AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Indoor Secondary Organic Aerosol Formation due to α-Terpineol Ozonolysis
Yanan Yang, MICHAEL WARING, Drexel University
Abstract Number: 282 Working Group: Indoor Aerosols
Abstract Secondary organic aerosol (SOA) owing to reactive organic gas (ROG) ozonolysis can be an important indoor particle source in some settings. However, the SOA formation potential due to ozonolysis of α-terpineol, which is emitted by consumer product usage and reacts strongly with ozone indoors, has not been systematically quantified. Therefore, we conducted 21 experiments to investigate the SOA formation initiated by α-terpineol ozonolysis for three typical conditions of the air exchange rate (AER), which is the frequency with which indoor is replaced by outdoor air. Initial α-terpineol concentrations, ranging from 6.39 to 226 ppb, were combined with high ozone (~25 ppm) to ensure rapid and complete oxidation. No reactants were replenished so SOA peaked quickly and then decreased due to AER and surface losses, and loss-corrected peak SOA ranged from 2.03 to 281 µg/m3 at unit density. SOA mass formation was parameterized with the aerosol mass fraction (AMF), a.k.a. the SOA yield, which is the ratio of SOA mass formed to ROG mass converted. The AMFs ranged from 0.05 to 0.23 and were similar in magnitude to AMFs due to α-pinene ozonolysis. The α-terpineol AMFs strongly and positively correlated with larger SOA peak mass concentrations, whereas they weakly and negatively correlated with higher AERs. One-product, two-product, and volatility basis set (VBS) models were fit to the experimental AMFs at each AER for future modeling, and the efficacy of those three formulations at reproducing experimental AMFs was evaluated. Predictive cases demonstrated that α-terpineol ozonolysis can meaningfully form SOA in indoor air when certain consumer products are used indoors.