包头市四道沙河流域污灌区稀土元素的分布特征

【目的】研究包头四道沙河流域污灌区水系沉积物、表层土壤中的稀土元素分布特征，旨在为污灌区的土壤环境质量评价及土壤重金属污染修复提供依据。【方法】采集包头市南郊四道沙河流域污灌区的水系沉积物、农田土壤样品，测定样品中不同稀土元素含量，系统分析污灌区水系沉积物、农田土壤中的稀土元素分布特征和分馏特征。【结果】污灌区的轻稀土元素总量是重稀土元素的42.43倍，轻稀土元素与重稀土元素总量的比值为12.36～128.72。研究区轻、重稀土元素分馏非常明显，且以轻稀土元素的富集度较高，Eu元素有相对微弱亏损，Ce元素在局部地区分布明显异常。【结论】研究区轻稀土元素高度富集，人类活动导致外源轻稀土在污灌区环境中超量积累，外源轻稀土元素对包头市污灌区的农田土壤生态环境具有重大影响。

REE distribution characteristics of sewage irrigation in Sidaoshahe basin of Baotou City

【Objective】 The research was to study characteristics of rare earth elements(REE) distribution in stream sediment and farmland surface soil of sewage irrigation in Sidaoshahe basin of Baotou,providing a scientific basis to evaluate the soil environmental quality of sewage irrigation area and repair of heavy metal pollution in soil.【Method】 Stream sediments and farmland soils samples were collected in Sidaoshahe basin in the southern suburbs of Baotou to determine the content of REE.Distribution characteristics and fractionation characteristics were analyzed systematically in stream sediments and farmland soils.【Result】 The results indicated that the average total content of light rare earth elements(LRE) was 42.43 times of heavy rare earth elements(HRE).The value of ∑LRE/∑HRE was 12.36-128.72,LRE and HRE separated obviously,showing LRE relatively rich.Eu was relatively slightly lost and Ce showed significantly abnormal in some places.【Conclusion】 Full enrichment LRE was found in the study area because human activities lead to excess accumulation of exogenous LRE in the environment of sewage irrigation,external LRE to soil ecological environment in sewage irrigation in the southern suburbs of Baotou City has a significant impact.