AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
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Secondary Organic Aerosol (SOA) and Ozone Formation from Low NOx Photo-oxidation of Select Intermediate-Volatility Organic Compounds (IVOCs) and Consumer Products Containing Them in the Presence of a Surrogate Mixture
WEIHUA LI, Lijie Li, Chia-Li Chen, Mary Kacarab, Peng Weihan, David R. Cocker III, University of California, Riverside
Abstract Number: 390 Working Group: Aerosol Chemistry
Abstract Organic compounds with vapor pressure216 °C are distinguished as low vapor pressure-volatile organic compounds (LVP-VOCs) and are provided ozone exemptions by regulating agencies due to low evaporation rates. LVP-VOCs studied in this work, however, fall in the IVOC range. Therefore, we evaluated atmospheric availability of select IVOCs and found that these IVOCs have great potential to enter the atmosphere and contribute to SOA and ozone formation at ambient conditions after extended period of time. We also studied SOA and ozone formation from the select individual IVOCs and IVOC-containing generic consumer products under low-NOx conditions using H2O2 as the OH radical source as needed in the presence of a surrogate mixture in the advanced environmental smog chamber facility housed at the College of Engineering, Center for Environmental Research and Technology at UC Riverside. Our study showed that half of the select IVOCs did not form noticeable SOA, which contradicts our expectation that the select IVOCs would form significant SOA due to their high boiling points and low vapor pressures. Only three select IVOCs have yields greater than 0.1 without added H2O2 and only n-Heptadecane have very high yields relative to common VOC precursors. Although ozone formations from several individual IVOCs were suppressed, because of different sensitivities to effects on radical levels, NOx concentrations, and other factors, the effects on ozone in the experiments is not exactly the same as their effects on ozone in the atmosphere. The addition of lab created generic consumer products had a weak influence on ozone formation from the surrogate mixture but strongly affected SOA formation. The overall SOA and ozone formation of the generic consumer product could not be explained solely by the results of the pure IVOC experiments.