北京某地铁站台空气颗粒物的数量浓度和质量浓度以及粒径分布和元素组成

为了解地铁站台空气颗粒物的污染状况,对北京某地铁站台空气颗粒物的数量浓度和质量浓度,以及粒径分布情况进行了1 d的实地监测,同时采集了站台内外的总悬浮颗粒物样品,研究了颗粒物元素组成特征。结果表明,监测粒径为0.0060~9.8900μm范围内,地铁站台空气中颗粒物总数量浓度与粒径为0.0060~0.0170μm的颗粒息息相关,总质量浓度主要取决于粒径为0.6120~6.6700μm的颗粒;早晚乘车高峰时段内站台空气中颗粒物的数量浓度和质量浓度都显著增大,晚高峰时段颗粒物质量浓度高于早高峰时段;监测期间,PM 2.39(粒径为0.0060~2.3900μm颗粒)和PM 9.89(粒径为0.0060~9.8900μm颗粒)平均质量浓度超过了环境空气中PM 2.5和PM 10的标准限值。站台空气颗粒物中Fe含量最高,Fe、Cu、Mn、Cr、Mo的含量显著高于站外。

Number/Mass Concentration,Particle Size Distribution and Elemental Composition of Airborne Particulate Matter at A Subway Station in Beijing

In order to understand the pollution status of airborne particulate matter(PM)at subway platform,a one-day site monitoring of PM concentration and particle size distribution is carried out at a subway platform in Beijing.Meanwhile,the total suspended particle(TSP)samples at the platform and outside the subway station are collected,and their elemental compositions are analyzed.The results show that at the subway platform,the total number concentration of PM within the monitored size range(0.0060~9.8900μm)is closely related with the number concentration of PM in the size range of 0.0060~0.0170μm,while the total mass concentration of PM is mainly dependent on the mass concentration of PM in the size range of 0.6120~6.6700μm.The concentrations of PM in the platform air increase during the morning and the evening rush hours,and the mass concentration of PM during the evening rush hours is higher than that in the morning rush hours.The average mass concentrations of PM 2.39(particles in the size range of 0.0060~2.3900μm)and PM 9.89(0.0060~9.8900μm)during the monitoring period rush hours are higher than the standard limits of PM 2.5 and PM 10 in ambient air.The concentration of Fe is the highest among the elements detected in TSP samples collected at the platform,and concentrations of Fe,Cu,Mn,Cr and Mo detected at the platform are significantly higher than those outside the station.