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Liu Y, He G, Chu B, Ma Q, He H. Atmospheric heterogeneous reactions on soot: A review. FUNDAMENTAL RESEARCH 2023; 3:579-591. [PMID: 38933550 PMCID: PMC11197571 DOI: 10.1016/j.fmre.2022.02.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 01/26/2022] [Accepted: 02/17/2022] [Indexed: 10/18/2022] Open
Abstract
Soot particles, composed of elemental carbon and organic compounds, have attracted widespread attention in recent years due to their significant impacts on climate, the environment and human health. Soot has been found to be chemically and physically active in atmospheric aging processes, which leads to alterations in its composition, morphology, hygroscopicity and optical properties and thus changes its environmental and health effects. The heterogeneous reactions on soot also have a significant impact on the transformation of gaseous pollutants into secondary aerosols. Therefore, the interactions between soot and atmospheric substances have been widely investigated to better understand the environmental behaviors of soot. In this review, we systematically summarize the progress and developments in the heterogeneous chemistry on soot over the past 30 years. Atmospheric trace constituents such as NO2, O3, SO2, N2O5, HNO3, H2SO4, OH radical, HO2 radical, peroxyacetyl nitrate etc., are presented in detail from the aspect of their heterogeneous reactions on soot. The possible mechanisms and the effects of environmental conditions on these heterogeneous reactions are also addressed. Further, the impacts of the heterogeneous reactions of soot on the atmospheric environment are discussed, and some aspects of soot-related research which require further investigation are proposed as well.
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Affiliation(s)
- Yuan Liu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guangzhi He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Biwu Chu
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- Center for Excellence in Regional Atmospheric Environment and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qingxin Ma
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- Center for Excellence in Regional Atmospheric Environment and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hong He
- State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- Center for Excellence in Regional Atmospheric Environment and Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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2
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Li C, Wang H, Chen X, Zhai T, Ma X, Yang X, Chen S, Li X, Zeng L, Lu K. Observation and modeling of organic nitrates on a suburban site in southwest China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 859:160287. [PMID: 36410483 DOI: 10.1016/j.scitotenv.2022.160287] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/08/2022] [Accepted: 11/15/2022] [Indexed: 06/16/2023]
Abstract
Here we report the measurements of two types of organic nitrates (ONs), peroxy nitrates (PNs) and alkyl nitrates (ANs), in Chengdu, China, during summer 2019. The average concentrations of PNs and ANs were 1.3 ± 1.1 ppbv and 0.5 ± 0.3 ppbv during the day, with peaks of 7.7 ppbv and 1.9 ppbv, respectively, which were in the middle and upper end of the reported levels in China. Much higher PNs and ANs concentrations were found during the photochemical pollution period than during the clean period. Box model simulation was capable of reproducing PNs during photochemical pollution episodes but showed overestimation in other periods, which was likely caused by the simplification of PNs sinks. The OH oxidation of aldehydes and ketones was the most important source of the PNs precursors, PAs (peroxyacyl radicals), except for the thermal decomposition of PNs, which was further confirmed by the relative incremental reactivity (RIR) analysis. The model basically reproduced the observed ANs by the refinement of related mechanisms, with isoprene contributing to its formation by 29.2 %. The observed PNs and total oxidants (Ox = NO2 + O3) showed a good positive correlation, with a ratio of PNs to Ox of 0.079, indicating a strong suppression of PNs chemistry to ozone formation. The model quantified the suppression of PNs chemistry on the peak ozone production rate by 21.3 % on average and inhibited ozone formation up to 20 ppbv in total. The RIR analysis suggests that the production of both O3 and ANs was in the VOC-limited regime and highlights the importance of VOC control (especially aromatics) to mitigate photochemical pollution in Chengdu. The study deepens the understanding of photochemical pollution in urban areas of western China and further emphasizes the impacts of ONs chemistry on ozone pollution.
