摘要
采用安德森撞击式分级采样器采集2008-06-01～2008-09-30不同粒径的大气颗粒物样品,并用美国沙漠所DRI(desert research institute)的Model 2001A热光碳分析仪对其中的元素碳和有机碳进行了分析.结果表明,平均有56%、55%和73%的PM、OC和EC富集于粒径<2.1μm的细粒子中.OC在<2.1μm中占25%,EC占5%,表明碳气溶胶是北京大气细粒子中的重要组分.对比发现,限车措施能够有效控制北京大气中碳质气溶胶的浓度.由OC与EC的比值可知,细粒子中的碳质气溶胶主要来源于汽车尾气排放和燃煤排放,粗粒子中的含碳物质主要来源于生物质燃烧及烹调过程.TSP中二次有机碳占总有机碳比例的平均值为74%.在PM2.1中的OC与二次水溶性离子表现出较高的相关性(R2值为0.88),而在>2.1μm的粗粒子中二者的相关性较弱(R2值为0.21).
Samples of airborne PM with different size were collected by cascade impactor（Andersen） in Beijing during the Beijing Olympics.Organic carbon（OC） and elemental carbon（EC） in particles were determined by DRI Model 2001A t carbon analyzer of USA.PM（56%）,OC（55%）and EC（73%） were associated with the fine particle below 2.1 μm.OC and EC account for 25% and 5% of particle below 2.1 μm,respectively,which indicates that carbonaceous aerosols are key components for controlling fine particles pollution in Beijing.It is found that Beijing auto measures were effective in abatement of carbonaceous aerosols.The ratios of OC/EC indicated that the main origins of carbonaceous aerosols in fine particle were automobile exhaust fumes and coal combustion and in coarse particle were biomass burning and cooking.The average percentage of estimated secondary OC（OCsec） in the total OC（OCtot） in TSP was 74%.The results of correlation analysis show that the correlation coefficient between the OC and secondary water soluble ions（SO42-,NO 3-,NH 4＋,NO 2-） were very high in PM2.1（R2 = 0.88）,while the correlation coefficient was very faint in particles greater than 2.1 μm（R2 = 0.21）.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2011年第2期313-318,共6页
Environmental Science
基金
LAPC开放课题基金项目(LAPC-KF-2008-14)
中国科学院知识创新工程重要方向项目(KZCX2-YW-Q02-03)
关键词
元素碳
有机碳
粒径分布
二次有机碳
来源
elemental carbon（EC）
organic carbon（OC）
size distribution
secondary organic carbon（SOC）
source
