American Association for Aerosol Research - Abstract Submission

AAAR 38th Annual Conference
October 5 - October 9, 2020

Virtual Conference

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Physical and Chemical Characteristics and Oxidative Potential of Rice Straw and Pine Stem Burning Particles

ILHWA SEO, Kwangyul Lee, Min-Suk Bae, Minhan Park, Shila Maskey, Arom Seo, Lucille Joanna Borlaza, Enrique Cosep, Kihong Park, Gwangju Institute of Science and Technology

     Abstract Number: 347
     Working Group: Combustion

Abstract
Agricultural burning and forest fires have been often observed in Northeast Asia. Fine particles emitted from biomass burning affect radiative balance, cloud formation, human health, and regional and local air quality. In this study, the laboratory-scale chamber was used for determining the emission factor, size distribution, hygroscopicity, chemical composition, morphology, and oxidative potential (OP) of rice straw and pine stem burning particles. Emission factor (number and mass) was higher for pine stem burning particles than rice straw burning particles possibly due to lower combustion rate and combustion efficiency. Bimodal number size distributions (ultrafine and accumulation modes) for rice straw and pine stem burning particles were observed at the initial burning. The longer duration of ultrafine mode (~40 min) was detected during the rice straw burning, which would be caused by the longer periods of initial flaming combustion conditions of the rice straw burning than pine stem burning. OC, OC/EC, K+/EC, Zn, and alkanoic acid in fine particles were higher for rice straw burning particles while EC, K+/OC, K+/Cl-, Fe, Cr, Al, Cu, PAHs, and resin acids were higher for pine stem burning particles. Levoglucosan in OC was similar for rice straw (6.1%) and pine stem (6.3%) burning particles. The resin acids were significantly detected in pine stem burning particles as a useful organic tracer for wood-burning particles. The higher hygroscopic growth factor (HGF) and cloud formation potential (κ), and the less number of agglomerated soot particles for rice straw burning particles were observed. OP activity (mass-normalized) was 7 times higher for rice straw burning particles than pine stem burning particles. It could be related to the higher fractions of OC and Zn, Ba, As, and higher solubility (HGF) for rice straw burning particles than pine stem particles.