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Affiliation(s)
- Chunmeng Li
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, The State Environmental Protection Key Laboratory of Atmospheric Ozone Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Haichao Wang
- School of Atmospheric Sciences, Sun Yat-sen University, Zhuhai 519082, China; Guangdong Provincial Observation and Research Station for Climate Environment and Air Quality Change in the Pearl River Estuary, Key Laboratory of Tropical Atmosphere-Ocean System, Ministry of Education, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519082, China.
| | - Xiaorui Chen
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, The State Environmental Protection Key Laboratory of Atmospheric Ozone Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Tianyu Zhai
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, The State Environmental Protection Key Laboratory of Atmospheric Ozone Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Xuefei Ma
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, The State Environmental Protection Key Laboratory of Atmospheric Ozone Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Xinping Yang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, The State Environmental Protection Key Laboratory of Atmospheric Ozone Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Shiyi Chen
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, The State Environmental Protection Key Laboratory of Atmospheric Ozone Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Xin Li
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, The State Environmental Protection Key Laboratory of Atmospheric Ozone 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, The State Environmental Protection Key Laboratory of Atmospheric Ozone Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Keding Lu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, The State Environmental Protection Key Laboratory of Atmospheric Ozone Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
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3
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Sun M, Zhou Y, Wang Y, Qiao X, Wang J, Zhang J. Heterogeneous Reaction of Peroxyacetyl Nitrate on Real-World PM 2.5 Aerosols: Kinetics, Influencing Factors, and Atmospheric Implications. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:9325-9334. [PMID: 35704858 DOI: 10.1021/acs.est.2c03050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The formation and decomposition of peroxyacetyl nitrate (PAN), an important atmospheric nitrogen oxide reservoir, can impact the level and cycling of free radicals and nitrogen compounds in the atmosphere. PAN sinks are poorly understood, highlighting the importance of elucidating the heterogeneous reaction of PAN on aerosol surfaces. Here, we report for the first time the uptake behavior, kinetics, and potential mechanism of PAN uptake on real-world aerosol PM2.5 using a flow tube system. The uptake coefficients (γ) of PAN increased non-linearly from (1.5 ± 0.7) × 10-5 at 0% relative humidity (RH) to (9.3 ± 2.0) × 10-5 at 80% RH. The γ decrease with increasing initial PAN concentration is consistent with the Langmuir-Hinshelwood mechanism. Organic components of aerosols may promote heterogeneous loss of PAN through redox reactions. Higher γ occurs with higher water content, lower pH, and lower ionic strength in the aqueous phase of aerosols. The present study suggests that heterogeneous reaction of PAN on ambient aerosols plays a non-negligible role in the atmospheric PAN budget and provides new insights into the role of PAN in promoting atmospheric oxidation capacity during hazy periods with cold and wet weather conditions.
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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
- Institute of Environmental Engineering, ETH Zürich, Zürich 8093, Switzerland
| | - 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
| | - Xueqi Qiao
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Jing Wang
- Institute of Environmental Engineering, ETH Zürich, Zürich 8093, Switzerland
- Laboratory for Advanced Analytical Technologies, Empa, Swiss Federal Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland
| | - 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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4
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Li Z, Xie G, Chen H, Zhan B, Wang L, Mu Y, Mellouki A, Chen J. Characterization of peroxyacetyl nitrate (PAN) under different PM 2.5 concentration in wintertime at a North China rural site. J Environ Sci (China) 2022; 114:221-232. [PMID: 35459488 DOI: 10.1016/j.jes.2021.08.040] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/17/2021] [Accepted: 08/17/2021] [Indexed: 06/14/2023]
Abstract
As a secondary pollutant of photochemical pollution, peroxyacetyl nitrate (PAN) has attracted a close attention. A four-month campaign was conducted at a rural site in North China Plain (NCP) including the measurement of PAN, O3, NOx, PM2.5, oxygenated volatile organic compounds (OVOCs), photolysis rate constants of NO2 and O3 and meteorological parameters to investigate the wintertime characterization of photochemistry from November 2018 to February 2019. The results showed that the maximum and mean values of PAN were 4.38 and 0.93 ± 0.67 ppbv during the campaign, respectively. The PAN under different PM2.5 concentrations from below 75 μg/m3 up to 250 μg/m3, showed different diurnal variation and formation rate. In the PM2.5 concentration range of above 250 μg/m3, PAN had the largest daily mean value of 0.64 ppbv and the fastest production rate of 0.33 ppbv/hr. From the perspective of PAN's production mechanism, the light intensity and precursors concentrations under different PM2.5 pollution levels indicated that there were sufficient light intensity and high volatile organic compounds (VOCs) and NOx precursors concentration even under severe pollution level to generate a large amount of PAN. Moreover, the bimodal staggering phenomenon of PAN and PM2.5 provided a basis that PAN might aggravate haze through secondary organic aerosols (SOA) formation.
