转化,从而在各分室中分配和积累。在引入后的短时间内,池水中95Zr的比活度迅速降至一定值,而后缓慢下降;底泥通过离子交换或吸附富集了大量的95Zr;水葫芦也可在短期内吸附或吸收大量的95Zr;螺蛳和鲫鱼对95Zr的吸收能力较弱,螺蛳肉中95Zr的富集率大于在壳中的富集率,95Zr在鱼体内的分布主要集中在内脏中。95Zr在系统各分室的量随时间而变化。

TRANSFERENCE KINETICS OF RADIONUCLIDE NUCLIDE ~(95)Zr IN FRESH WATER ECOSYSTEM

The dynamics of transference,accumulation,disappearance and distribution of ~(95)Zr in a simulated aquatic ecosystem was studied by isotopetracer technique,and the fitting equation was established by application of the closed five-compartment model.The results showed that when ~(95)Zr was introduced into aquatic system,it was transported and transformed via depositing,complex with other ions,adsorption and absorption resulted in redistribution and accumulation in each compartment of the system.After applying,the specific activity of ~(95)Zr in water decreased rapidly to a certain value,and then decreased slowly.The sediment accumulated a large amount of ~(95)Zr by adsorption and ion exchange.The water calabash could also adsorb a large amount of ~(95)Zr in a short time.Snail and fish had a poor capability of adsorbing ~(95)Zr.The amount of ~(95)Zr in snail fresh was greater than that in the shell,and the distribution of ~(95)Zr in fish was mainly in the viscera.The amount of ~(95)Zr in each compartment was changed with time in the system.