| 摘 要： | Ozone(O3) and secondary organic aerosol(SOA) are considered to be the most serious secondary air pollutants of concern in most metropolitan areas,as well as for Beijing.In this study,O3 and SOA for-mation potential of α-pinene,the most abundant biogenic VOCs,is investigated at Tsinghua Indoor Chamber Facility.The experiments were conducted under atmospheric relevant HCs/NOx ratios in both presence and absence of ammonia sulfate seed aerosol.A Scanning Mobility Particle Sizer system(3936,TSI) and a Condensation Particle Counter(3010,TSI) were used to study the SOA formation and a gas chromatograph(GC) equipped with a DB-5 column and a flame ionization detector(FID) was used to measure α-pinene simultaneously.The results show that the presence of ammonia sulfate seed aerosol did not change the formation trend of O3,but significantly contribute to SOA formation.A strong linear relationship(r2 = 0.90) between SOA yield enhancement(△Y*) and surface concentration of seed aerosol(PMi,s)has been found,denoting that the PMi,s is the control factor for SOA yield en-hancement.And the possible reason for the enhancement is acid-catalyzed heterogeneous reactions.
|
