[Estimate of the formation potential of secondary organic aerosol in Beijing summertime].
Fractional aerosol coefficients (FAC) are used in conjunction with measurements of volatile organic compounds (VOC) during ozone episodes to estimate the formation potential of secondary organic aerosols (SOA) in the summertime of Beijing. The estimation is based on the actual atmospheric conditions of Beijing, and benzene and isoprene are considered as the precursors of SOA. The results show that 31 out of 70 measured VOC species are SOA precursors, and the total potential SOA formation is predicted to be 8.48 microg/m3, which accounts for 30% of fine organic particle matter. Toluene, xylene, pinene, ethylbenzene and n-undecane are the 5 largest contributors to SOA production and account for 20%, 22%, 14%, 9% and 4% of total SOA production, respectively. The anthropogenic aromatic compounds, which yield 76% of the calculated SOA, are the major source of SOA. The biogenic alkenes, alkanes and carbonyls produce 16%, 7% and 1% of SOA formation, respectively. The major components of produced SOA are expected to be aromatic compounds, aliphatic acids, carbonyls and aliphatic nitrates, which contribute to 72%, 14%, 11% and 3% of SOA mass, respectively. The SOA precursors have relatively low atmospheric concentrations and low ozone formation potential. Hence, SOA formation potential of VOC species, in addition to their atmospheric concentrations and ozone formation potential, should be considered in policy making process of VOCs control.
Lü
Zi-Feng
ZF
Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China. lvzifeng@tsinghua.org.cn
Hao
Ji-Ming
JM
Duan
Jing-Chun
JC
Li
Jun-Hua
JH
D000336:Aerosols / Q000032:analysis*; D000393:Air Pollutants / Q000032:analysis*; D002244:Carbon / Q000032:analysis; D002681:China; D002947:Cities; D004784:Environmental Monitoring; D006838:Hydrocarbons / Q000032:analysis; D009930:Organic Chemicals / Q000032:analysis*; D010126:Ozone / Q000032:analysis* / Q000737:chemistry; D010316:Particle Size; D012621:Seasons
D000336:Aerosols; D000393:Air Pollutants; D006838:Hydrocarbons; D009930:Organic Chemicals; D010126:Ozone; D002244:Carbon