济南市秋末冬初大气颗粒物和气体污染物污染水平及来源

2009年11月23日─12月7日在济南市区对PM2.5、BC(黑碳)和污染物(SO2、NOx、NO、NO2和CO)进行实时监测与分析.观测期间ρ(PM2.5)、φ(SO2)和φ(NOx)分别为171μg/m3、54.3×10-9和107×10-9.其中,φ(SO2)与GB 3095─1996《环境空气质量标准》日标准值相当,φ(NOx)是标准的2.2倍,ρ(PM2.5)是美国环境空气质量标准(35μg/m3)的4.89倍.污染事件期间ρ(PM2.5)、φ(SO2)和φ(NOx)分别达到222μg/m3、74.4×10-9和158×10-9,是非污染期间的1.78、1.67和1.77倍.观测期间SO2主要来源于燃煤排放.在11月25─26日的污染事件中,NOx、BC和PM2.5主要来源于机动车尾气排放,除局地源外,东北风经过济南东北部工业区时也将污染物传输到采样点;而在12月1─2日的污染事件中,以静风为主,污染物积聚,NOx和BC主要来源于机动车尾气排放,PM2.5除了一次污染物,很可能包含一定比例的二次污染物.在非污染事件中,NOx和BC主要来源于机动车尾气排放,部分NOx很可能来源于燃煤排放,而PM2.5主要来源于一次源排放.

Particle and Gaseous Pollutant Levels and Sources in the Late Fall and Early Winter in Ji'nan City

Comprehensive monitoring and analysis of PM2.5,black carbon(BC) and gaseous pollutants(SO2,NOx,NO,NO2 and CO) were carried out in Ji’nan City,Shandong Province,from 23 November to 7 December 2009.During the monitoring period,the average values of ρ(PM2.5),φ(SO2) and φ(NOx) were 171 μg/m3,54.3×10-9 and 107×10-9,respectively.φ(SO2) was comparable to the daily value of China’s National Air Quality Standard,while φ(NOx) was 2.2 times higher than its corresponding standard.ρ(PM2.5) was 4.89 times higher than the US National Ambient Air Quality Standard(35 μg/m3).ρ(PM2.5),φ(SO2) and φ(NOx) during pollution episodes were 222 μg/m3,74.4×10-9 and 158×10-9,respectively,which were 1.78,1.67 and 1.77 times higher than those during non-pollution days.On both pollution and non-pollution days,SO2 was mainly from coal-fired emissions.However,during the pollution episode from November 25th to 26th,NOx,BC and PM2.5 were primarily from vehicle exhaust emissions.During the episodes,pollutants in the sampling site were from local sources as well as transported in by wind from the industrial district in the northeast part of Ji’nan City.During the pollution incident from December 1st to 2nd,winds were mostly calm,and the pollutants accumulated.The main sources of NOx and BC were vehicle exhaust emissions.Besides primary sources,part of the PM2.5 was probably from secondary pollution.On the non-pollution days,NOx and BC were mainly from vehicle exhaust emissions,part of NOx was possibly from coal-fired emissions,and PM2.5 was mainly originated from primary sources.