【作者】 庞博；

【导师】 张银龙；

【作者基本信息】 南京林业大学 ， 环境科学， 2010， 硕士

【摘要】 本文选取南京市5个功能区,分别收集各功能区5种典型绿化树种的叶面尘与地面尘,测定了叶面尘与地面尘的粒径分布和重金属含量,并以此对重金属的生态风险进行评价,最后进行了叶面尘与地面尘所含重金属元素之间的相关性和源解析研究。本文主要研究结果如下:(1)叶面尘与地面尘粒径同为单峰分布,且叶面尘粒径小于地面尘。商业区和工业区中叶面尘和地面尘所含细颗粒物较多。(2)Cr、Cu、Pb、Zn含量随月份变化具备较强的规律性,都在5月或9月含量较高,7月含量最低;商业区和工业区是叶面尘与地面尘重金属含量最高的地区,Cu在工业区污染最严重,Pb和Zn在商业区污染最突出。潜在生态风险评价表明,叶面尘的生态危害大于地面尘,重金属生态风险最大的为商业区,其次为工业区,两区已达到中等生态风险等级。(3)Pearson相关分析发现叶面尘与地面尘中Cr、Cd、Pb、Zn、Cu、Mn和Ni7种重金属呈现较大相关性,尤以Cr、Pb、Zn、Cu的相关性最显著。(4)由叶面尘与地面尘的源解析得出工业燃煤、交通源和城市建材源是叶面尘的主要来源,3种尘源对总体的贡献率达到56.18%;交通污染、垃圾焚烧和工业源是地面尘的主要来源,3种尘源对总体的贡献率达到76.72%。更多还原

【Abstract】 We have taken Nanjing as a case study and chosen five different urban areas with typical plots of trees, including foliar dusts and surface dusts in same areas. The particulate size of foliar dusts and surface dusts were determined with a Laser Particle Sizer, the total concentrations of heavy metals in dusts were determined with ICP-AES, on which the potential risk of heavy metals was evaluated, and then the correlation of various heavy metals was analyzed and the sources of the dusts were discussed. Since two dusts have connections but also differences with each other, the dust pollution status of different unban areas can be indicated by the research of them and that can provide consultations on the management of dust.The main conclusions of this study can be summed up as follows:(1)The grain size distribution of foliar dusts and surface dusts obeyed the normal distribution with single-apices. The size of two dusts mainly concentrated in[10-50]μm, the particulate size of foliar dusts was finer than surface dusts. Potential ecological risk of dusts in commercial area and industrial area were severe because of the high percentage of fine particulates.(2)The monthly and spatial variance of heavy metals in foliar dusts and surface dusts showed that the contents of Cr, Cu, Pb, Zn abided similar regularity, the contents of them were highest in May or September, and lowest in July; The contents of heavy metals in commercial and industrial areas were highest, and the contents of Cu were highest in industrial area, while the contents of Pb and Zn were highest in commercial area, the dusts pollution in traffic hub area and street multi-layer greening area were milder than other areas, the foliar dust pollution in educational and residential area was conspicuous, which should pay attention on it. Potential ecological risk assessment showed that ecological risk of foliar dusts was more serious than surface dusts,the dusts pollution of commercial and industrial areas in Nanjing were at alarming risk, have all reached the moderate risk level.(3) Pearson correlation analysis found that foliar dusts and surface dusts had relatively high correlation by the analysis ofCr, Cd, Pb, Zn, Cu, Mn and Ni, in which Cr, Pb, Zn, Cu had highest correlation, all those indicated foliar dusts and surface dusts had similar sources.(4) The source apportionment of foliar dust and surface dust illustrated that Coal-fired in industry,the traffic dust and the city building materials dust were main sources of the foliar dust, the contribution rate of these three kinds of dust sources has achieved 56.183%; The traffic pollution, waste incineration and industry dust were main sources of the surface dust, the contribution rate of these three kinds of dust sources has achieved76.715%.更多还原