保定市日间、夜间大气PM_(2.5)中无机组分的特征及来源分析  

Characteristics and source analysis of inorganic components in PM_(2.5) samples collected during daytime and night in Baoding City

作　　者：王永慧[1] 刘芃岩[1] 于泊蕖[1] 刘庆学[2] 王心宇[3] 姜云军[2] 

机构地区：[1]河北大学化学与环境科学学院,保定071002 [2]河北省地矿中心实验室,保定071000 [3]北京市疾病预防控制中心,北京100013

出　　处：《环境化学》2017年第9期1941-1948,共8页Environmental Chemistry

基　　金：国家自然科学基金(21377033);河北省教育厅重点项目(ZD20131046)资助~~

摘　　要：以超声萃取/ICP-MS、微波消解/IC(离子色谱)检测技术对保定市(2016年1—4月)PM_(2.5)样品上的水溶性离子、无机元素等无机成分进行分析,并通过PM_(2.5)质量浓度、水溶性离子含量、无机元素相关性等对PM_(2.5)上无机污染物来源进行解析.结果发现:水溶性离子12种,占PM_(2.5)质量60%以上;除NO-2外,所有水溶性离子夜间浓度高于日间,其中NO-3的夜间最低浓度是日间的12倍,SO_4^(2-)、NH_4^+的夜间浓度也是日间的近2倍,此外所有样品中二次离子NO_3^-、SO_4^(2-)、NH_4^+含量最高,分别占水溶性离子的21.1%—60.5%、16.9%—40.0%、2.0%—24.1%;无机元素34种,其中重金属元素12种,其余为地壳、稀有金属及放射性元素,其中除地壳元素日间浓度高于夜间外大部分无机元素夜间浓度高于日间.5种有毒元素中,As超标率大于60%,Pb、Hg均未超出国家环境空气质量标准限值.总Cr日夜浓度分别为2.6—9.0、3.2—12.9 ng·m^(-3),超标率也大于60%.结果显示保定市大气PM_(2.5)上水溶性离子主要来源于机动车尾气排放,其次为燃煤,生物质燃烧及烹饪也有一定的贡献;无机元素主要来源于建筑及土壤扬尘,其次为燃煤及机动车等排放.PM2.5 samples collected in Baoding City during a heavy haze period （Jan. to Apr. ） were analyzed by ultrasonic extraction/inductively coupled plasma mass spectrometry （ICP-MS） and microwave digestion/ion chromatography （IC）. The main inorganic components such as the water soluble ions （WSIs） and inorganic elements （IEs） were measured. Sources of the inorganic components were investigated according to PM2.5 mass concentration, WSIs content and the correlation of IEs in PM2.5 samples. The results showed that 12 WSIs were detected, which accounts for more than 60% of total PM2.5. Except for NO2-, all the WISs＇ concentrations in the PM2.5 samples collected at night were higher than those collected at daytime, and the lowest concentration of NO3 in the night samples was 12 times that of the daytime samples. And the concentrations of SO4 - and NH4 were nearly twice as much as those of the day samples. In addition, the secondary WSIs NO3-, SO4 2-, NH4 were the major ionic compounds in all samples, which respectively contributed 21.1%-- 60.5%, 16.9%--40.0%, and 2.0%--24.1% to the total WSIs. In addition, 34 IEs were detected, containing 12 heavy metal elements. The others were earth＇s crust, rare metals and radioactive elements.In addition, except crustal elements, most of the inorganic elements＇ concentrations were higher in the night samples. Heavy metal elements Pb, Cd, Hg didn＇t exceeded the national ambient air quality standards, but more than 60% of As in samples exceeded the standard. The total concentrations of Cr in day and night were 2.6--9.0 and 3.2--12.9 ng· m-3, also exceeded the standard by more than 60%. Finally the results showed that WSIs in PM2.5 were mainly from motor vehicle exhaust emissions, secondly coal combustion, biomass construction and cooking process. IEs mainly came from building and soil dust followed by mixed coal and motor vehicle emissions.

关 键 词：PM2.5 水溶性离子 无机元素 源分析. 

分 类 号：X513[环境科学与工程—环境工程]