中文摘要：

以黄河包头段为研究对象,探讨了该河段不同粒级沉积物中重金属的形态分布特征,并估算了各粒级沉积物对各形态重金属的贡献率。结果表明,铁锰氧化物结合态是黄河干流各粒级沉积物中Cu、Pb和Zn非稳定态的主导形态;总体上,黄河干支流沉积物中3种重金属各形态含量均随粒级增大而减小,表现明显的粒度效应;重金属形态分布的粒度效应是沉积物粒径大小与沉积物中有机质、碳酸盐、铁氧化物和锰氧化物等活性组分含量共同作用的结果,粒径是主控因素;Fe的含量是影响不同粒级黄河包头段沉积物中重金属的主导形态——铁锰氧化物结合态的主要因素;同一粒级沉积物中,不同重金属同一形态的含量总体有Zn〉Pb〉Cu的规律,与黄河中游沉积物重金属背景值Zn〉Cu〉Pb的研究结果不尽一致,揭示来自包头市工业废水的外源重金属对黄河水体沉积物的叠加影响。有机质结合态和铁锰氧化物结合态分别为支流各粒级沉积物中Cu及Pb、Zn的主导形态。不同粒级沉积物质量分数的差异导致不同粒级沉积物对重金属形态分布的实际贡献率不同。总体上,D5和D3粒级对黄河包头段沉积物重金属的形态贡献率为大,其潜在生态风险不容忽视。

英文摘要：

The Yellow River contains large amounts of sands,resulting in a peculiar hydraulic condition which is characterized by a magnificent interface between the particulates and water.In addition,Baotou section of the Yellow River suffers from severe heavy metal pollution receiving the industrial discharges from the Baotou city.Therefore,this study was carried out on Baotou section of the Yellow River based on its representativeness on the mechanism of heavy metal adsorption on water-sediment interface,and on the heavy metal spatial distribution,mobilization,transformation,and accumulation effects in sediments.Because of their persistence in the environment,heavy metals often pose threats to aquatic lives and plants in the environment.Based on the theories and methods of environmental geochemistry,biogeochemistry,pollution ecology and modern sedimentology,the speciation distribution characters of heavy metals such as Cu,Pb,Zn in the different grain sizes sediments and the contribution of the different grain sizes sediments on the concentrations of different heavy metals speciation were discussed in this work.The results indicated that the bound to Fe-Mn oxide was the dominant form of non-steady-state of Cu,Pb,and Zn in different grain sizes sediments from the Yellow River,and there were the concentration order of the bound to Fe-Mn oxide the bound to carbonate the bound to organic matter for Cu and Pb,while the bound to Fe-Mn oxide the bound to organic matter the bound to carbonate for Zn.The grain-size effects of the different species for the selected heavy metals were observed in this work which was the results of particle size and active components such as organic matter,carbonate and Fe-Mn oxides in different grain sizes sediments from the studied section of the Yellow River.In all of the factors,the particle sizes played a key role in affecting the concentration of different species of the selected heavy metals.Based on the experiments,it was found that the bound to Fe-Mn oxides was the dominant form in different