Molecular characterization of firework-related urban aerosols using Fourier transform ion cyclotron resonance mass spectrometry

Qiaorong Xie,Haijie Tong,Shuang Chen,Pingqing Fu,Wanyu Zhao,Yele Sun,Yafang Cheng,Kimitaka Kawamura,Hang Su,Yisheng Xu,Guibin Jiang,Sihui Su,Siyao Yue,Zifa Wang,Cong-Qiang Liu,Dong Cao,Lujie Ren,Jing Chen

doi:10.5194/acp-20-6803-2020

Abstract

Abstract. Firework (FW) emission has strong impacts on air quality and public health. However, little is known about the molecular composition of FW-related airborne particulate matter (PM), especially the organic fraction. Here we describe the detailed molecular composition of Beijing PM collected before, during, and after a FW event in the evening of New Year's Eve in 2012. Subgroups of CHO, CHON, and CHOS were characterized using ultrahigh-resolution Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry. These subgroups comprise a substantial fraction of aromatic-like compounds with low O∕C ratio and high degrees of unsaturation, some of which plausibly contributed to the formation of brown carbon in Beijing PM. Moreover, we found that the number concentration of sulfur-containing compounds, especially the organosulfates, increased dramatically during the FW event, whereas the number concentration of CHO and CHON doubled after the event, which was associated with multiple atmospheric aging processes including the multiphase redox chemistry driven by NOx, O3, and •OH. These findings highlight that FW emissions can lead to a sharp increase in high-molecular-weight compounds, particularly aromatic-like substances in urban particulate matter, which may affect the light absorption properties and adverse health effects of atmospheric aerosols.

Highlights

The widespread haze pollution in China has aroused much attention due to its strong impacts on air quality, human health, and climate change (Ramanathan et al, 2001; Pöschl, 2005; Lelieveld et al, 2015; Thomason et al, 2018; Kaufman et al, 2002)
We found that the number concentration of sulfur-containing compounds, especially the organosulfates, increased dramatically during the FW event, whereas the number concentration of CHO and CHON doubled after the event, which was associated with multiple atmospheric aging processes including the multiphase redox chemistry driven by NOx, O3, and OH
We investigated HMW organic compounds in urban aerosols collected during the Chinese New Year in Beijing, including the periods of before FW, during FW, and after FW, by the usage of electrospray ionization (ESI) FT-ICRMS

Summary

Introduction

The widespread haze pollution in China has aroused much attention due to its strong impacts on air quality, human health, and climate change (Ramanathan et al, 2001; Pöschl, 2005; Lelieveld et al, 2015; Thomason et al, 2018; Kaufman et al, 2002). The levels of haze pollution are strongly dependent on the source of haze particles, e.g., industry, coal combustion, vehicle emissions, cooking, and biomass burning (Sun et al, 2013; Zheng et al, 2005). Among different haze particle sources the firework (FW) emission can be expected to play an important role in urban air quality during festivals (Feng et al, 2012; Jing et al, 2014; Jiang et al, 2015; Tian et al, 2014). The chemical composition of FW-related aerosols, especially the organic fraction, is not well characterized. Q. Xie et al.: Molecular characterization of firework-related urban aerosols

Methods

Results

Conclusion