Characteristics of Carbonaceous Aerosols in Yangtze River Delta Region, China

摘要

Mass concentrations of organic carbon (OC) and elemental carbon (EC) in both PM2.5 and size-resolved aerosols collected in five cities (Jiading District of Shanghai, Hangzhou, Nanjing, Zhoushan and Taicang) of Yangtze River Delta Region (YRDR), China, in the period of April 25th to May 19th and October 19th to November 2nd, 2009, with size range of <0.49 μm, 0.49- 0.95 μm, 0.95-1.5 μm, 1.5-3.0 μm, 3.0-7.2 μm, >7.2 μm were determined. The secondary organic carbon (SOC) was also estimated based on the EC tracer method. Average mass concentrations of OC and EC in the PM2.5 were 15.9 and 4.0 μg·m-3 while those in the total size-resolved aerosols were 19.2 and 3.4μg·m-3, respectively. Mass concentrations of OC and EC accounted for 18.7% and 4.8% of the PM2.5, as well as they accounted for 12.5% and 2.2% of the total size-resolved aerosols, respectively. Concentrations of OC and EC in the size-resolved aerosols showed a typical bio-modal with peaks in size ranges of < 0.49 μm and >3.0 μm respectively. Mass concentration of SOC in the PM2.5 was 6.6 μg·m-3, accounting for 42% of OC in the PM2.5 . Size distribution of SOC in the size-resolved aerosols collected in Jiading district of Shanghai indicated the abundance of SOC in both fine and coarse aerosols.