长江武汉江段水体中稀土元素的含量和形态

本文采用中子活化分析技术同步研究了稀土元素在长江武汉江段水－悬浮物－沉积物中的地理含量分布及其赋存形态。结果表明，稀土元素在河水中溶解态含量极微，而悬浮态含量较高变幅较大。沉积物与悬浮物中稀土元素含量相近，其含量高低与粒级大小呈负相关，与矿物组成密切相关；稀土元素分布模式均为轻稀土富集、Ｅｕ亏损型。各元素赋存形态均以结晶态为主，各形态所占比例的排序为结晶态≥有机硫化物态＞铁锰氧化物态＞碳酸盐态≥可交换态。各稀土元素相对比较，５种形态的分配比例有一定差异，中稀土Ｅｕ、Ｓｍ、Ｔｂ较轻，重稀土的结晶态所占比例低，而其它形态则相反。

A STUDY ON THE CONTENTS AND SPECIES OF RARE EARTH ELEMENTS IN THE WATER BODY IN THE WUHAN SECTION OF THE CHANGJIANG RIVER

The contents and partitioning characteristics of rare earth elements (REE) in Wuhan section of the Changjiang River were analysed by neutron activiation analysis (NAA). The contents of solvable fraction of REE in the river was very limited,with the same results as other rivers. On the other hand.the contents of suspended fraction of REE in the river varied in a wide range. It varied with the variation of contents of suspended matter in the water.Contents of REE in the sediments were almost the same with those in the suspended matter. REE were accumulated in fine grained particles,and this showed strong relationship with minerals.The distribution modes showed strong accumulation in the light REE and relatively deficit in Eu. The partitioning charateristics of REE in the sediments and suspended matter were quite similar,With the main amount in residual forms. The amount of five forms obeyed the following order:residual> > bound to organic matter>bound to FeMn oxides> boune to carbonates> > exchangeable. Compared with light and heavy REE, the medium REE(Eu, Sm, Tb) had relatively low percentages in the residual form and high in the forms which are bound to organic matter and Fe-Me oxides. The water bodies of the Wuhan section of the Changjiand River had not been polluted by REE.