Based on the PM2.5 sample data collected from Shangdianzi regional atmospheric background station in 2015,the variation characteristics of PM2.5 mass concentration and its chemical components were analyzed,and its sources were traced by mass closure,backward trajectory,and potential source contribution methods.The results show that the annual average PM2.5 mass concentration at Shangdianzi station in 2015 was 44.9 μg·m-3,with aver-age concentrations of 58.1 µg·m-3 in spring,30.9 μg·m-3 in summer,39.7 μg·m-3 in autumn,and 51.3 μg·m3 in winter.Compared with 2009 to 2010,they decreased by 33％,56％,46％,and 9％respectively.The annual aver-age mass concentrations of SO4-,NO3-and NH4+are 8.5±9.2,6.4±8.3,and 3.9±4.7 μg·m-3,respectively.The average annual concentrations of organic carbon and elemental carbon are 8.9±6.3 μg·m-3 and 1.6± 1.2 μg·m-3,respectively.The daily average concentration ratio of NO3-to SO42-is 0.82,which is higher than the observed results in 2004,2012 and 2013.The main components of PM2.5 are soil,organic matter,sulfates,and ni-trates,accounting for 34％,23％,22％,and 15％,respectively.Compared with 2004,the proportion of sulfate in PM2.5 at Shangdianzi station has decreased,while the proportion of soil components has increased.The PM2.5 at Shangdianzi station primarily originates from the southern,northwestern,and northern of the station,and regional transmission from Hebei and Shandong provinces has a great impact on the high concentration of PM2.5 in Shangdi-anzi Station.
万方数据