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Affiliation(s)
- Zhuoyu Li
- Department of Environmental Science & Engineering, Fudan Tyndall Center, Institute of Atmospheric Sciences, Fudan University, Shanghai 200438, China
| | - Guangzhao Xie
- Department of Environmental Science & Engineering, Fudan Tyndall Center, Institute of Atmospheric Sciences, Fudan University, Shanghai 200438, China
| | - Hui Chen
- Department of Environmental Science & Engineering, Fudan Tyndall Center, Institute of Atmospheric Sciences, Fudan University, Shanghai 200438, China
| | - Bixin Zhan
- Department of Environmental Science & Engineering, Fudan Tyndall Center, Institute of Atmospheric Sciences, Fudan University, Shanghai 200438, China
| | - Lin Wang
- Department of Environmental Science & Engineering, Fudan Tyndall Center, Institute of Atmospheric Sciences, Fudan University, Shanghai 200438, China
| | - Yujing Mu
- Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Abdelwahid Mellouki
- Institut de Combustion, Aérothermique, Réactivité et Environnement, Centre National de la Recherche Scientifique, 45071 Orléans cedex 02, France
| | - Jianmin Chen
- Department of Environmental Science & Engineering, Fudan Tyndall Center, Institute of Atmospheric Sciences, Fudan University, Shanghai 200438, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
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Zhang G, Jing S, Xu W, Gao Y, Yan C, Liang L, Huang C, Wang H. Simultaneous observation of atmospheric peroxyacetyl nitrate and ozone in the megacity of Shanghai, China: Regional transport and thermal decomposition. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 274:116570. [PMID: 33529905 DOI: 10.1016/j.envpol.2021.116570] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 01/08/2021] [Accepted: 01/19/2021] [Indexed: 06/12/2023]
Abstract
Atmospheric peroxyacetyl nitrate (PAN) and ozone (O3) are two typical indicators for photochemical pollution that have adverse effects on the ecosystem and human health. Observation networks for these pollutants have been expanding in developed regions of China, such as North China Plain (NCP) and Pearl River Delta (PRD), but are sparse in Yangtze River Delta (YRD), meaning their concentration and influencing factors remain poorly understood. Here, we performed a one-year measurement of atmospheric PAN, O3, particulate matter with aerodynamic diameter smaller than 2.5 μm (PM2.5), nitrogen oxides (NOx), carbon monoxide (CO), and meteorological parameters from December 2016 to November 2017 in Shanghai. Overall, high hourly maximum PAN and O3 were found to be 7.0 and 185 ppbv in summer, 6.2 and 146 ppbv in autumn, 5.8 and 137 ppbv in spring, and 6.0 and 76.7 ppbv in winter, respectively. Continental air masses probably carried atmospheric pollutants to the sampling site, while frequent maritime winds brought in less polluted air masses. Furthermore, positive correlations (R: 0.72-0.85) between PAN and O3 were found in summer, indicating a predominant role of photochemistry in their formation. Unlike in summer, weak or no correlations between PAN and O3 were featured during the other seasons, especially in winter, due to their different loss pathways. Unexpectedly, positive correlations between PAN and PM2.5 were found in all seasons. During summer, moderate correlation could be attributed to the strong photochemistry acting as a common driver in the formation of secondary aerosols and PAN. During winter, high PM2.5 might promote PAN production through HONO production, hence resulting in a good positive correlation. Additionally, the loss of PAN by thermal decomposition (TPAN) only accounted for a small fraction (ca. 1%) of the total (PAN + TPAN) during a typical winter episode, while it significantly reached 14.4 ppbv (71.1% of the total) in summer.
