^(95)Zr在鱼-海水-底泥模拟生态系统中的迁移与分布  

Migration and distribution of ^(95)Zr in a simulated marine fishes-seawater-sediment ecosystem

作　　者：史建君[1] 李明云[2] 

机构地区：[1]浙江大学原子核农业科学研究所,杭州310029 [2]宁波大学海洋与水产系,宁波315211

出　　处：《生态学报》2003年第2期330-335,共6页Acta Ecologica Sinica

基　　金：国家自然科学基金资助项目 ( 39970 1 4 7);浙江省核农学重点实验室人才基金资助项目~~

摘　　要：采用同位素示踪技术研究了 95Zr在鱼 -海水 -底泥模拟系统中的迁移与分布。旨在探明海洋鱼类对 95Zr的吸收以及95Zr在海水生态系统中的行为特性。结果显示 :( 1 )海水中的 95Zr比活度随时间呈快速下降 ,降至一半所需的时间仅为 0 .2 d;底泥吸附的95Zr主要集中在表层 ( 0～ 2 .5 cm) ,至试验后期 ( 1 3～ 2 0 d)其量占总量的 99.5 %以上 ,表明来自于海水中的95Zr被表层底泥吸附 ,不易随渗流水向下迁移 ,海泥对95Zr有强烈的吸附作用。 ( 2 )中华乌塘鳢从水体中摄入和吸收95Zr的主要器官是肠胃道 (内脏 ) ,与水体直接接触而吸附、吸收的95Zr主要集中在鱼鳃和鱼鳍中。肉、骨、肝脏和鱼卵中的比活度均比较低 (略高于本底水平 ) ,表明通过肠胃道吸收和鳃、鳍等组织吸附、吸收的95Zr不易向肉、骨、肝脏和鱼卵等内部组织输运。 ( 3)运用封闭 3分室模型原理对实验数据进行拟合得 :鱼体中的比活度 Cf=0 .0 5 - 6.36e- 3.4 2 74 t+ 6.61 e- 0 .2 682 t,海水中的比活度 Cw =2 1 5 .42 e- 3.4 2 74 t+ 2 .0 0 e- 0 .2 682 t,底泥中的比活度 Cs=1 43.86+ 1 4.83e- 3.4 2 74 t-1 5 8.69e- 0 .2 682 t;方差分析结果表明各回归方程较好地反应了 95Zr在鱼 -海水 -底泥生态系统中的消长动态。The isotope tracer technique is used to study the dynamics of migration and distribution of 95Zr in a simulated marine fishes-seawater-sediment system, and its dynamics is described mathematically using a compartment model with a non-linear fitting method. The objectives of this study are (i) to clarify the behavior trait of 95Zr in marine ecosystem; (ii) to evaluate accumulation and distribution of 95Zr in marine fishes; and (iii) to simulate the dynamics of 95Zr in the marine fishes-seawater-sediment system based on a closed three compartments system model. Three glass pools with dimensions of 40cm×50cm×40cm were constructed. 12.5 kg of sea sediment was filled into each pool. And sediment depth was about 5 cm. The pools were flooded with 42l seawater. Eleven mL of 95ZrF 4 with a specific activity of 9.02×105Bq/ml was introduced into the seawater after one week. The seawater was stirred gently to get a homogeneous distribution of radionuclide. The radionuclide specific activity in seawater was 216.9Bq/ml. Seven marine fishes(Bostrichthys sinensis) were put into each pool. Seawater was added with intervals of 3 days in order to maintain a constant height of seawater. The samples were collected at the elapsed time of 0.25, 1, 2, 4, 8, 13 and 20 days. Four 5 ml aliquotes of seawater were randomly collected from each pool, and disposable plastic cups were filled with them (20 ml ) for activity measurements. A marine fishes was taken from each pool. The fish was divided into fin, viscera, liver, gill, skin, meat, bone, head and roe, and each part was weighed. They were afterwards cut into smaller pieces. Twenty grams samples from each part were put into the disposable plastic cups for measurements. In the meantime, two sediment columns were collected from each pool using a sediment sampler. Each sediment column was sectioned into two equal parts, and each part was smashed and mixed thoroughly. Afterwards 20 g of sediment samples were put into plastic cups for measurements. Eve

关 键 词：^95ZR 鱼-海水-底泥模拟生态系统 迁移 分布 海水生态系统 放射生态学核电站 

分 类 号：X591[环境科学与工程—环境工程]