【作者】 耿柠波；

【导师】 张瑞芹；

【作者基本信息】 郑州大学 ， 环境科学， 2012， 硕士

【摘要】 郑州是一个发展中城市,有较高水平的大气颗粒物污染。由于颗粒物及其携带的重金属长期以来对人类健康和环境气候的严重威胁,对郑州市大气颗粒物尤其是细粒子进行研究具有及其重要的意义。本论文为研究郑州市高新区大气颗粒物PM2.5及其中金属元素的污染特征及来源,于2010年1月～2011年1月在郑州大学新校区用美国Tisch的TE-6070D大流量颗粒物采样仪进行PM2.5的样品采集,用美国Agilent7500cx电感耦合等离子质谱仪(ICP-MS)分析其中的19种元素,并对其污染特征、季节变化及污染源进行了研究,得到了一些有意义的研究成果：(1)PM2.5年均浓度为175.4μg/m3,远超过欧盟(EU)的年均浓度限值25gg/m3WHO的年均限值10μg/m3,美国的年均限值15μg/m3,PM2.5季节变化明显,春、夏、秋、冬四个季节的平均浓度分别为179.6,131.6,185.5和210.1μg/m3。(2)PM2.5中测定的19种元素总体平均浓度从高到低依次为：Fe> K> Ca> Al> Zn> Mg> Pb> Mn> Na> Ba> Cu> As> Cr> Sr> Se> Cd> V> Ni> Co,与国内各城市相比元素Cd,Co和Mn处于较高污染水平,Pb处于较低污染水平；与国外发达国家城市如墨西哥城,洛杉矶和多伦多相比,郑州市高新区PM2.5中元素含量远大于这些城市。有害金属Cd和As浓度分别为10.6和21.4ng/m3超过EU标准限值5和6ng/m3；V的平均浓度为3.9ng/m3, WHO规定的日均限值为1ng/m3,超标率为97%；Pb的浓度未超过国家标准。各元素的季节变化明显：Fe、Ca、Al、Mg等地壳元素在春季出现最高值,可能与郑州春季风沙天气有关；K、Na、Mn、Co、Zn、V、Cr、As、Se、Sr、Cd、Pb等元素最高值出现在冬季,可能与是生物质、煤的烧燃有关；元素的最低浓度大多出现在夏季。(3)相关性分析表明：Ca、Al、Fe、Mg、Sr两两之间的相关系数在0.82～0.93之间,表明其可能来自土壤扬尘；K元素与Se、Na、As相关性较高,表明其可能来自于燃烧源；Zn与Pb、Cu、Cd、Se相关性较高,可能来源于工业过程或交通源。富集因子分析表明：PM25中金属富集因子大于100的是Cd、Pb、Zn、 As和Cu,且满足Cd> Pb> Zn> As> Cu的规律,表明其主要受人为源的影响。因子分析研究表明：土壤扬尘、生物质、燃煤、冶金、燃油和交通是该地区PM2.5中金属元素的主要来源。用PMF(正交矩阵分解)对6种水溶性离子,金属元素和EC/OC数据进行源解析的结果表明：二次气溶胶,土壤扬尘和燃煤对PM2.5的贡献为26.7%,25.9%和19.1%,是PM2.5的主要来源。其它来源还有生物质燃烧+燃油源,机动车和燃煤除外的其它工业,其贡献分别为是16.3%、9.6%和2.3%。更多还原

【Abstract】 Zhengzhou is a developing region that is heavily polluted with high levels of particle air pollution, which take a negative effect on environment and climate. Particulate matter can carry plenty harmful substances with it such as heavy metals, which are known or suspected to cause adverse health effect on humans. It is therefore, highly desirable to understand the particle matter pollution especially PM2.5and the metals it carried with in Zhengzhou. In this study, fine particulate matter (PM2.5) was collected with a high volume sampler TE-6070D in an industrial district of Zhengzhou from Jan.2010to Jan.2011.19elements of the samples were determined by Agilent-7500cx ICP-MS to study the characteristics and sources of PM2.5in Zhengzhou. The results showed that:(1) The average concentrations of PM2.5is175.4μg/m3, which is significantly higher than the assessent threshold of EU (25μg/m-3;European Commission), WHO (10μg m-3), and USA (15μg m-3), The seasonal variability of PM2.5is apparent, the average concentrations of PM2.5arel79.6,131.6,185.5and210.1μg/m3for spring, summer, autumn and winter, respectively.(2) The concentrations of the19species measured follow the order of Fe> K> Ca> Al> Zn> Mg> Pb> Mn> Na> Ba> Cu> As> Cr> Sr> Se> Cd> V> Ni> Co. The concentrations of Co, Cd andMn measured in this study are high, whereas Pb is low in comparison with other cities in China; but most elements are much higher than the average levels in Mexico City, Los Angles and Toronto. Toxic mentals Cd and As concentration exceed EU Air quality Framework Directive. In the case of V, the proposed24-h concentration is1ng/m3. A value be exceeded at the rate of97%during the sampling campaign. Annual average concentrations of Pb were found below the limit values at all samples. The seasonal variability of metal concentration shows that high values of crust elements such as Fe, Ca, Al, Mg and Ba appear in spring when sandstorm weather usually occurs, which can bring soil dust rich in Ca, Fe and Al; high levels of K, Na, Mn, Co, Zn, V, Cr, As, Se, Sr, Cd and Pb appeared in winter, while low levels of most elements were measured in summer.(3) Correlation Analysis shows that Al, Ca, Mg, Fe and Sr have Spearman R’s of0.82-0.93between each other, indicating the existence of a common emission source: soil dust; K was correlated with Se, Na and As, they may come from combustion sources; Pb, Cu, Cd and Se are correlated strongly with Zn as they aretypically anthropogenic emissions from some industrial and traffic process. Enrichment Factor (EF) Analysis shows that the EF values for heavy metals such as Cu, As, Zn, Pb and Cd were much higher than100, it clealy indicates that they are mainly originated from anthropogenic sources. Factor analysis on the chemical composition of PM2.5shows that soil dust, biomass and coal fuel combustion, metal-working industry, fuel and traffic are the main sources of the elements in the research region. Samples were also analyzed by PMF (Positive Matrix Factorization) to find the main sources of PM2.5, the statistics of soluble ions, elements and EC/OC were included in PMF analysis. The result shows that secondary aerosol, soil dust and coal combustion are the major sources of PM2.5which contribute26.7%,25.9%and19.1%of total PM2.5mass concentration. The contributions of other sources are biomass burning+Oil combustion16.3%, vehicle9.6%, industrial2.3%.更多还原