北京夏冬季雾霾天气大气单颗粒物特征

Character of individual aerosol particles under haze days in summer and winter in Beijing,China

为了深入了解不同源排放大气颗粒物对北京市大气环境的影响,从而提出更有效的防污染源控制对策,减少污染,对2014年夏季7月和2015年冬季1月北京市采集的108个样品应用扫描电镜-能谱技术进行研究。结果表明硫钙颗粒和碳质颗粒在冬夏季雾霾天气均大量出现。夏季清洁天气下PM_（2.5）以上扬尘颗粒数量大于冬季。夏季雾霾天气下有机碳及含硫颗粒快速增加,冬季雾霾天气下由于燃煤供暖因素的存在,有机碳及含硫颗粒等特殊颗粒平均浓度较清洁天气增幅最高达145倍,PM1以下总颗粒数增长高达700%。夏季雾霾天气PM0.5～1颗粒数量较清洁天气增长1.6倍,冬季增长8倍。不同季节雾霾天气主导污染颗粒不同,应采取有针对性管控措施。

In order to better understand the impact of atmospheric particulate matter from different sources on the air quality in Beijing and to aid in the development of air pollution control plans, 108 aerosol samples were collected from Beijing during the summer of 2014 and winter of 2015 ,and the samples were analyzed with scan- ning electron microscopy-energy dispersive X-ray （SEM-EDX） technology. The results showed the calcium-sul- fate and carbonaceous particles significantly increased during hazy days. The amount of fugitive dust in the PM 〉25 fraction on clear days in summer was more than that in winter. Organic carbon and S-rich particles rapidly increased during hazy days in summer. As a result of coal burning, the average concentration of organic carbon and special particles such as S-rich particles increased up to 145 times compared with the levels on clear days, and the total number of particles in the PM 〈1 fraction increased by as much as 700%. During hazy days in the summer and winter,the number of particles in the PM0.5.1 fraction increased 1.6 and 8 times compared with the lev- els on clear days. The dominant particles in the atmospheric particulate matter varied with the different seasons.