Pollution characteristics and potential sources of nitrous acid (HONO) in early autumn 2018 of Beijing

Chenhui Jia; Shengrui Tong; Wenqian Zhang; Xinran Zhang; Weiran Li; Zhen Wang; Lili Wang; Zirui Liu; Bo Hu; Pusheng Zhao; Maofa Ge

doi:10.1016/j.scitotenv.2020.139317

Pollution characteristics and potential sources of nitrous acid (HONO) in early autumn 2018 of Beijing

Sci Total Environ. 2020 Sep 15:735:139317. doi: 10.1016/j.scitotenv.2020.139317. Epub 2020 May 11.

Authors

Chenhui Jia¹, Shengrui Tong², Wenqian Zhang³, Xinran Zhang³, Weiran Li³, Zhen Wang³, Lili Wang⁴, Zirui Liu⁴, Bo Hu⁴, Pusheng Zhao⁵, Maofa Ge⁶

Affiliations

¹ State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China.
² State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China. Electronic address: tongsr@iccas.ac.cn.
³ State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China.
⁴ State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences, Beijing 100029, PR China.
⁵ Institute of Urban Meteorology, China Meteorological Administration, Beijing, 100089, PR China.
⁶ State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, PR China.

PMID: 32473443
DOI: 10.1016/j.scitotenv.2020.139317

Abstract

Nitrous Acid (HONO) is an important precursor of hydroxyl radical (OH) and has significant impacts on the formation of Ozone (O₃) and Secondary Organic Aerosol (SOA). The atmospheric concentrations of HONO were measured during early autumn in downtown, Beijing (China). This study investigated HONO pollution characteristics and potential sources during day and night. The maximum hourly HONO levels reached 5.16 ppb, with 1.23 ppb on average. HONO concentration exhibited typical diurnal variation characteristics, with maximum at nighttime and minimum at daytime. The potential sources mainly included vehicle emission, heterogeneous reaction of NO₂ on aerosol surfaces (Photo-enhanced at the daytime) and photolysis of particulate nitrate (NO₃^-) in Beijing. Vehicle emission was an important HONO source, particular at the morning rush period and lower HONO concentration. The simulated results highlighted that the main contribution of HONO was NO₂ heterogeneous reaction on aerosol surfaces. The photolysis of particulate NO₃^- was also an important daytime HONO source, particularly in the pollution period. The main loss routine was the photolysis of HONO and dry deposition at day and night, respectively.

Keywords: Aerosol surfaces; Beijing; Nitrous acid; Particulate nitrate; Source.