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Sun M, Zhou Y, Wang Y, Zheng X, Cui J, Zhang D, Zhang J, Zhang R. Seasonal discrepancies in peroxyacetyl nitrate (PAN) and its correlation with ozone and PM 2.5: Effects of regional transport from circumjacent industrial cities. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 785:147303. [PMID: 33933769 DOI: 10.1016/j.scitotenv.2021.147303] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 04/16/2021] [Accepted: 04/18/2021] [Indexed: 06/12/2023]
Abstract
Peroxyacetyl nitrate (PAN) is the most important reservoir of nitrogen oxides, with effects on atmospheric oxidation capacity and regional nitrogen distribution. The first yearlong observational study of PAN was conducted from September 2018 to August 2019 at a suburban site and an urban site in Zhengzhou, Henan Province, central China. Compared with studies over the past two decades, summer PAN pollution at the suburban site and winter PAN pollution at both sites were more significant, with annual average concentrations of 1.96 ± 1.44 and 2.01 ± 1.59 ppbv, respectively. Seasonal PAN discrepancies between the urban and suburban areas were analyzed in detail. Active PAN formation, regional transport, photochemical precursors, and PAN lifetime played key roles during seasons with elevated PAN (winter and spring). According to the results of cluster analysis and potential source contribution function analysis, during the cold months, short-distance air mass transport from the east, south, and southeast of Henan Province and southern Hebei Province increased PAN pollution in urban Zhengzhou. PAN source areas were located in circumjacent industrial cities surrounding Zhengzhou except in the northeastern direction. Based on the relationships between pollutant concentrations, wind speed, and wind direction, a strong positive correlation between PAN and PM2.5 (and O3) existed in winter due to their joint transport. A slow-moving, low-height air mass passed through surrounding industrial cities before reaching the study area, carrying both pollutants and leading to strong consistency between PAN and O3 levels. The long-term PAN characteristics described in this study will help clarify the causes of regional air pollution in inland city agglomerations. Moreover, the PAN correlations and joint transport of PAN and PM2.5 (or O3) support the use of PAN as an indicator of air pollution introduced from surrounding industrial areas.
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Affiliation(s)
- Mei Sun
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Ying Zhou
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
| | - Yifei Wang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Xiaochen Zheng
- Institute of Environmental Engineering (IfU), ETH Zürich, 8093 Zürich, Switzerland
| | - Jia'nan Cui
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Dong Zhang
- Research Institute of Environmental Science, College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Jianbo Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
| | - Ruiqin Zhang
- Research Institute of Environmental Science, College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, China
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Zhang B, Zhao X, Zhang J. Characteristics of peroxyacetyl nitrate pollution during a 2015 winter haze episode in Beijing. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 244:379-387. [PMID: 30352352 DOI: 10.1016/j.envpol.2018.10.078] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 10/16/2018] [Accepted: 10/16/2018] [Indexed: 06/08/2023]
Abstract
Peroxyacetyl nitrate (PAN) are effective indicators of photochemical pollution, and also play an important role in regional oxidant balance. Surprisingly, in recent years, PAN have also been detected under conditions that do not favor the photochemical processes. To obtain a better understanding of the mechanisms of formation of atmospheric compound pollution, this study examined the relationships between concentrations of PAN and other pollutants (e.g., ozone [O3] and PM2.5) during a winter haze episode. The observation periods were from December 31, 2015, to February 2, 2016, and from February 19, 2016, to March 4, 2016. The maximum daily concentration of PAN during haze episodes was 4-10 times higher than that during non-haze episodes. The continuous cumulative increase in PAN concentrations was the result of a combination of photochemical production during the daytime and production based on free radical chemical reactions during the nighttime. During the haze episode, the correlation between concentrations of PAN and O3 was weak, while a significant correlation was observed between PAN and PM2.5 concentrations (R2 = 0.82). This may have been due to higher concentrations of particulate matter impairing illumination, which can then inhibit the photochemical reactions that produce PAN and O3. OH radicals can replace the role of light in PAN formation, which can cause concentrations of PAN and O3 to vary independently. During the haze episode, the ratio of PAN/O3 was around 0.3, which was much higher than that during the clean period.
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Affiliation(s)
- Boya Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, PR China.
| | - Ximeng Zhao
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, PR China.
| | - Jianbo Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing, 100871, PR China.
