小型河流库坝建设对河道重金属元素分布的影响

发布时间：2018-11-06 15:24

【摘要】：【目的】研究小型河流库坝建设对河道沉积特征及重金属元素分布特征的影响。【方法】以淮河4级支流索河三仙庙水库至丁店水库段为研究对象,依据水流方向及库坝位置将其分为上、中、下3段,分别采用单因素方差分析和冗余分析,对3段的表层沉积物及下表层沉积物粒度特征,以及As、Cr、Pb、Cd、Cu、Hg和Zn共7种重金属元素进行了分析和评价。【结果】表层和下表层沉积物各粒度组分和有机碳含量基本相同,但表层重金属含量略高,表明库坝建设后该区域沉积环境总体上较为稳定,而重金属污染有所加重;3段间的水文条件差异较大,上段常处于相对断流状态,沉积物中砂粒含量较多,中段水流较小,粉粒和黏粒等粒径较小的沉积物粒度组分含量较高,下段常年积水,但水位变化较大,沉积物特征与上段相似;重金属元素分布特征显示其在中段的含量均高于上段和下段;有机碳在中段的含量极显著高于其在上、下段的含量。【结论】总体上,库坝建设改变了河流的水文条件,影响沉积物特征,对重金属元素分布影响较大,使得中段重金属元素相对容易富集。
[Abstract]:[objective] to study the influence of small river reservoir dam construction on the sedimentary characteristics and the distribution of heavy metal elements in the channel. [methods] the section between Sanxianmiao Reservoir and Dingdian Reservoir, the fourth grade tributary of the Huaihe River, was taken as the object of study. According to the direction of flow and the location of reservoir dam, it is divided into upper, middle and lower sections. The grain size characteristics of surface sediment and lower surface sediment and As,Cr,Pb,Cd,Cu, are analyzed by single factor variance analysis and redundancy analysis, respectively. Seven kinds of heavy metals were analyzed and evaluated by Hg and Zn. [results] the grain size components and organic carbon contents of surface and lower surface sediments were basically the same, but the contents of heavy metals in surface layer were slightly higher. The results show that the sedimentary environment in this area is stable and heavy metal pollution is more serious after dam construction. The hydrological conditions of the three sections are quite different, the upper section is often in a relatively broken state, the sediment contains more sand particles, the flow in the middle section is smaller, the granularity components of the sediment with smaller particle size such as silt and clay are higher, and the lower section has accumulated water all the year round. However, the water level varies greatly, and the sediment characteristics are similar to those in the upper section. The distribution characteristics of heavy metal elements showed that the contents of heavy metals in the middle segment were higher than those in the upper and lower segments. The content of organic carbon in the middle section is significantly higher than that in the upper and lower segments. [conclusion] generally speaking, dam construction has changed the hydrological conditions of the river, affected the sediment characteristics, and greatly affected the distribution of heavy metal elements. The heavy metal elements are relatively easy to enrich in the middle section.
【作者单位】：南京大学生命科学学院;中国电建集团华东勘测设计研究院有限公司;山东建筑大学市政与环境工程学院;
【基金】：国家水体污染控制与治理科技重大专项项目(2012ZX07204004) 国家自然科学基金项目(41271197,51309242)
【分类号】：X52

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