上海市浦东城区冬季颗粒物数浓度及其谱分布特征

Size Distribution Properties of Atmospheric Aerosol Particles During Winter in the Downtown of Pudong,Shanghai

采用APS-3321空气动力学粒径谱仪对上海市浦东城区2012年12月至2013年2月0.5～20μm大气颗粒物浓度及其谱分布进行了实时监测。结果发现,上海市浦东城区冬季大气颗粒物数浓度为360个/cm3,其中0.5～1.0μm颗粒物数为345个/cm3,占总颗粒物的95.7%;1.0～2.5μm颗粒物数为15个/cm3,占颗粒物总数的4.1%;2.5～20.0μm颗粒物数为0.6个/cm3,占颗粒物总数的0.2%。当空气质量为AQI≤50、50200时,颗粒物数浓度分别为77.5、243.2、522.6、868.5个/m3。随着空气污染的加重,小于PM2.5颗粒物数浓度增加显著且对总的颗粒物数浓度的贡献也有所增加,且AQI〉200时,PM2.5中1.0～2.5μm颗粒物数浓度贡献增幅最大;此外,不同空气质量条件下,颗粒物数浓度的日变化存在一定差异,这对于空气污染防治具有重要意义。

Analyses of diurnal patterns of particle number concentration and size distribution （0.5-20 μm） in the downtown of Pudong, Shanghai have been performed in this study from December,2012 to Febrary,2013. Results show that particle number eoncentration was 360 cm 3 , ineluding 0.5-1.0 p.m were 345 em -3 （95.7% of total number concentration） , 1.0-2.5 p.m were 15 cm -3 （4. 1% of total number concentratlon） , 2.5-20 μm were 0.6 cm 3 （0.2% of total number concentration）. When AQI （Air Quality Index） were ≤ 50 - 50-100,100-200 and 〉 200, particle number concentration were respectively 77.5,243.2, 522.6 and 868.5 m-3o Along with AQI increasing, fine particle number concentration was dramatically increased, and contribution percentage was also increased, and contribution of number concentration of 1.0-2.5 μm increased most among all AQ1 levels, when AQI 〉 200. In addition, daily variation of particle number concentration also revealed different trends for different AOI levels. These results were very important for the prevention and control of air pollution.