【作者】 董运武；

【导师】 马建华；

【作者基本信息】 河南大学 ， 环境地理学， 2012， 硕士

【摘要】 目前，对土壤和水环境等重金属背景值的研究已经很多，但是对地表灰尘重金属背景值的研究鲜见报道。开封市位于黄淮海大平原的核心位置，是河南省重要化工产业区，其城市周边地区是河南省重要粮食主产区。本文在野外调查采样、室内化验分析的基础上，开展了地表灰尘重金属背景值的研究。地表灰尘和土壤样点布设遵循少受人为干扰、均匀性和随机性原则。样点距离开封市区10km以上，距县城或乡镇5km以上，距农村居民点0.5km以上，距主要公路1km以上。样品采集地点选择古老坟茔地、规模成片林地、田间小路、规模较大的永久性田埂和沟渠堤岸、长期荒芜的地面等。本研究采集了开封附近地区地表灰尘样品96个，表层土壤样品49个。用ICP-MS检测了各样品Cu、Zn、Ni、Pb、Cr、Cd、V、Co、Ga、Sr和Sb等11种重金属含量。检测过程中运用加标回收试验和均数控制图进行质量控制，加标回收率在95%～105%之间，控制样品值均在上、下控制限之间，数据均符合质量要求。按《GB/T4883-2008》要求采用Grubbs检验法和偏度-峰度方法两分别对灰尘和土壤重金属检测数据进行检验，共剔除15个灰尘离群数据和2个土壤离群数据，获得到有效数据共1578个。按照土壤元素背景值研究方法，分别开展开封附近地区地表灰尘和土壤表层重金属背景值研究，并与我国不同区域的表层土壤背景值开展对比分析，最后基于灰尘背景值对开封市幼儿园地表灰尘重金属污染状况进行了评价。其主要结论如下：（1）采用W检验法、置信带法和偏度峰度法对灰尘样品和土壤样品数据进行分布状态的检验表明，V、Co、Ni和Sr呈正态分布；Cr、Cu、Zn、Cd和Pb呈对数正态分布；Ga和Sb呈偏态分布。。（2）对于呈正态分布的重金属，以算数平均值和标准差的计算表征其背景值及其范围；对于呈对数正态分布的重金属，以几何平均值和几何标准差的计算来表示其背景值及其范围；对于呈偏态分布的重金属，以中位数表示其背景值，以5-95%所对应的数据区间表示背景值范围。结果表明，研究区地表灰尘V、Cr、Co、Ni、Cu、Zn、Ga、Sr、Cd、Sb和Pb的背景值分别为85.12、46.51、9.72、26.43、20.54、77.21、36.30、24.99、0.304、1.20和24.58mg/kg，背景值范围分别为41.08～129.16、1.64～68.37、5.32～14.12、12.55～40.32、11.38～37.08、47.80～124.71、32.59～42.19、177.82～272.15、0.152～0.610、0.88～1.76和14.73～41.02mg/kg。（3）研究区地表灰尘Cu、Zn、Pb、Cd、Cr和Sb等重金属的背景值高于本区土壤背景值，分别是表土背景值的1.02、1.06、1.07、1.01、1.26、1.35倍。经差别显著性检验发现，灰尘和表土Sb和Cr的背景值差别显著（P＜0.05），而其他重金属并无显著差别。地表灰尘Co、Sr、Ni和Ga等重金属的背景值低于表土背景值，分别是表土背景值的0.85、0.95、0.87、0.92倍，经差别性显著检验，均不存在显著性差别。与黄河下游潮土区和河南省表土重金属背景值相比，也得到了相似的结论。这可能是灰尘Cu、Zn、Pb、Cd、Cr和Sb等重金属主要赋存在较小的土壤颗粒物上，易发生空气迁移；而Co、Sr、Ni和Ga等重金属主要赋存在较大的土壤颗粒物上，不易发生空气迁移所致。另外也可能是由于第一类重金属受人类活动影响较显著，在土壤表面富累较多，经空气迁移和沉降后导致灰尘中的含量偏高，而表土背景值是0～20cm范围的均值造成的。（4）分别基于地表灰尘和黄河下游潮土背景值，利用地积累指数法（Igeo）和潜在生态风险系数法（RI）对开封市幼儿园地表灰尘重金属污染的评价结果显示，利用Igeo评价时，虽然基于两种标准的Cu和Pb污染等级没有变化，但基于灰尘背景值的Igeo均小一些；而基于灰尘背景值的Cr和Zn污染程度比基于土壤背景值低。利用RI评价时，所有重金属基于两种标准的评价结果均在一个等级，但是各点基于灰尘背景值的RI值均比基于表土背景值的RI值低4.32%～7.34%。用土壤背景值作为基准来参与地表灰尘的污染评价，结果出现偏高的现象，即高估了地表灰尘的污染程度，利用灰尘背景值参与地表灰尘的污染评价更加符合客观实际。更多还原