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Zhao X, Gao T, Zhang J. Heterogeneous reaction of peroxyacetyl nitrate (PAN) on soot. CHEMOSPHERE 2017; 177:339-346. [PMID: 28319888 DOI: 10.1016/j.chemosphere.2017.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 02/28/2017] [Accepted: 03/01/2017] [Indexed: 06/06/2023]
Abstract
The interaction between photochemical oxidants and aerosol particles has been examined in previous atmospheric pollution studies. The heterogeneous reaction can affect the concentration of gases and free radicals, as well as the morphology and properties of particles. In this report, the interaction between the photochemical oxidant peroxyacetyl nitrate (PAN) and soot particles was investigated using a flow tube system. We used real-time online monitoring equipment to track changes in PAN concentrations. Substances on the soot surface were detected using ion chromatography (IC), x-ray photoelectron spectroscopy (XPS), and other surface analysis methods. At 295 K, the upper and lower limits of the initial uptake coefficients were 1.28 × 10-5 and 9.16 × 10-9, respectively. The heterogeneous reaction of PAN on soot was a first-order reaction to PAN under both dry and wet conditions. The products formed on soot included CH3COO-, HCOO-, NO2-, and NO3-. With an increase in relative humidity, the production of all species decreased and the relative amounts changed.
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Affiliation(s)
- Ximeng Zhao
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Tianyu Gao
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Jianbo Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
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Gao T, Han L, Wang B, Yang G, Xu Z, Zeng L, Zhang J. Peroxyacetyl nitrate observed in Beijing in August from 2005 to 2009. J Environ Sci (China) 2014; 26:2007-2017. [PMID: 25288544 DOI: 10.1016/j.jes.2014.08.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Revised: 01/10/2014] [Accepted: 01/28/2014] [Indexed: 06/03/2023]
Abstract
Measurements of peroxyacetyl nitrate (PAN) were made at a Beijing urban site each August from 2005 to 2009. Over this 5-year period, the average PAN concentration for August in each year increased from 3 (2005) to 11.7μg/m(3) (2007); however, it decreased rapidly in 2008 (4.1μg/m(3)). Generally, the variation over the 5 years showed a rise in the first part of the study period, followed by a decline. We considered two categories of local and regional air masses in this study, which revealed that the PAN concentration in Beijing was affected mainly by southeastern air masses. The August PAN variation was influenced predominantly by local air masses in 2005, but by 2009 regional air masses had become more important. This study showed the level and variation of PAN in the month of August in 5 consecutive years for the first time, and proved that control measures are useful in decreasing photochemical pollution; hence, these measures are probably feasible for other megacities too. Furthermore, this method of analyzing regional and local impacts might be useful for other studies as well.
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Affiliation(s)
- Tianyu Gao
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
| | - Li Han
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Bin Wang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Guang Yang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Zhenqiang Xu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Limin Zeng
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Jianbo Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
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Fischer EV, Jacob DJ, Yantosca RM, Sulprizio MP, Millet DB, Mao J, Paulot F, Singh HB, Roiger A, Ries L, Talbot R, Dzepina K, Pandey Deolal S. Atmospheric peroxyacetyl nitrate (PAN): a global budget and source attribution. ATMOSPHERIC CHEMISTRY AND PHYSICS 2014; 14:2679-2698. [PMID: 33758588 PMCID: PMC7983850 DOI: 10.5194/acp-14-2679-2014] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Peroxyacetyl nitrate (PAN) formed in the atmospheric oxidation of non-methane volatile organic compounds (NMVOCs) is the principal tropospheric reservoir for nitrogen oxide radicals (NOx = NO + NO2). PAN enables the transport and release of NOx to the remote troposphere with major implications for the global distributions of ozone and OH, the main tropospheric oxidants. Simulation of PAN is a challenge for global models because of the dependence of PAN on vertical transport as well as complex and uncertain NMVOC sources and chemistry. Here we use an improved representation of NMVOCs in a global 3-D chemical transport model (GEOS-Chem) and show that it can simulate PAN observations from aircraft campaigns worldwide. The immediate carbonyl precursors for PAN formation include acetaldehyde (44% of the global source), methylglyoxal (30 %), acetone (7 %), and a suite of other isoprene and terpene oxidation products (19 %). A diversity of NMVOC emissions is responsible for PAN formation globally including isoprene (37 %) and alkanes (14 %). Anthropogenic sources are dominant in the extratropical Northern Hemisphere outside the growing season. Open fires appear to play little role except at high northern latitudes in spring, although results are very sensitive to plume chemistry and plume rise. Lightning NOx is the dominant contributor to the observed PAN maximum in the free troposphere over the South Atlantic.
