Single-particle volatility and implications for brown carbon absorption in Beijing, China

• Published in: The Science of the total environment Vol. 854; p. 158874
• Main Authors: Sun, Jiaxing, Li, Yan, Xu, Weiqi, Zhou, Wei, Du, Aodong, Li, Lei, Du, Xubing, Huang, Fugui, Li, Zhijie, Zhang, Zhiqiang, Wang, Zifa, Sun, Yele
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2023
• Subjects: Beijing; Brown carbon; Organic nitrogen; Single particles; Volatility; Beijing; Organic nitrogen; Single particles; Volatility; Brown carbon
• ISSN: 0048-9697; 1879-1026; 1879-1026
• DOI: 10.1016/j.scitotenv.2022.158874

Aerosol volatility has a substantial impact on gas-particle partitioning, aging process and hence brown carbon (BrC) absorption. Here we analyzed single-particle volatility in winter in Beijing using a thermodenuder coupled with a single particle aerosol mass spectrometer along with a suite of collocated measurements. Our results showed that elemental carbon, metals, organic nitrogen (ON) were the dominant low-volatility components. The ON-containing particles accounting for 50 % of the total low-volatility particles comprised mainly ON-organic carbon (ON-OC) particles which were associated with biomass burning and significantly enhanced during polluted periods with high relative humidity and nitrogen oxides (NOx) levels. By analyzing the relationship between single-particle volatility and BrC, we found that semi-volatile particles related to fossil fuel combustion contributed dominantly to the light absorption of BrC (~50 %). Comparatively, the low-volatility and semi-volatile particles related to biomass burning contributed 21–35 % and 10–15 %, respectively to the BrC light absorption. Our results demonstrated that single particles from different sources with different volatility showed different impacts on BrC absorption. Although low-volatility organic aerosol accounted only for ~16 % of the total ambient organics, they can contribute as much as ~30–40 % to BrC light absorption in winter in Beijing. [Display omitted] •Single-particle volatility in winter in Beijing was characterized.•Organic nitrogen-containing particles dominated the total low-volatility particles.•Low-volatility particles contributed ~30–50 % to the total brown carbon absorption.