2018年成都市PM_(2.5)中水溶性无机离子污染特征及来源解析  

Characteristics and source apportionment of water-soluble ions in PM_(2.5) during 2018 in Chengdu

作　　者：陈耶沙 叶芝祥[1] 袁小燕 郭生鑫 CHEN Yesha;YE Zhixiang;YUAN Xiaoyan;GUO Shengxin(Chengdu University of Information Technology,College of Resources and Environment,Chengdu,610000,China;Sichuan Academy of Environment Sciences,Chengdu,610041,China)

机构地区：[1]成都信息工程大学资源环境学院,成都610000 [2]四川省生态环境科学研究院,成都610041

出　　处：《环境化学》2022年第6期2062-2074,共13页Environmental Chemistry

摘　　要：为了探究成都市PM_(2.5)水溶性无机离子的污染特征与来源贡献,于2018年1月1日—12月31日利用高分辨率的MARGA对PM_(2.5)组分展开在线监测,结合同一点位的气态污染物、气象参数监测数据进行分析.结果表明,水溶性无机离子与PM_(2.5)具有相同的月变化趋势,水溶性无机离子月均浓度为10.35-39.60μg·m^(-3),在PM_(2.5)中的占比为31%—51%,水溶性无机离子是PM_(2.5)的重要组成部分.NO_(3)^(-)在水溶性无机离子中月均占比以12月最高,8月最低,SO_(4)^(2-)刚好与之相反.大气长期处于富氨状态,二次离子主要以(NH_(4))_(2)SO_(4)、NH_(4)NO_(3)、NH_(4)Cl的形式存在,SOR在冬季12月与夏季8月分别出现高值0.61与0.5,但NOR只在冬季出现高值且均低于SOR,SO_(2)的二次转化率更高,且两者受到的影响因素不同.通过对不同污染水平及不同湿度下水溶性无机离子的污染特征分析发现在污染加重或湿度增大时,NO_(3)^(-)在水溶性无机离子中的占比最高且上升趋势明显,SO_(4)^(2-)在水溶性无机离子中占比却出现了不同程度的下降,结合离子的存在形式及二次转化特点分析发现有大量的NO_(3)^(-)生成,同时与NH_(4)^(+)结合生成二次无机盐使颗粒物浓度升高.利用PMF模型解析发现成都市的水溶性无机离子主要来源为机动车排放源、化石燃料燃烧源、生物质燃烧源以及扬尘源.To understand the pollution characteristics and sources of water-soluble inorganic ions in PM_(2.5) in Chengdu,PM_(2.5) samples and its chemical composition were serially online monitored by using MARGA from January 1 to December 31,2018 continuously,and combed with environmental monitoring data and meteorological monitoring data at the same point,composition characteristics of water-soluble inorganic matter were analyzed.The results show that the water-soluble inorganic ions have the same monthly variation trend as PM_(2.5).The average monthly concentration of water-soluble inorganic ions range from 10.35—39.60μg·m^(-3),accounting for 31%—51%in PM_(2.5),indicating that water-soluble inorganic ions are the major components of PM_(2.5).The monthly average proportion of NO_(3)^(-) in water-soluble inorganic ions is the highest in December and the lowest in August,while that of SO_(4)^(2-) is just the oppsiote.The atmosphere is rich in ammonia,and the secondary ions mainly exist in the forms of(NH_(4))_(2)SO_(4)、NH_(4)NO_(3)、NH_(4)Cl.The high value of SOR is 0.61 in December and 0.50 in August,However,NOR is only high in winter and lower than SOR,the secondary conversion rate of SO_(2) is higher,and the two are affected by different factors.After the analysis of the pollution characteristics of water-soluble inorganic ions at different pollution levels and different humidity,it is found that the proportion of NO_(3)^(-) water-soluble inorganic ions is the highest and the increasing trend is obvious when the pollution or the humidity increases,while the proportion of SO_(4)^(2-) in watersoluble inorganic ions deacreased to different degrees.Analysis of the existing forms of ions and the characters of secondary conversion,it is found that a large amount of NO_(3)^(-) is generated by transformation,at the same time,it combines with NH_(4)^(+) to generate secondary inorganic salts,which increased the concentration of particulate matter.Based on PMF model analysis,it is shown that the main sources of water-solu

关 键 词：成都市 PM_(2.5) 水溶性无机离子 污染特征 来源解析 

分 类 号：X513[环境科学与工程—环境工程]