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Affiliation(s)
- Gen Zhang
- State Key Laboratory of Severe Weather & Key Laboratory of Atmospheric Chemistry, Chinese Academy of Meteorological Sciences, Beijing, 100081, China; Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), Nanjing University of Information Science & Technology, Nanjing, 210044, China
| | - Shengao Jing
- State Environmental Protection Key Laboratory of Formation and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai, 200233, China.
| | - Wanyun Xu
- State Key Laboratory of Severe Weather & Key Laboratory of Atmospheric Chemistry, Chinese Academy of Meteorological Sciences, Beijing, 100081, China
| | - Yaqin Gao
- State Environmental Protection Key Laboratory of Formation and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai, 200233, China
| | - Chao Yan
- Institute for Atmospheric and Earth System Research/Physics, Faculty of Science, University of Helsinki, Finland
| | - Linlin Liang
- State Key Laboratory of Severe Weather & Key Laboratory of Atmospheric Chemistry, Chinese Academy of Meteorological Sciences, Beijing, 100081, China
| | - Cheng Huang
- State Environmental Protection Key Laboratory of Formation and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai, 200233, China
| | - Hongli Wang
- State Environmental Protection Key Laboratory of Formation and Prevention of Urban Air Pollution Complex, Shanghai Academy of Environmental Sciences, Shanghai, 200233, China
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Xu W, Zhang G, Wang Y, Tong S, Zhang W, Ma Z, Lin W, Kuang Y, Yin L, Xu X. Aerosol Promotes Peroxyacetyl Nitrate Formation During Winter in the North China Plain. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:3568-3581. [PMID: 33656863 DOI: 10.1021/acs.est.0c08157] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Peroxyacetyl nitrate (PAN) is an important indicator for photochemical pollution, formed similar to ozone in the photochemistry of certain volatile organic compounds (VOCs) in the presence of nitrogen oxides, and has displayed surprisingly high concentrations during wintertime that were better correlated to particulate rather than ozone concentrations, for which the reasons remained unknown. In this study, wintertime observations of PAN, VOCs, PM2.5, HONO, and various trace gases were investigated to find the relationship between aerosols and wintertime PAN formation. Wintertime photochemical pollution was affirmed by the high PAN concentrations (average: 1.2 ± 1.1 ppb, maximum: 7.1 ppb), despite low ozone concentrations. PAN concentrations were determined by its oxygenated VOC (OVOC) precursor concentrations and the NO/NO2 ratios and can be well parameterized based on the understanding of their chemical relationship. Data analysis and box modeling results suggest that PAN formation was mostly contributed by VOC aging processes involving OH oxidation or photolysis rather than ozonolysis pathways. Heterogeneous reactions on aerosols have supplied key photochemical oxidants such as HONO, which produced OH radicals upon photolysis, promoting OVOC formation and thereby enhancing PAN production, explaining the observed PM2.5-OVOC-PAN intercorrelation. In turn, parts of these OVOCs might participate in the formation of secondary organic aerosol, further aggravating haze pollution as a feedback. Low wintertime temperatures enable the long-range transport of PAN to downwind regions, and how that will impact their oxidation capacity and photochemical pollution requires further assessment in future studies.
