红壤中稀土元素结合形态的研究及其意义

本文对五个不同母质来源的红壤剖面层中稀土元素的结合形态进行了研究，统计表明稀土元素的各种结合形态中以残渣态为主，其次为铁锰氧化物结合态，大部分稀土元素的可交换态、碳酸盐结合态、有机质结合态及酸溶态含量较为接近。各剖面层中稀土元素结合形态的变化大致可分为两类，一类以表层含量较高，如有机质结合态；另一类以深层含量较高，如可交换态、碳酸盐结合态、残渣态和酸溶态，而铁锰氧化物结合态变化较复杂，但主要集中在深层。不同母质对不同稀土元素的各种结合形态亦有一定的制约作用，表现为某些稀土元素的一些结合形态在一种或几种母质的红壤中占主导地位。本文还对稀土元素的各种结合形态与红壤的硅酸盐成分及其有机质含量、ｐＨ值间进行了相关分析，认识到结合形态与红壤本身成分间的密切关系。

Research on the Chemical Forms of REE in Red Soils.

This paper deals with chemical forms of REE in the profiles of Red soils which have different parent materials,statistic results showed that most REE existed as residual form,secondly as combined by Fe,Mn oxides.The different forms of REE changed with the depth of profiles,and the difference of parent materials influenced the forms of REE greatly.Results Based on correlation analyses among chemical forms and soil organic matter.pH value and chemical composition of red soils showed that there was closely relationship between chemical forms of REE and red soils itself.The form of REE in red soils can make a great influence on environmental pollution of REE,the result showed that red soils could give out much more REE in acid condition so as to accumulate to pollute environment.