成都市城区大气细颗粒物水溶性离子污染特征  

Characterization of water-soluble ions pollution of atmospheric fine particles in Chengdu City

作　　者：李欣悦 张凯山[1] 武文琪 邓林俐 殷子渊 向锌鹏 孟祥瑞[1] 庞凯莉 朱怡静 马帅[1] LI Xin-yue;ZHANG Kai-shan;WU Wen-qi;DENG Lin-li;YIN Zi-yuan;XIANG Xin-peng;MENG Xiang-rui;PANG Kai-li;ZHU Yi-jing;MA Shuai(College of Architecture and Environment,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学建筑与环境学院,四川成都610065

出　　处：《中国环境科学》2021年第1期91-101,共11页China Environmental Science

基　　金：国家自然科学基金资助项目(41877395);四川省重大科技专项(2019YFS0498)。

摘　　要：为了解成都市城区大气细颗粒物水溶性离子污染特征,在成都市城区四季采集PM2.5有效样品共计102个,测得颗粒物质量浓度以及水溶性离子质量浓度(NH4^+、Ca^2+、Na^+、Mg^2+、K^+、F^-、NO3^-、SO4^2-、Cl^-),并分析其浓度变化特征,重点关注二次无机离子的污染特征及形成影响.结果表明,成都市城区水溶性离子与大气细颗粒物的污染浓度变化基本一致,其中二次无机离子(NH4^+、NO3^-、SO4^2-)是离子中最主要的组成部分,占总水溶性离子浓度的84.8%.大气细颗粒物春秋冬三季为酸性,其原位PH值分别为1.9、2.6和2.0.城区硫酸盐和硝酸盐化学特性存在差异,硫酸盐主要表现为非均相反应过程中形成的NH4HSO4,并主要受区域传输过程的影响;硝酸盐主要表现为均相反应过程形成的NH4NO3,并主要受局地排放的影响.In order to understand the characteristics of water-soluble ion pollution of atmospheric fine particles in the urban area of Chengdu,a total of 102 PM2.5 samples were collected in the urban areas of Chengdu in four seasons.Mass concentrations of particles matter(PM)and its water-soluble ions(NH4^+、Ca^2+、Na^+、Mg^2+、K^+、F^-、NO3^-、SO42^-、Cl^-)were measured and analyzed to characterize its seasonal,with special attentions to characteristics and formation of secondary ions.The results showed that concentration changes of water-soluble ions and atmospheric fine particles in Chengdu’s urban area generally followed the same pattern.Secondary inorganic ions(NH4^+、NO3^-、SO4^2-)were the main components of water-soluble ions in PM,accounting for 84.8%.Atmospheric fine particles appeared to be acidic in Spring,Autumn,and Winter,and their in-situ PH values were 1.9,2.6 and 2.0,respectively.Sulfate and nitrate in the atmospheric PM exhibited differences in its chemical characteristics.For example,the dominating form of sulfate was NH4HSO4,which mainly resulted from heterogeneous reaction processes and was heavily affected by the regional atmospheric transportation;while the dominating form of nitrate was NH4NO3,which mainly resulted from homogeneous reaction processed and was heavily affected by local emissions.

关 键 词：PM2.5 水溶性离子 二次无机盐类 污染特征 

分 类 号：X513[环境科学与工程—环境工程]