湘江长潭株段河床沉积物重金属污染源的铅同位素地球化学示踪

发布时间：2018-08-30 12:58

【摘要】：本次工作利用等离子质谱仪(ICP-MS)对湘江长沙-湘潭-株洲河段河床沉积物重金属含量和铅同位素组成进行了系统的分析。结果表明,河床沉积物富集V、Cr、Mn、Co、Ni、Th、U、Cu、Pb、Zn等多种重金属,其中Cu、Zn、Pb等重金属于株洲段沉积物中达高度至极度富集。沉积物重金属的富集特征暗示沉积物存在较严重的重金属污染。沉积物铅同位素组成以相对富Th铅为特征,具明显的人为源和自然源铅,其~(206)Pb/~(207)Pb值在1.1723至1.1855之间,~(206)Pb/~(208)Pb值在0.4760至0.4786之间。其中自然源铅主要为花岗岩铅,而人为源铅则为铅锌矿矿石铅和燃煤铅构成,即沉积物铅同位素组成为花岗岩铅、铅锌矿矿石铅、燃煤铅组成的三元混合铅。铅同位素比例估算显示,长沙、湘潭段沉积物铅锌矿矿石源铅比例平均依次为23%、32%,燃煤源铅比例平均依次为47%、23%,自然源铅比例平均依次为30%、45%;株洲段沉积物的自然源铅比例较低,平均为17%,而矿石铅和燃煤铅的比例较高,平均依次为34%和49%。V、Mn、Co、Cu、Zn、U等其他重金属与Pb一样,长沙、湘潭段沉积物人为源比例小于67%,株洲段沉积物人为源比例达70%。因此,湘江长潭株段河床沉积物重金属污染问题值得引起高度重视。
[Abstract]:The heavy metal content and lead isotopic composition of sediment in Changsha Xiangtan Zhuzhou reach of Xiangjiang River were systematically analyzed by plasma mass spectrometer (ICP-MS). The results show that the sediment of river bed is rich in many kinds of heavy metals, such as V _ (Cr) Cr _ (mn) Co ~ (2 +) Ni ~ (+) ~ (1) ~ (1) (Cu,Zn,Pb) and so on. Among them, the heavy metals such as Cu,Zn,Pb are highly enriched in the sediments of Zhuzhou section. The enrichment characteristics of heavy metals in sediments suggest that there are serious heavy metal pollution in sediments. The lead isotopic composition of sediments is characterized by relatively rich Th lead, with obvious anthropogenic and natural lead, with ~ (206) Pb/~ (207) Pb values ranging from 1.1723 to 1.1855 Pb/~ (208) Pb values ranging from 0.4760 to 0.4786. The natural lead is granite lead, while the artificial lead is lead-zinc ore lead and coal-fired lead. The lead isotopic composition of sediments is granite lead, lead-zinc ore lead, coal-fired lead, ternary mixed lead. The estimation of lead isotopic ratio shows that the average lead ratio of lead ore source in Changsha and Xiangtan sections is 23%, that of coal source is 470.23%, that of natural source lead is 30 ~ 4545%, that of Zhuzhou section is low, and that of natural source lead ratio of Zhuzhou section is lower. The average ratio of lead in ore and lead in coal combustion is 34% and 49% respectively, which is the same as Pb. The ratio of anthropogenic source of sediment in Changsha and Xiangtan is less than 67 and 70 in Zhuzhou. Therefore, heavy metal pollution in the sediment of Xiangjiang Changtan reach deserves high attention.
【作者单位】：湖南师范大学资源与环境科学学院;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;中国科学院广州地球化学研究所;
【基金】：湖南省高校科技创新团队支持计划项目(2104) 国家自然科学基金(41073095) 湖南省高校创新实验平台项目(12K034)
【分类号】：P597;X142

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