【作者】 王霞；

【导师】 任珺；

【作者基本信息】 兰州交通大学 ， 水土保持与荒漠化防治， 2014， 硕士

【摘要】 近年来，随着黄河流域经济和社会的高速发展，城市人口的膨胀，流域内不断排入了大量的污染物，黄河流域干支流的污染情况也日趋严重，因此，研究水质及底泥的污染状况对生态环境保护具有重要的现实意义。本文采用野外采样与室内分析方法，以黄河上游四个省份（青海省、甘肃省、宁夏回族自治区、内蒙古自治区）典型地区共122个采样断面的底泥沉积物为研究对象，采集和分析0~5cm表层底泥及岸边的对照样品，系统调查和研究了底泥中8种重金属（Cu、Fe、Mn、Ni、Zn、Cr、Pb与Cd）的含量特征及空间分布规律，通过相关性研究和主成分分析来了解各个重金属元素的来源情况，并采用地质累积指数法、沉积物富集系数法、污染负荷指数法综合评价了黄河上游四个省份典型地区底泥重金属的污染程度。得出以下结论：（1）黄河上游四个省份典型地区底泥重金属的含量从大到小均为Fe＞Mn＞Cr＞Zn＞Ni＞Cu＞Pb＞Cd。根据底泥中各个重金属的平均含量与背景值的倍数来看，重金属Cr的污染程度较严重，Zn的污染程度最弱。各重金属元素间的标准差和变异系数均相差较大，反映了各个采样点的污染程度不尽相同，这可能与重金属的来源情况、人类活动影响的大小及方式等因素有关。（2）黄河上游四个省份典型地区底泥重金属Cu、Fe、Mn、Zn四者之间均呈显著的相关关系，受控于第一因子，它们在沉积物中分布比较均匀，以自然沉积为主，较少受到人为干扰，属于“自然源元素”，这些元素的来源、运输、富集影响因素等方面有相似的地球化学行为；Cd与Cr呈显著的相关关系，受控于第二因子，它们的来源和分布具有相似性，属于“人为源元素”，主要为机械制造、金属矿山冶炼、电力、化学原料、化石燃料燃烧、塑料、半导体、超导等。Ni与Pb可能受到自然地质背景与人类活动的双重影响。（3）重金属元素Fe、Mn与Zn为无污染到弱污染程度，可能来自于自然沉积、地壳运动等自然来源。重金属Cu、Ni、Pb与Cd为弱污染程度，来自于结石碎片等因素。重金属Cr属于中等污染程度，可能由人为活动引起，比如工业废水、车辆尾气排放、化学品制造、煤矿矸石中的Cr元素流失较严重并通过地表水流入河流等。总体而言，黄河上游四个省份整条流域为无污染到中等污染程度。更多还原

【Abstract】 With the rapid development of the economy and society, the expansion of the urbanpopulation, and more and more pollutants are discharged into the yellow river, the problem ofthe water pollution in yellow river is more serious in recent years. Therefore, the study ofpollution condition of water quality and sediment has an important practical significance forthe ecological environment protection.Taking the method of field sampling and laboratory analysis. This thesis took the surfacesediments of122sample points of typical regions in four provinces (including Qinghai,Gansu, Ningxia and Inner Mongolia) in upstream of Yellow Rivers the research object,collected and analysed the surface sediments and control samples in0~5cm, investigated andresearched systematically the characteristic of content and spatial distribution pattern of eightheavy metals (Cu, Fe, Mn, Ni, Zn, Cr, Pb and Cd) in surface sediments. We can understandthe sources of each heavy metal element through the relevant research and principalcomponent analysis, and the evaluating pollution level in surface sediments from typicalregions in four provinces in upstream of Yellow river by the method of Geo-accumulationIndex, Sediment Enrichment Factors and Pollution Load Index. The following conclusionsare:(1) The mean values of the heavy metal contents of the surface sediments from the fourtypical provinces in upstream of Yellow River are arranged in the decreasing order: Fe>Mn>Cr>Zn>Ni>Cu>Pb>Cd. According to the multiples between the average value and thebackground value of the heavy meatals, the pollution of Cr is the most serious, and Zn is thelightest. Standard deviation and variation coefficient between the heavy metal elements havelarge difference. The result indicates that pollution levels between each sample point have bigdifference, it may be related to some factors, such as heavy metal sources，the influence andmanners of human activities.(2)There is a significantly positive correlation relationship between Cu, Fe, Mn and Znin surface sediments from the four typical provinces in upstream of Yellow river. These heavymetals which are controlled by the first factor, well-distributed in sediments, mainly in naturalsedimentation, and less affected by human disturbance are belong to the “natural sourceelements”. So they have similar geochemical behavior in sources, transportation andenrichment factors. The correlation between Cd and Cr is significantly positive, they belongto the “artificial source element” with the control of the second factor, and the source anddistribution of them are similar. The main sources are from several kinds of industrialprocesses such as machinery manufacturing, smelting metal mines, electric power, chemical raw materials and the burning of fossil fuels, plastics, semiconductor, and superconducting etc.The source and distribution of Ni and Pb may be affected by natural geological backgroundand human activity.(3)The pollution of the Fe, Mn and Zn is from no pollution to weak pollution, theseelements may come from natural sources such as natural sedimentation and crustal movement.The pollution of Cu, Ni, Pb and Cd is weak, these elements come from stone fragments andother factors. Heavy metal Cr which belong to moderate pollution may be caused by humanactivities, such as industrial wastewater, vehicle emissions, chemical manufacturing, and thesevere loss of element Cr from coal mine going into rivers through surface water and so on.Generally speaking, the pollution level of four provinces in upstream of Yellow River is fromunpolluted to moderately polluted degree.更多还原