Gaseous nitrous acid (HONO) is a crucial precursor of the hydroxyl (OH) radical, which is a "detergent" in the atmosphere. Nowadays, HONO formation mechanisms at polluted urban areas are controversial, which restricts the understanding of atmospheric oxidative capacity and radical cycling. Herein, multiday vertical observation of HONO and NO was simultaneously performed at three heights at the urban area of Beijing for the first time. The vertical distribution of HONO was often unexpected, and it had the highest HONO concentration at 120 m, followed by those at 8 and 240 m. 0D box model simulations suggest that ground and aerosol surfaces might play similar roles in NO conversion at 8 m during the whole measurement. NO conversion on aerosol surfaces was the most important HONO source aloft during haze days. At daytime, a strong missing HONO source unexpectedly existed in the urban aloft, and it was relevant to solar radiation and consumed OH.
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http://dx.doi.org/10.1021/acs.est.0c02146 | DOI Listing |
Environ Sci Technol
January 2025
Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), CNRS-Université Orléans-CNES, Orléans Cedex 2 45071, France.
The source of nitrous acid (HONO) and its importance in island or marine environments are poorly understood. Herein, based on comprehensive field measurements at a hilltop on Corsica Island, we find an inverse diel variation of HONO with higher concentrations during daytime. Night-time HONO budget analysis indicates significant HONO formation during air mass transport along the hillside.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Department of Chemistry, Malaviya National Institute of Technology Jaipur, Jaipur, 302017, India.
The present work employs the CCSD(T)/CBS//M06-2X/aug-cc-pVTZ level of theory to investigate the effect of a water monomer (WM) and dimer (WD) on the oxidation of nitrous acid (HONO) by the Criegee intermediate (CHOO). The present work suggests that similar to an uncatalyzed path, a water catalyzed reaction can also proceed two paths, , the oxygen atom transfer (OAT) and the hydrogen atom transfer (HAT) path. In addition, here also, the HAT path dominates over the OAT path.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
NO is a significant primary atmospheric pollutant that plays a key role in atmospheric chemistry. It serves as a crucial precursor to photochemical smog, acid rain, and secondary particulate matter and is instrumental in determining the atmospheric oxidation capacity. In this review, we focus on the heterogeneous chemistry of NO, which has been demonstrated to significantly influence the sources and sinks of various nitrogen-containing species through field measurements and model simulations.
View Article and Find Full Text PDFEnviron Pollut
January 2025
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China. Electronic address:
As a vital precursor of hydroxyl radicals (OH), atmospheric nitrous acid (HONO) plays a significant role in tropospheric chemistry and the production of secondary pollutants. However, knowledge of its sources remains insufficient. To comprehensively investigate the HONO chemistry in polluted cities and alleviate O pollution, based on a comprehensive HONO-related field campaign in Zibo City, on the North China Plain, the parameterized formulas of additional HONO sources were validated in a box model (based on the default MCMv3.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong SAR 999077, China.
An adequate understanding of the NO interacting chemistry is a prerequisite for a smoother transition to carbon-lean and carbon-free fuels such as ammonia and hydrogen. In this regard, this study presents a comprehensive study on the H atom abstraction by NO from C to C alkynes, dienes, and trienes forming 3 HNO isomers (i.e.
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