机动车道路扬尘与PM直接排放的测算与分析

Calculation and Analysis of Particulate Matters(PM)from Vehicle Road Dust and Direct Vehicle Exhaust

目前对交通扬尘总量的量化及其与机动车尾气排放量的直接关系缺乏论述,且对交通行业排放率的认识存在结构性偏差。以北京市六环内道路网络为研究实例,利用中国机动车排放模型,结合交通运行参数,测算了机动车直接排放PM10的总量并对其来源进行分析。同时,参照AP-42排放因子模型,利用各类型道路的机动车行驶里程、平均车重等统计数据,测算得到交通扬尘PM2.5和PM10总量。研究结果表明:机动车直接排放PM10总量中,重型车排放占98.3%,国III排放标准机动车占85.4%,快速路占41.3%;交通扬尘PM10与机动车直接排放PM10总量基本相等,而交通扬尘PM2.5约为机动车直接排放PM2.5总量的1/5。若将道路扬尘计入交通源排放PM2.5的统计口径中,将显著增大交通源排放对PM2.5的贡献率。这一研究有助于科学认识北京市PM2.5的来源并为PM污染防治提供决策基础。

Given the fact that there have been few studies of the quantification of the road dust and its comparative relationship with vehicle exhaust emissions, and bias exists in the understanding of transportation sector emissions, this research first estimated the total PM10 based on the direct vehicle exhaust by utilizing the China Vehicle Emission Model （CVEM） and traffic operational parameters of the road network collected within the 6th Ring Road of Beijing, and ana- lyzed the exhaust sources. Then, the total PM10 and PMz. s road dusts were calculated by using the AP-42 emission model with a combination with vehicle kilometers travelled （VKTs） for each road class. The research results show that heavy duty vehicles account for 98.3% of the total PM10 from the direct vehicle exhaust within the 6th Ring Road of Beijing, motor vehicles of euro III emission standard account for 85.4%, and expressways represent 41.3%. Meanwhile, the road dust PM10 is approximately equal to the PM10 from the vehicle exhaust. However, the road dust PM2.5 is about 20% of that from the direct vehicle exhaust. If the road dust is considered in PM2.5 as a traffic emission source, it will significantly increase the contributions of traffic emission sources to PM2. 5 This research will help further understand the sources of PM pollutions, and provide decision-making basis for the PM pollution prevention.