【作者】 陈琳；

【导师】 翟云波；

【作者基本信息】 湖南大学 ， 环境工程， 2010， 硕士

【摘要】 本文使用TH-150C中流量采样器对长沙市夏季和秋季大气颗粒物(TSP)样品分别进行采样,使用重量法测定颗粒物的质量浓度,并使用BCR和Tessier形态分析法对TSP中的重金属元素的浓度和形态分布进行了定量分析研究。结果表明长沙市夏季大气颗粒物污染较为严重,平均浓度值为220.7±42μg／m3,超过国家二级标准(200μg／m3),但四个采样点均未超出国家三级标准(300μg／m3)。从站点来看,TSP浓度高低顺序为：经开区>开福区>高开区>马坡岭；颗粒物中重金属含量高,浓度高低顺序为：Zn>Pb>Cu>Mn>Cd。从站点分布来看,重金属总浓度值大小顺序为：经开区>马坡岭>高开区>开福区,表明TSP浓度与重金属浓度关系不大。从四个站点来看,重金属的形态分布比较相似,但在含量方面还是有很大的不同；从污染因子计算中可以得出：重金属的迁移大小为：Cu>Zn>Cd>Pb>Mn；从因子分析中可以得出,这五种重金属元素主要来自于人为污染源,长沙市TSP中重金属元素在3个主要影响因子占总成因率达85%。长沙市秋季大气颗粒物污染较为严重,雨花区和火车站的TSP浓度超过大气环境质量年平均浓度二级标准200μg／m3,但三个采样点均没有超过年平均浓度三级标准；颗粒物中重金属含量高,Zn和Pb的浓度远远高于Cu和Cd的含量,其中Zn的平均浓度为2.528μg／m3,Pb为2.347μg／m3,Cu为0.187μg／m3,Cd为0.002μg／m3；颗粒物重金属的形态分析表明Cu的可生物利用态含量最高,Zn、Pb、Cd的可生物利用态含量稍低,除火车站Pb和Zn,其余的均超过了50%；在生物有效性评价中,Cu和Cd的生物有效性要大于Zn和Pb。本文还采用扫描电镜和其配套的能谱分析仪对长沙市TSP的微观形态特征进行分析研究。研究表明：硅铝酸盐类颗粒是主要成分,可能的来源是土壤扬尘和燃煤过程的一次粒子排放；长沙市TSP主要来自于土壤的扬尘、燃烧飞灰和石膏等含Ca的矿物颗粒,并且颗粒物由两种以上矿物组成；长沙市TSP中细颗粒数比粗颗粒数要多,不规则形状较多。更多还原

【Abstract】 The TSP samlpes being sampled in summer and autumn respectively of Changsha by the TH-150C middle volume total suspended particulates (TSP) samplers were used to analyse the particulate concentrations by the weight method and the speciation analysis of heavy metal element of TSP were carried out using the BCR and Tessier speciation method. The results show that the atmospheric particulate pollution is serious hvaing a average concentration value of 220.7±42μg/m3, more than the national secondary standard (200μg/m3), but none of the four sampling sites exceeding the national thirdary standard (300μg/m3). The concentration of TSP is in the order of:Jinkai>Kaifu> Gaokai> MaPoling and that of heavy metals is:Zn> Pb> Cu> Mn> Cd. The total concentration of heavy metals in different spots is in the order of:Jinkai> Ma Poling> Gaokai> Kaifu, showing that the concentration of TSP has little relationship with that of heavy metal. In four sites, the speciation of heavy metals is similar, but in content is quite different. Pollution factor calculation results show that the metal migration size:Cd> Cu> Zn> Mn> Pb; factor analysis results show that the five kinds of heavy metals are from human activities and in the three main factors causing the total rate of 85%. Air particle pollution is more serious in autumn of Changsha and the concentration of TSP exceeds the average concentration of atmospheric environmental quality standard 2 (200μg/m3) at Yuhua District and the railway station, but none of the three sampling points over the average concentration of thirdary standard; and particles have high content of heavy metals, the concentrations of Zn and Pb were larger than those of Cu and Cd, with the average concentration of Zn was 2.528μg/m3, Pb was 2.347μg/m3, Cu was 0.187μg/m3 and Cd was 0.002μg/m3.According to the results of chemical speciation analysis, Cu has the highest content of bioavailable state while Zn, Pb, Cd have lower levels of bioavailable state, and except Pb and Zn of the railway station, all of these are over 50%. The order of comparative mobility and bioavailability of heavy metals is: Cu>Cd>Zn>Pb. It is also analyzed the microstructure of TSP by scanning electron microscope and its supporting spectrum analyzer. Research shows that:silicon aluminum acid salt particles are the main ingredients coming from the source of coal dust and the process of soil particle emission. The TSP major come from dust, fly ash and mineral particles such as gypsum, and the number of TSP of fine grain number is more than the number of coarse and more irregular shape having two or more mineral composition.更多还原