北京大气颗粒物中多环芳烃浓度季节变化及来源分析  

SEASONAL VARIATION AND SOURCE IDENTIFICATION OF POLYCYCLIC AROMATIC HYDROCARBONS(PAHs) IN AIRBORNE PARTICULATES OF BEIJING

作　　者：王英锋[1] 张姗姗[1,2] 李杏茹[1,2] 郭雪清[1] 王跃思[2] 

机构地区：[1]首都师范大学化学系分析测试中心,北京100048 [2]中国科学院大气物理研究所,LAPC,北京100029

出　　处：《环境化学》2010年第3期369-375,共7页Environmental Chemistry

基　　金：国家重点基础研究发展计划(973计划)(2007CB407303);中国科学院知识创新工程重大研究项目(KZCX1-YW-06-01);LAPC国家重点实验室开放课题资助项目

摘　　要：使用大流量滤膜采样器,从2006年9月至2007年8月,每周同时采集北京城市大气可吸入颗粒物(PM10)和细粒子样品(PM2.5)各一次,二氯甲烷超声抽提-气相色谱/质谱分析了17种多环芳烃(PAHs)浓度,结果表明,春、夏、秋、冬四季北京大气PM10和PM2.5中PAHs总量分别为63.8±44.6ng.m-3、43.2±4.5ng.m-3、84.7±108.3ng.m-3、348.0±250.0ng.m-3和54.7±17.3ng.m-3、40.3±8.6ng.m-3、66.1±81.5ng.m-3、337.7±267.2ng.m-3;约有70%的PAHs存在于细粒子PM2.5中,其质量浓度有明显季节变化,冬季>秋季>春季>夏季;颗粒物中PAHs主要以4、5、6环存在,其中4环以上占79.4%.源解析表明,北京大气颗粒物中的PAHs主要来自燃煤,同时汽油、柴油燃烧排放也不能忽略.结合气象要素分析,温度升高和太阳辐射增强易造成多环芳烃挥发和反应,湿沉降有利于多环芳烃随颗粒物清除.Polycyclic aromatic hydrocarbons（PAHs）are primary persistent organic pollutants and have adverse effects on human health.Continuous monitoring of PAHs in PM10and PM2.5 was carried out once a week at an urban site in Beijing during September 2006 to August 2007 by using sampler of large flow capacity.PAHs of 17 species were analyzed with dichloromethane ultrasonic extraction-GC/MS technique.The results showed that total concentrations of PAHs in PM10were 63.8±44.6,43.2±4.5,84.7±108.3 and 348.0±250.0 ng·m-3 for spring,summer,autumn and winter,respectively.Total concentrations of PAHs in PM2.5were 54.7±17.3,40.3±8.6,66.1±81.5 and 337.7±267.2ng·m-3 for the above seasonal sequence.About 70% PAHs of PM10is in PM2.5.The highest concentration of PAHs appears in winter time,followed by autumn,spring and summer.The ratio for PAHs with more than 4 rings to total PAHs concentration is nearly 80%,which indicates PAHs of 4-,5-and 6-ring were the main components in airborne particulates of Beijing.Simultaneously,source identification technique revealed coal burning was the main emission source of PAHs.Gasoline and diesel oil combustion can＇t be ignored either.The PAHs in particulate will decrease when the air temperature,ultraviolet radiation and precipitation increase,which lead to volatilization,photo-decomposition and removal,respectively.

关 键 词：PM10 PM2.5 PAHS 北京 季节变化 来源. 

分 类 号：X513[环境科学与工程—环境工程]