湘江下游河床沉积物稀土元素分布与污染特征  

Distribution and pollution characteristics of rare earth elements in riverbed sediments of lower reaches of Xiangjiang River,China

作　　者：郭馨彤 彭渤[1,2] 吴晶 邬思成 吴能球 董英帅 GUO Xin-tong;PENG Bo;WU Jing;WU Si-cheng;WU Neng-qiu;DONG Ying-shuai(College of Geographical Sciences,Hunan Normal University,Changsha 410081,China;Key Laboratory of Environmental Heavy-Metal Contamination and Ecological Remediation,Hunan Normal University,Changsha 410081,China)

机构地区：[1]湖南师范大学地理科学学院,长沙410081 [2]湖南师范大学环境重金属污染机理与生态修复重点实验室,长沙410081

出　　处：《矿物岩石地球化学通报》2023年第2期312-324,共13页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家自然科学基金资助项目(41073095);湖南省国内一流培育学科地理学建设项目(地理学-5010002);湖南省高校科技创新团队支持计划项目(12K034)。

摘　　要：稀土元素是一种新型环境污染物,其环境危害近年来备受关注。本研究利用电感耦合等离子质谱仪(ICP-MS)测定了湘江下游河床沉积物稀土元素含量,分析沉积物稀土分布特征,评价沉积物稀土污染程度,并对沉积物稀土污染进行生态危害预测分析。结果表明,湘江下游河床沉积物的稀土元素含量较高,其总稀土(ΣREE)含量为106~775 mg/kg(均值为319 mg/kg)。但自株洲河段向下游湘阴段,稀土元素含量明显降低。株洲等各河段沉积物的稀土配分模式都为轻稀土富集的上地壳稀土配分模式。根据沉积物的Eu/Eu*值,将湘江下游河床沉积物分为页岩型(S-型)和花岗岩型(V-型)两类稀土配分模式。其中V-型稀土模式沉积物的ΣREE为118~775 mg/kg,(均值为370 mg/kg),明显高于S-型稀土模式沉积物的ΣREE(106~396 mg/kg,均值为292 mg/kg),显示V-型的人为源带入特征。地累积指数评价显示,湘江下游河床沉积物的稀土元素污染达轻度到中度污染水平,主要发生在株洲、湘潭河段的沉积物中。潜在生态风险指数评价显示沉积物稀土污染达中度生态风险危害水平,应高度注意。Rare earth elements(REEs)are a new type of environmental contaminants,and their environmental hazards have received much attention in recent years.This present study investigated the distribution and contamination of REEs in in the lower riverbed of Xiangjiang River based on the ICP-MS analyses of the REEs contents in sediment cores collected from Zhuzhou,Xiangtan,Changsha and Xiangyin sections of the river.The results showed that the riverbed sediments had a high content of REEs,the total REE content ranged from 106 mg/kg to 775 with an average of 319 mg/kg(n=347).However,the content of REEs decreased significantly from the Zhuzhou section to the downstream Xiangyin section.The REEs partitioning patterns of sediments in all river sections,including Zhuzhou,were all upper crustal REES partitioning patterns rich in light REEs.According to the Eu/Eu∗value of sediments,the riverbed sediments in the lower Xiangjiang River could be divided into two types,the shale-type(S-type)and the granite-type(V-type)sediments.Among them,the total REE content in the V-type sediments ranged from 118 to 775 mg/kg with an average of 370 mg/kg,which was significantly higher than that of the S-type sediments,where total REE content ranged from 106 to 396 mg/kg with an average of 292 mg/kg,showing the enrichment characteristics of anthropogenic originated REEs.The geoaccumulation index evaluation showed that the REEs pollution in the riverbed sediments of the lower Xiangjiang River reached mild to moderate pollution levels,which mainly occurred in sediments of Zhuzhou and Xiangtan River sections.The potential ecological risk index evaluation showed that the sediment REEs pollution reached a moderate ecological risk hazard level,which should be highly noted.

关 键 词：稀土元素分配模式 人为源稀土 稀土元素污染 稀土元素生态风险 湘江 

分 类 号：P595[天文地球—地球化学]