Abundant nitrogen oxide and weakly acidic environment synergistically promote daytime particulate nitrate pollution

Yuting Wei; Athanasios Nenes; Jie Gao; Weiqing Liang; Danni Liang; Guoliang Shi; Yinchang Feng; Armistead G Russell

doi:10.1016/j.jhazmat.2023.131655

Abundant nitrogen oxide and weakly acidic environment synergistically promote daytime particulate nitrate pollution

J Hazard Mater. 2023 Aug 15:456:131655. doi: 10.1016/j.jhazmat.2023.131655. Epub 2023 May 16.

Authors

Yuting Wei¹, Athanasios Nenes², Jie Gao¹, Weiqing Liang¹, Danni Liang¹, Guoliang Shi³, Yinchang Feng¹, Armistead G Russell⁴

Affiliations

¹ State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; CMA-NKU Cooperative Laboratory for Atmospheric Environment-Health Research (CLAER), College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
² Laboratory of Atmospheric Processes and their Impacts, School of Architecture, Civil and Environmental Engineering, École Polytechnique Fédérale de Lausanne, Lausanne CH-1015, Switzerland; Center for the Study of Air Quality and Climate Change, Institute of Chemical Engineering Sciences, Foundation for Research and Technology Hellas, Patras GR-26504, Greece.
³ State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, Tianjin Key Laboratory of Urban Transport Emission Research, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China; CMA-NKU Cooperative Laboratory for Atmospheric Environment-Health Research (CLAER), College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China. Electronic address: nksgl@nankai.edu.cn.
⁴ School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.

PMID: 37216807
DOI: 10.1016/j.jhazmat.2023.131655

Abstract

Nitrate is formed through the chemical production of gas-phase nitric acid and subsequent partitioning to the aerosol phase during the daytime. Many studies in the past separated these two aspects, even though they occur simultaneously in the atmosphere. To better understand the nitrate formation mechanism and effectively mitigate its production, it is necessary to consider the synergy between these two mechanisms. For this, we analyze hourly-speciated ambient observations data, with EK&TMA (Empirical Kinetic & Thermodynamic Modeling Approach) map to comprehensively explore the factors controlling nitrate production. Results show that precursor NO₂ concentration and aerosol pH, which are related to anthropogenic activities, are the two major factors for chemical kinetics production and gas/particle thermodynamic partitioning processes respectively. Abundant NO₂ and weakly acidic environments are favorable conditions for daytime particulate nitrate pollution, thus collaborative control of coal source, vehicle source, and dust source is needed to alleviate nitrate pollution.

Keywords: Chemical kinetics; Gas phase; Nitrate production; Synergistic effect; Thermodynamics.