The Characteristics, Potential Contribution Of Secondary Organic Aerosols And Ozone Of VOCs In The Northern Suburb Of Nanjing

The VOCs and EC, OC were sampled by GC5000 instrument and Model 2001A thermal/optical analyzer.The characteristics of VOCs and the implicit sources of organic aerosols were explored.The potential formation of O3 and SOA of VOCs and each source of VOCs were estimated by the MIR coefficient, the equivalent propylene concentration and the FAC coefficient, the OC/EC method respectively.The mixing ration of TVOCs is 45.63 ×10-9 and its concentration was highest in winter, autumn and lowest in summer.Diurnal variation of VOCs is bimodal.The meteorologic conditions had significant influence on the VOCs.OCl, OC2may be more derived from secondary sources and OC4 is more derived from primary pollution. The correlation between OC1, OC2 and large-molecular-weight VOCs are better than low-molecular-weight VOCs at higher temperatures (>14℃), radiation (>240 w·m-2) and relative humidity (>60%). An optimum temperature and radiation for SOA formation may exist for a certain chemical conditions.Alkenes were the most active component and its contribution to the OFP and the equivalent propylene concentration is the largest in autumn. The SOA obtained by the FAC were 2.26μg·m-3 and aromatics are the dominant component.The SOA in PM10 is highest in the winter,25.59μg·m-3 and lowest in summer,8.89μg·m-3 by OC/EC ratio method.SOA is mainly concentrated in the fine particle (<2.1μm).Vehicle and industrial were main sources of VOCs. The sources contain rich ethylene, propylene, isoprene and BTEX contributed largest parts of equivalent propylene concentration, OFP and SOA respectively.Vehicle and industrial were the main contributor to VOCs, SOA and O3 in spring, autumn and winter.Solvent source and plant source should not be overlooked in summer.