[A-AS05] [EE] Contributions of local and long-range transport to air pollutants in mega-cities

[AAS05-P14] Emissions of fine particulate nitrated phenols from the burning of five common types of biomass

*Xinfeng Wang¹, Rongrong Gu¹, Liwei Wang¹, Wenxue Xu¹, Yating Zhang¹, Bing Chen¹, Weijun Li¹, Likun Xue¹, Jianmin Chen¹, Wenxing Wang¹ (1.Shandong University)

Keywords:Nitrated phenols, emission, biomass burning, fine particulate matter, smoke

Nitrated phenols are among the major constituents of brown carbon and affect both climates and ecosystems. However, emissions from biomass burning, which comprise one of the most important primary sources of atmospheric nitrated phenols, are not well understood. In this study, the concentrations and proportions of 10 nitrated phenols, including nitrophenols, nitrocatechols, nitrosalicylic acids, and dinitrophenol, in fine particles from biomass smoke were determined under three different burning conditions (flaming, weakly flaming, and smoldering) with five common types of biomass (leaves, branches, corncob, corn stalk, and wheat straw). The total abundances of fine nitrated phenols produced by biomass burning ranged from 2.02 to 99.52 μg m^-3. The compositions of nitrated phenols varied with biomass types and burning conditions. 4-nitrocatechol and methyl nitrocatechols were generally most abundant, accounting for up to 88–95% of total nitrated phenols in flaming burning condition. The emission ratios of nitrated phenols to PM_2.5 increased with the completeness of combustion and ranged from 7 to 45 ng mg^-1 and from 239 to 1081 ng mg^-1 for smoldering and flaming burning, respectively. The ratios of fine nitrated phenols to organic matter in biomass burning aerosols were comparable to or lower than those in ambient aerosols affected by biomass burning, indicating that secondary formation contributed significantly to ambient levels of fine nitrated phenols. The emission factors of fine nitrated phenols from flaming biomass burning were approximately 0.75–11.07 mg kg^-1. According to calculations based on corn and wheat production in 31 Chinese provinces in 2013, the total estimated emission of fine nitrated phenols from the burning of corncobs, corn stalks, and wheat straw was 670 t. This work highlights the apparent emission of methyl nitrocatechols from biomass burning and provides basic data for modeling studies.