Secondary aerosol formation in incense burning particles by O3 and OH oxidation via single particle mixing state analysis

Zhancong Liang; Liyuan Zhou; Xinyue Li; Rosemarie Ann Infante Cuevas; Rongzhi Tang; Mei Li; Chunlei Cheng; Yangxi Chu; Patrick K H Lee; Alvin C K Lai; Chak K Chan

doi:10.1016/j.scitotenv.2023.164942

Secondary aerosol formation in incense burning particles by O₃ and OH oxidation via single particle mixing state analysis

Sci Total Environ. 2023 Oct 10:894:164942. doi: 10.1016/j.scitotenv.2023.164942. Epub 2023 Jun 16.

Authors

Affiliations

¹ School of Energy and Environment, City University of Hong Kong, Hong Kong, China; City University of Hong Kong Shenzhen Research Institute, Shenzhen, China.
² School of Energy and Environment, City University of Hong Kong, Hong Kong, China.
³ Institute of Mass Spectrometry and Atmospheric Environment, Guangdong Provincial Engineering Research Center for On-line Source Apportionment System of Air Pollution, Jinan University, Guangzhou 510632, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 510632, China.
⁴ State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
⁵ School of Energy and Environment, City University of Hong Kong, Hong Kong, China; City University of Hong Kong Shenzhen Research Institute, Shenzhen, China; Division of Physical Science and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia. Electronic address: chak.chan@kaust.edu.sa.

PMID: 37329918
DOI: 10.1016/j.scitotenv.2023.164942

Abstract

Incense burning is a common religious activity that emits abundant gaseous and particulate pollutants into the atmosphere. During their atmospheric lifetime, these gases and particles are subjected to oxidation, leading to the formation of secondary pollutants. We examined the oxidation of incense burning plumes under O₃ exposure and dark condition using an oxidation flow reactor connected to a single particle aerosol mass spectrometer (SPAMS). Nitrate formation was observed in incense burning particles, mainly attributable to the ozonolysis of nitrogen-containing organic compounds. With UV on, nitrate formation was significantly enhanced, likely due to HNO₃/HNO₂/NOx uptake triggered by OH chemistry, which is more effective than ozone oxidation. The extent of nitrate formation is insensitive to O₃ and OH exposure, possibly due to the diffusion limitation on interfacial uptake. The O₃-UV-aged particles are more oxygenated and functionalized than O₃-Dark-aged particles. Oxalate and malonate, two typical secondary organic aerosol (SOA) components, were found in O₃-UV-aged particles. Our work reveals that nitrate, accompanied by SOA, can rapidly form in incense-burning particles upon photochemical oxidation in the atmosphere, which could deepen our understanding of air pollution caused by religious activities.

Keywords: Biomass burning; Incense burning particles; Nitrate; Ozone; Photochemical oxidation; SOA.