沅江下游入湖段河床沉积物重金属污染特征

发布时间：2018-12-08 15:50

【摘要】：对沅江入湖沉积物进行钻探取样,利用等离子质谱仪(ICP-MS)对沉积物重金属进行分析。结果表明:重金属Ba、Sc、V、Th、U、Cu、Co、Ni、Cr等在沉积物中含量变化相对稳定,分布相对均匀;而Mn、Zn、Pb、Mo、Cd、Tl、Bi等重金属的含量变化大,分布不均匀。重金属含量柱状剖面变化特征及富集系数(EF值)的计算结果显示:沉积物中Cd达显著富集,而Sc、V、Mn、Pb、Bi等为中等富集程度。沉积物中存在3个重金属富集层,即中下部Pb、Tl、Bi富集层;中上部Pb、Cr、Ni、Cu富集层;浅表部V、Cr、Mn、Ni、Cu、Zn、Pb、Cd、Tl、Bi等多种重金属富集层。地累积指数(Igeo)和综合富集指数(EI)评价结果显示:沅江入湖沉积物重金属污染程度自河床深部向浅部,污染程度趋于增强,污染元素组合趋于由Pb-Bi的单一元素组合向由V-Cr-Mn-Ni-Cu-ZnPb-Cd-Bi组成的复合元素组合变化。且自上游向下游,沉积物重金属污染程度趋于降低。这种重金属污染空间变化特征与区域人为活动有关,值得进一步研究。
[Abstract]:The sediment of Yuanjiang River was drilled and the heavy metals were analyzed by plasma mass spectrometer (ICP-MS). The results show that the content of heavy metal Ba,Sc,V,Th,U,Cu,Co,Ni,Cr in sediments is relatively stable and the distribution is relatively uniform. However, the content of heavy metals such as Mn,Zn,Pb,Mo,Cd,Tl,Bi changed greatly and distributed unevenly. The characteristics of heavy metal contents in columnar profile and the calculation of enrichment coefficient (EF) showed that Cd in sediments was significantly enriched, while Sc,V,Mn,Pb,Bi was moderately enriched. There are three heavy metal enrichment layers in the sediments, namely, the Pb,Tl,Bi enrichment layer in the middle and lower part, the Pb,Cr,Ni,Cu enrichment layer in the middle and upper part, and many other heavy metal enrichment layers in the shallow part, such as the Pb,Tl,Bi PbPbPbPbPbPbPbPbPbPbPbPbPbCU TlOBi in the shallow part. The evaluation results of (Igeo) and (EI) show that the heavy metal pollution degree of the sediment from Yuanjiang River into the lake increases from the deep to the shallow of the river bed, and the pollution degree tends to increase. The composition of contaminated elements tends to change from a single element combination of Pb-Bi to a composite element composed of V-Cr-Mn-Ni-Cu-ZnPb-Cd-Bi. From upstream to downstream, heavy metal pollution in sediments tends to decrease. The spatial variation of heavy metal pollution is related to the regional human activities, which is worthy of further study.
【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实验室;
【基金】：国家自然科学基金项目(41073095,41071216) 湖南省高校科技创新团队支持计划(2014)
【分类号】：X52

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