广州市大气颗粒物PM_(2.5)显微形貌特征和来源解析  

Preliminary Study on the Microscopic Morphology and Chemical Composition,and Its Source of PM_(2.5) in Guangzhou

作　　者：周莉[1] 石贵勇[1,2] 付宇[1] 关瑶[1] 陈来国[3] 

机构地区：[1]中山大学海洋学院,广东广州510275 [2]广东省海洋资源与近岸工程重点实验室,广东广州510275 [3]环境保护部华南环境科学研究所,广东广州510655

出　　处：《岩矿测试》2016年第3期302-309,共8页Rock and Mineral Analysis

基　　金：国家自然科学基金资助项目(41373012);广州市科信局应用基础专项节能环保项目(2013J4100115)

摘　　要：PM2.5是近年来影响我国城市大气环境的首要污染物,其成因机制复杂.本文采用扫描电镜和ICPMS研究了广州市大气颗粒物PM2.5的显微形貌及其化学组成特征,并应用富集因子法进行源解析.结果表明,PM2.5的颗粒形态以无定形态为主;主要物质表现为含Fe、Mg、Al、K、Na的硅酸盐组合,具有道路扬尘、建筑施工排放等一次粒子特征;单个无定形颗粒物能谱表现出硫酸盐＋硝酸盐的组合特征,为汽车尾气所排放的前体污染气体NOx和SO2进入大气环境中,在特定的物理化学条件下通过成核作用发生相态改变所形成的二次粒子.PM2.5中高度富集Cd、Se、Zn、Cu、Pb、As等重金属,异常富集的Br主要为当地普遍使用的阻燃剂十溴联苯醚和拆解电子垃圾所致,稀土元素的浓度在0.022～0.582ng/m3之间,具有重稀土元素富集的特征.反映出广州市PM2.5颗粒物的组成既有一次粒子,也有二次粒子,物质来源具有多重性.PM2. 5is the primary pollutant which has influenced the urban atmospheric environment in recent years,and its genetic mechanism is complicated. The microscopic morphology and trace element concentration of PM2. 5in the Guangzhou urban area were determined by Scanning Electron Microscope and Inductively Coupled Plasma-Mass Spectrometry,respectively. The enrichment factor method was adopted to constrain the source of PM2. 5. The results show that PM2. 5mainly occurs as amorphousness fine particles. A silicate combination containing Fe,Mg,Al,K and Na is the main chemical composition of PM2. 5,characterized by the first fine particles from road dust and buildings. An energy spectrum diagram of single amorphous particle shows the combination characteristics of sulfate and nitrate.These particles may have been secondary fine particles formed from pollution gases of SO2 and NOxfrom automobile exhaust in the atmospheric environment,through the nucleation induced phase behavior change under specific physical and chemical conditions. Heavy metals were highly enriched in PM2. 5,including Cd,Se,Zn,Cu,Pb,and As. Local widespread use of deca bromine biphenyl ether as a flame retardant and a large number of E-waste dismantling are the main factors for abnormal enrichment of Br in the fine particles. The concentration of rare earth elements ranges from 0. 022 to 0. 582 ng / m3,with the relative enrichment of heavy rare earth elements in PM2. 5.These features indicate that the composition of PM2. 5in the Guangzhou urban area are not only made up of primary particles,but also made up of secondary particles,characterized by multiple sources.

关 键 词：PM2.5 显微形貌特征 物质组成 源解析 扫描电镜 电感耦合等离子体质谱 

分 类 号：O657.63[理学—分析化学]