基于GAC–雾化器–AMS联用的PM2.5中水溶性有机物的在线测量和来源解析

项目名称： 基于GAC–雾化器–AMS联用的PM2.5中水溶性有机物的在线测量和来源解析

项目编号： No.21277003

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 环境科学、安全科学

项目作者： 黄晓锋

作者单位： 北京大学

项目金额： 80万元

中文摘要： 水溶性有机物(WSOM)是大气PM2.5的重要组分，对颗粒物吸湿性具有显著贡献，进而影响成云过程，并可能在我国城市频繁发生的灰霾天气中起到重要作用。以往国内外对WSOM化学结构的测量几乎都是离线的，时间分辨率低，不能反映WSOM在大气中的快速迁移转化规律。本项目拟探索性地将GAC(气体和气溶胶在线收集系统)、雾化器、AMS(高分辨气溶胶质谱仪)进行联用，实现对PM2.5中WSOM总量与化学结构的同步在线测量；并以深圳为例进行系统的城市和乡村大气四季加强观测，利用高时间分辨的多维数据揭示WSOM浓度水平、质谱结构、元素组成和粒径分布等理化性质精细的时空演变特征与影响因素；应用新型的AMS-PMF(正向矩阵因子解析)源解析技术有效地量化生物质燃烧和二次有机气溶胶等不同来源对WSOM的贡献率及其变化特征，为全面掌握我国大气PM2.5污染特征和环境影响并采取有效的控制对策提供可靠的科学依据。

中文关键词： 细颗粒物；水溶性有机物；气溶胶质谱仪；在线观测；二次有机气溶胶

英文摘要： Water-soluble organic matter (WSOM) is an important component in atmospheric PM2.5, contributing significantly to aerosol hygroscopicity and thus affecting the cloud formation processes. WSOM may also play a key role in the formation of frequent hazy days in Chinese cities. Previous chemical characterization of WSOM was mostly offline, with low time resolution, and thus not able to provide information about the fast variation of WSOM in the atmosphere. In this proposal, we will establish a new method to online measure the concentration and chemical structure of WSOM in PM2.5, with the conjunction of gas and aerosol collector (GAC), nebulizer, and aerosol mass spectrometer (AMS). This newly developed system will be deployed in Shenzhen, China, to measure WSOM in urban and rural atmospheres in four seasons. The obtained high time resolution dataset will be used to analyze the tempo-spatial variations of WSOM concentrations, mass spectrum, elemental composition, and size distribution. The new AMS-PMF (positive matrix factorization) method will be used to perform source apportionment of WSOM for understanding the quantitative contributions of biomass burning and secondary organic aerosol. The results obtained with such study will be helpful for evaluating the PM2.5 pollution and its environmental effects in China an

英文关键词： PM2.5；Water-soluble organic matter；Aerosol mass spectrometer；On-line measurement；Secondary organic aerosol