某典型交通路口大气颗粒物(PM10和PM2.5)中多氯联苯季节变化特征  

Seasonal Variations of Polychlorinated Biphenyls(PCBs)from Atmospheric PM10 and PM2.5 at the Traffic Crossing

作　　者：孙俊玲 SUN Junling(Shandong Provincial Vehicle Emission Administration Center,Jinan 250101,China)

机构地区：[1]山东省机动车排气污染监控中心,山东济南250101

出　　处：《中国环境监测》2020年第3期66-73,共8页Environmental Monitoring in China

基　　金：国家自然科学基金资助项目(91743206,21777186,41676183)。

摘　　要：应用同位素稀释高分辨率气相色谱-高分辨质谱(HRGC-HRMS)联用技术对北京市北四环典型交通路口大气颗粒物PM10和PM2.5中多氯联苯(PCBs)进行了监测,分析了PCBs浓度水平、单体组成特征、粒径分布规律和季节变化趋势。结果表明:大气颗粒物PM10和PM2.5样品中19种PCBs浓度和毒性浓度(TEQ,以世界卫生组织毒性当量因子WHO-TEF计)分别为1.05~13.83 pg/m^3(平均值为6.66 pg/m^3)和1.24~15.18 fg/m^3(平均值为6.84 fg/m^3)、0.80~8.51 pg/m^3(平均值为4.32 pg/m^3)和0.88~13.40 fg/m^3(平均值为5.90 fg/m^3),PM10和PM2.5中PCBs的单体分布模式相似,浓度丰度最大的是PCB-28和PCB-209,而对毒性当量贡献最大的是PCB-126。PCBs浓度季节变化明显,冬、春季明显高于夏、秋季。PCBs浓度季节变化特征表明,不同季节采样点PCBs来源不同,除历史使用外,采暖季节可能主要来自机动车排放和化石燃料的燃烧,而非采暖季节主要来自机动车排放。粒径分布表现为PCBs倾向于富集在PM2.5中,占PM10总浓度的61%~87%(平均值为72%)。PM10 and PM2.5 samples were collected at one of the major traffic crossing in the North Fourth Ring area in Beijing to investigate the concentration levels,congener profiles,particle-size distribution characters and seasonal variation trends of PCBs.The results showed that the concentration and WHO-TEQ of 19 PCBs ranged 1.05-13.83 pg/m^3(average 6.66 pg/m^3)and 1.24-15.18 fg/m^3(average 6.84 fg/m^3)in PM10,0.80-8.51 pg/m^3(average 4.32 pg/m^3)and 0.88-13.40 fg/m^3(average 5.90 fg/m^3)in PM2.5,respectively.The distribution pattern of the congeners of PCBs and the dominant contributors to PCB concentrations and TEQ in PM10 and PM2.5 were similar,the most abundant PCBs were PCB-28 and PCB-209,while,PCB126 was the maximum contributor to TEQ.The seasonal variation of PCBs concentrations was distinct,which showed obviously higher values in winter and spring as compared with summer and autumn.Seasonal variation of PCB concentrations indicated that the emission sources may be different.Except using in history,fossil fuel combustion and automobiles may be the main dioxins emission sources during the heating period,whereas,in non-heating period,the automobiles alone are the main emission sources.A significantly particle size distribution profiles were observed that PCBs primarily associated with particles PM2.5,contributing 61%-87%(average 72%)to the total concentrations in PM10.

关 键 词：大气颗粒物 交通路口 多氯联苯 季节变化 粒径分布 

分 类 号：X823[环境科学与工程—环境工程]