北京市交通路口大气颗粒物污染特征研究(Ⅲ)——大气颗粒物中多环芳烃污染特征

Pollution Property of Particulates in the Air at the Traffic Crossing in Beijing Part Ⅲ: Pollution Property of PAHs in the Particulates in the Air

研究了北京市典型交通路口大气颗粒物中多环芳烃的污染特征及影响因素。于2000年6月在北京市主要交通路口之一的崇文门路口采集大气中TSP,PM10和PM2 5样品,并进行样品中ρ(PAHs)的分析及机动车流量调查。研究结果表明:机动车排放是交通路口大气颗粒物中PAHs的首要来源;多环芳烃在粒径较小的粒子中比例较高;白天ρ(PAHs)随机动车流量的增加而增加,夜晚ρ(PAHs)高于白天;污染源识别表明,交通路口大气颗粒物中的多环芳烃除主要来源于机动车尾气排放外,还有一部分来源于道路扬尘。

Pollution property of PAHs in the particulates in the air and its affecting factors at the traffic crossing in Beijing were studied. Samples of TSP, PM_(10( and PM_(2.5( were collected at one of the major traffic crossings, Chongwenmen crossing, in June 2000. The mass concentration of PAHs in the particulates was measured. The flux of vehicles through the crossing during sampling was also investigated. Results showed that vehicle emission was the major source of PAHs in the particulates at the traffic crossing. PAHs were mainly in the particulates of small size. The mass concentration of PAHs went up with the increase of the flux of vehicles in the daytime. At night the mass concentration of PAHs was higher than that in the daytime. The identification of pollution sources showed that a small part of PAHs in the particulates at the traffic crossing came from the raised dust in the street beside the emission of the vehicles.