【Abstract】 Researches on background values of heavy metal in soil and water are many at present, but study onbackground values of heavy metal in surface are less. Kaifeng is located in the North China Plain, and it isan important chemical industry area of Henan Province, the region surrounding the city is an importantmain grain producing area of Henan province. Based on field investigation and sampling and laboratoryanalysis, we carry out the study on background values of elements in surface dust.In accordance with the principle of less human disturbance, uniformity and randomness of sampledistribution,96dust samples and49soil samples in the region surrounding Kaifeng are collected. Thesampling points are selected from Ancient graves, large scale woodland, loaning, larger permanent fieldedges and canal banks and long-term desert ground, which are more than10kilometers away from KaifengCity and more than5kilometers from counties or towns,0.5kilometers from villages and1kilometer frommain road.11trace element contents of Cu, Zn, Ni, Pb, Cr, Cd are measured by ICP-MS. Recovery testand mean control chart are applicated in checking process for quality control, the recovery ratio is between95%and105%, the assurance sample values are all between upper and lower limit and meet the qualityrequirements. Referring to GB/T4883–2008, dust and soil heavy metal values are respectively checkedby Grubbs test and Deviation-kurtosis test,15discrete data of dust and2of soil are eliminated, and1578effective data are got.According to methods of the analysis of background values of elements in soils, we carry out thestudy on heavy metal background value in surface dust and soil in the region surrounding Kaifeng, and campare it with background value in surface soil of different regions in China, then assess the level ofheavy metal pollution in surface dust in kindergarten of Kaifeng, and the main conclusions are as follows：1. Data distribution test methods of W test, confidence band test and the Deviation-kurtosis test areused to check the distribution of11sets of data. The results show that V、Co、Ni and Sr show normaldistribution, Cr、Cu、Zn、Cd and Pb show log-normal distribution, and Ga and Sb skewed distribution.2. Arithmetic mean and standard deviation are used to describe the normally distributing elements’background value and their range, geometric mean and Geometric standard deviation are used to describethe log-normally distributing elements’ background value and their range, and median is used to describeskewed distributing elements’ background value and5-95%corresponding interval to describe their range.The results are as follows.The background value of V、Cr、Co、Ni、Cu、Zn、Ga、Sr、Cd、Sb and Pb respectively are85.12,46.51,9.72,26.43,20.54,77.21,36.30,24.99,0.304,1.20, and24.58，and the range41.08～129.16mg/kg,1.64～68.37,5.32～14.12,12.55～40.32,11.38～37.08,47.80～124.71,32.59～42.19,177.82～272.15,0.152～0.610,0.88～1.76and14.73～41.02mg/kg.3. The background values of Cu, Zn, Pb, Cd, Cr and Sb in surface dust are higher than the soilbackground value of the region, they are respectively1.02,1.06,1.07,101,1.26and1.35times of it.According to significance testing, the background value of Sb in surface dust and soil is significantlydifferent (p＜0.05) from Cr, and there is no significant difference among the others. The backgroundvalues of Co, Sr, Ni and Ga in surface dust are lower, but not significantly, to that in surface soil, which arerespectively0.85,0.95,0.87and0.92times of that in surface soil. And camparing with the backgroundvalue of in moisture soil in area of the lower reaches of the Yellow River and surface soil in Henanprovince, we get a similar conclusion. It is probably because of that the heavy metals of Cu, Zn, Pb, Cr and Sb in surface dust are mainly attach on relatively minor soil particles so they are easily to occuratmosphere transport, and Co, Sr and Ga on relatively large soil particles so hardly to occur atmospheretransport. It is also probably because of that the first ones is more significantly influenced by humanactivities so accumulate more on the surface of soil and higher in surface dust after atmosphere transportand sedimentation but the surface background value is the mean value from0to20cm in soil.4. Respectively based on background values in surface dust and moisture soil of the lower reaches ofthe Yellow River, the condition of heavy metal pollution in dust in kindergarten of Kaifeng is assessed byIgeoand RI. The results show that when it is assessed by Igeobased on the two standards, the class ofpollution of both Cu and Pb is though not changed, but it is smaller based on background value in surfacedust, and the pollution of Cr and Zn based on background value in dust is less than that based onbackground value in soil. When it is assessed by RI, the pollution of all the heavy metals is within the sameclass based on the two standards, but it is4.32-7.34%lower based on background value in dust thanbackground value in soil. So it will be on the high side when surface dust pollution is aassessed based onsoil background value, in other words, it will be overvalued. Then it is more accordant with reality toassess the pollution of surface dust based on background value in surface dust.更多还原