安徽长江主要支流悬浮物重金属元素分布特征及其指示意义

Distribution characteristics of heavy metals in suspended sediments of major Yangtze River tributaries in Anhui Province and its implications

文章在安徽省境内的长江主要支流采集了枯水期和丰水期的悬浮物样品,测定其中重金属质量比。结果表明,这些河流的悬浮物中重金属元素富集现象明显,相对于流域土壤平均含量,悬浮物中重金属元素的富集系数为Cd>Cu>Zn>Hg>Pb>Ni,其中Cd的富集系数超过30倍。这些悬浮颗粒在下游冲积平原成为成土母质的重要成分,使之具有较高的重金属背景含量。沿江地区土壤Cd的富集较其他元素更为显著,与Cd在悬浮物中的富集系数大于其他元素有关。

Samples of suspended sediments were collected from major Yangtze River tributaries in Anhui Province both in high water level and low level periods, and the mass ratio of heavy metals in the samples was measured. The results show that these sediments are highly enriched with heavy metals. Compared with the average concentrations of these metals in surface soils of the catchment, the enrichment coefficient of the suspended sediments follows the order. Cd; Cu; Zn; Hg; Pb; Ni, in which the enrichment coefficient of Cd is over 30 times. These suspended particles have become the important component of soil parent materials in the alluvial plain at the lower reaches of the rivers and the alluvial sediments there normally have higher contents of heavy metals than other soil parent materials. The enrichment coefficient of Cd in the suspended sediments is larger than those of other elements, resulting in the natural enrichment of Cd in the soils along the Yangtze River.