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Affiliation(s)
- E. V. Fischer
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - D. J. Jacob
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - R. M. Yantosca
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - M. P. Sulprizio
- School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - D. B. Millet
- Department of Soil, Water and Climate, University of Minnesota, St. Paul, MN, USA
| | - J. Mao
- Princeton University, GFDL, Princeton, NJ, USA
| | - F. Paulot
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - H. B. Singh
- NASA Ames Research Center, Moffett Field, CA, USA
| | - A. Roiger
- Institut für Physik der Atmosphäre, Deutsches Zentrum für Luft- und Raumfahrt (DLR), Oberpfaffenhofen, Germany
| | - L. Ries
- Department of Earth and Atmospheric Sciences, University of Houston, Houston, TX, USA
| | - R.W. Talbot
- Federal Environment Agency, GAW Global Station Zugspitze/Hohenpeissenberg, Zugspitze, Germany
| | - K. Dzepina
- Department of Chemistry, Michigan Technological University, Houghton, MI, USA
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Zhang H, Xu X, Lin W, Wang Y. Wintertime peroxyacetyl nitrate (PAN) in the megacity Beijing: role of photochemical and meteorological processes. J Environ Sci (China) 2014; 26:83-96. [PMID: 24649694 DOI: 10.1016/s1001-0742(13)60384-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Previous measurements of peroxyacetyl nitrate (PAN) in Asian megacities were scarce and mainly conducted for relative short periods in summer. Here, we present and analyze the measurements of PAN, O3, NO(x), etc., made at an urban site (CMA) in Beijing from 25 January to 22 March 2010. The hourly concentration of PAN averaged 0.70 x 10(-9) mol/mol (0.23 x 10(-9) -3.51 x 10(-9) mol/mol) and was well correlated with that of NO2 but not O3, indicating that the variations of the winter concentrations of PAN and 03 in urban Beijing are decoupled with each other. Wind conditions and transport of air masses exert very significant impacts on O3, PAN, and other species. Air masses arriving at the site originated either from the boundary layer over the highly polluted N-S-W sector or from the free troposphere over the W-N sector. The descending free-tropospheric air was rich in O3, with an average PAN/O3 ratio smaller than 0.031, while the boundary layer air over the polluted sector contained higher levels of PAN and primary pollutants, with an average PAN/O3 ratio of 0.11. These facts related with transport conditions can well explain the observed PAN-O3 decoupling. Photochemical production is important to PAN in the winter over Beijing. The concentration of the peroxyacetyl (PA) radical was estimated to be in the range of 0.0014 x 10(-12) -0.0042 x 10(-12) mol/mol. The contributions of the formation reaction and thermal decomposition to PAN's variation were calculated and found to be significant even in the colder period in air over Beijing, with the production exceeding the decomposition.
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Orlando JJ, Tyndall GS. Laboratory studies of organic peroxy radical chemistry: an overview with emphasis on recent issues of atmospheric significance. Chem Soc Rev 2012; 41:6294-317. [PMID: 22847633 DOI: 10.1039/c2cs35166h] [Citation(s) in RCA: 244] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- John J Orlando
- National Center for Atmospheric Research, Earth System Laboratory, Atmospheric Chemistry Division, Boulder, USA.
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Kunasek SA, Alexander B, Steig EJ, Hastings MG, Gleason DJ, Jarvis JC. Measurements and modeling of Δ17O of nitrate in snowpits from Summit, Greenland. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2008jd010103] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Thomas JL, Roeselová M, Dang LX, Tobias DJ. Molecular Dynamics Simulations of the Solution−Air Interface of Aqueous Sodium Nitrate. J Phys Chem A 2007; 111:3091-8. [PMID: 17402716 DOI: 10.1021/jp0683972] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Molecular dynamics simulations have been used to investigate the behavior of aqueous sodium nitrate in interfacial environments. Polarizable potentials for the water molecules and the nitrate ion in solution were employed. Calculated surface tension data at several concentrations are in good agreement with measured surface tension data. The surface potential of NaNO3 solutions at two concentrations also compare favorably with experimental measurements. Density profiles suggest that NO3- resides primarily below the surface of the solutions over a wide range of concentrations. When the nitrate anions approach the surface of the solution, they are significantly undercoordinated compared to in the bulk, and this may be important for reactions where solvent cage effects play a role such as photochemical processes. Surface water orientation is perturbed by the presence of nitrate ions, and this has implications for experimental studies that probe interfacial water orientation. Nitrate ions near the surface also have a preferred orientation that places the oxygen atoms in the plane of the interface.
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Affiliation(s)
- Jennie L Thomas
- Environmental Molecular Science Institute and Department of Chemistry, University of California, Irvine, California 92697, USA
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