运用单颗粒气溶胶质谱技术研究上海大气重金属(Zn,Cu)污染  

Single Particle Mass Spectrometry of Zinc and Copper-Containing Aerosols in Shanghai

作　　者：张雅萍[1] 杨帆[1] 汪明明[1] 王笑非[1] 陈宏[1] 杨新[1] 

机构地区：[1]复旦大学环境科学与工程系,上海200433

出　　处：《复旦学报（自然科学版）》2010年第1期51-59,65,共10页Journal of Fudan University：Natural Science

基　　金：教育部博士点基金资助项目(20070246026)

摘　　要：使用气溶胶飞行时间质谱仪（ATOFMS）对2007年的8月（夏季）和2008年2～3月（冬季）上海大气中的含重金属乙，Cu颗粒物进行分析．结果表明：冬季的重金属污染比夏季严重，在单位时间内冬季观测到的含铜颗粒物数目是夏季的2倍，夏季没有观测到含锌颗粒物，冬季观测到大量的含锌颗粒物．运用自适应共振理论神经网络算法（ART-2a）对含重金属颗粒物数据进行了质谱分类分析．结果表明，含重金属颗粒物的化学成分都包括大量的有机碳、硫酸盐、硝酸盐和元素碳．夏季含铜颗粒物中同时含有氯．部分颗粒含有两种或多种重金属元素如Pb和Cu，或Pb和办和Mn，或Cu和V等．从粒径特征上来看，粒径最小的是含有元素碳的颗粒物，粒径分布最大值在0．4μm，其次是含有有机碳一硫酸盐，硝酸盐，氯的颗粒物，粒径分布最大值在0．5～0．6μm粒径较大的是多种金属组合的颗粒物，最大值在1μm左右．根据单颗粒质谱特征对含重金属颗粒物进行了源解析：夏季ATOFMS采集的含重金属颗粒物主要来自垃圾焚烧和重油燃烧；冬季ATOFMS采集的含重金属颗粒物主要来自垃圾焚烧和煤炭燃烧以及金属冶炼．Aerosol time of flight mass spectrometry （ATOFMS） determines aerodynamic size （in the 0. 1-2. 5μm range） and chemical composition of single particles. Zinc （Zn） and copper （Cu） in individual aerosol particles were measured using ATOFMS in August of 2007 （summer）, February and March of 2008 （winter） in Shanghai, China. In general, heavy metal pollution in winter was more severe than in summer. Specifically, number concentration of Cu in winter was two times higher than that in summer. No zinc containing particles were observed in summer while a large number of zinc containing particles existed in winter. Using the ART-2a neural network algorithm, these fine Zn and Cu containing particles were classified into several main classes by their mass spectral patterns. All observed heavy metal containing particles contained sulfate, nitrate organic carbon and elemental earbon. A part of Cu containing particles in summer contained chlorine. The combinations of heavy metal, such as Pb and Cu, Pb and Zn and Mn, Cu and V, also existed in heavy metal containing particles. For size distribution, particles containing elemental carbon are the smallest particles, peaked at 0. 4μm. The size of the particles containing organic carbon-sulfate, nitrate and chlorine, peaked at 0. 5 -0. 6μm. Particles containing multiple heavy metals are relative larger, peaked at 1 μm. Based on the temporal variation of number density, chemical composition and the correlation between different chemical species, several major emission sources were identified. In summer, most heavy metal containing particles were attributed to waste incineration and oil combustion. In winter, heavy metal containing particles were assigned to waste incineration, coal combustion, and metallurgical processes.

关 键 词：上海 大气气溶胶 锌 铜 气溶胶飞行时间质谱仪 

分 类 号：X131.1[环境科学与工程—环境科学]