La3+、Yb3+在土壤和矿物中的吸附特征及其环境意义

实验研究了轻稀土镧离子Ｌａ~３＋和重稀土镱离子Ｙｂ~３＋在赣南稀上矿区的土壤及风化次生矿物中的吸附特性，结果表明，土壤和矿物对稀土元素的吸附过程符合Ｌａｎｇｍｕｉｒ和Ｆｒｅｎｄｌｉｃｈ等温吸附方程，ｐＨ值是影响吸附作用的主要因素。随着ｐＨ值的变化，Ｌａ~３＋和Ｙｂ~３＋在土壤和次生矿物上的吸附能力也发生变化。Ｌａ~３＋与Ｙｂ~３＋在土壤和次生矿物中的吸附等势点ｐＨ值分别为６．２６和５．２８．在等势点ｐＨ值以下，Ｌａ~３＋的吸附势大于Ｙｂ~３＋；在等势点ｐＨ值以上，Ｙｂ~３＋的吸附势相对较高。土壤和次生矿物对轻、重稀土元素的吸附特征以及对稀士元素的分布、分异、成矿和生态效应具有重要意义。

The adsorption of La3+ and Yb3+ on soil and mineral and its environmental significance

The adsorption of light rare earth elements(LREE)La3 and heavy rare earth elements (HREE)Yb3 on soil andweathering mineral(<63 m) of REE mine area in southem Jiangxi province was studied by experimental approach.Results showed that langmuir and Frendlich equations were fitable to the adsorption procedure and that PH value is theimportant factor to effect adsorption. With the PH value changed, the adsorption capacity of La3 and Yb3 also changes.The adsorption epuipotential points of La3 and Yb3 on soil and mineral are PH 6.26 and PH5.28, respectively. Under thePH value of equiqutential point the adsorption capacity of La3 is higher than Yb3 ;on the contrast, it is converse.