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Affiliation(s)
- Wanyun Xu
- State Key Laboratory of Severe Weather & Key Laboratory for Atmospheric Chemistry of CMA, Institute of Atmospheric Composition, Chinese Academy of Meteorological Sciences, Beijing 100081, China
| | - Gen Zhang
- State Key Laboratory of Severe Weather & Key Laboratory for Atmospheric Chemistry of CMA, Institute of Atmospheric Composition, Chinese Academy of Meteorological Sciences, Beijing 100081, China
| | - Ying Wang
- State Key Laboratory of Severe Weather & Key Laboratory for Atmospheric Chemistry of CMA, Institute of Atmospheric Composition, Chinese Academy of Meteorological Sciences, Beijing 100081, China
| | - Shengrui Tong
- Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Wenqian Zhang
- Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Zhiqiang Ma
- Institute of Urban Meteorology, China Meteorological Administration, Beijing 100089, China
| | - Weili Lin
- College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China
| | - Ye Kuang
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 510632, China
- Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Jinan University, Guangzhou 510632, China
| | - Liyuan Yin
- State Key Laboratory of Severe Weather & Key Laboratory for Atmospheric Chemistry of CMA, Institute of Atmospheric Composition, Chinese Academy of Meteorological Sciences, Beijing 100081, China
| | - Xiaobin Xu
- State Key Laboratory of Severe Weather & Key Laboratory for Atmospheric Chemistry of CMA, Institute of Atmospheric Composition, Chinese Academy of Meteorological Sciences, Beijing 100081, China
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Yang Y, Xu X, Zhang Y, Zheng S, Wang L, Liu D, Gustave W, Jiang L, Hua Y, Du S, Tang L. Seasonal size distribution and mixing state of black carbon aerosols in a polluted urban environment of the Yangtze River Delta region, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 654:300-310. [PMID: 30445330 DOI: 10.1016/j.scitotenv.2018.11.087] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 11/01/2018] [Accepted: 11/07/2018] [Indexed: 06/09/2023]
Abstract
The optical properties of black carbon aerosols (BC) are determined by the particles size and the associated non-BC materials, which may be source-related or modified during secondary processing. The one-year long monitoring of BC was first conducted using a Single Particle Soot Photometer (SP2) from December 2013 to November 2014 in Nanjing, a megacity in the Yangtze River Delta region of China. The seasonal variation in the BC size distribution and mixing state were investigated. There was no apparent systematic variation in the mean BC core mass median diameter between seasons, as these values were 226 ± 12 nm, 217 ± 13 nm, 211 ± 15 nm and 221 ± 12 nm for winter, spring, summer and autumn respectively. The mixing state of BC was quantified as the bulk relative coating thickness (defined as particle size Dp over core size Dc, Dp/Dc), which ranged from 1.05 to 2.65. The BC was found to be significantly more coated in the winter (Dp/Dc = 1.50 ± 0.30) than in other seasons (Dp/Dc = 1.27 ± 0.09, 1.28 ± 0.10, 1.27 ± 0.11 in spring, summer and autumn respectively). Higher levels of coating during the winter may due to the contributions of the primary source (with the highest BC mass loadings between seasons) or secondary processes such as low temperature that facilitated the condensation. It was found that the photochemical process may enhance the coatings on BC in summer. At nighttime, the reduced and stabilized planetary boundary layer and the nighttime secondary formation may also lead to BC becoming well mixed with other components. Moreover, BC was shown to be less coated when the NOx concentration was high. However, during all seasons, the BC coating was strongly correlated with other non-BC particulate mass, which suggests that at higher pollution levels BC was more significantly coated with other existing materials through coagulation or condensation by other secondary species.
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Affiliation(s)
- Yifan Yang
- Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu Province, China
| | - Xiaofeng Xu
- Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu Province, China.
| | - Yunjiang Zhang
- Institut National de l'Environnement Industriel et des Risques, Verneuil-en-Halatte 60550, France; Laboratoire des Sciences du Climat et de l'Environnement, CNRS-CEA-UVSQ, Université Paris-Saclay, Gif sur Yvette 91191, France
| | - Shanshan Zheng
- Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu Province, China
| | - Lingrui Wang
- Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu Province, China
| | - Dantong Liu
- Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou 310058, China; Centre for Atmospheric Science, School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester M139PL, UK
| | - Williamson Gustave
- Department of Environment Science, Xi'an Jiangtong Liverpoor University, Suzhou 215123, China
| | - Lei Jiang
- Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (CICAEET), School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Yan Hua
- Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (CICAEET), School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Songshan Du
- Jiangsu Environmental Monitoring Center, Nanjing 210036, China
| | - Lili Tang
- Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology (CICAEET), School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, China; Jiangsu Environmental Monitoring Center, Nanjing 210036, China
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8
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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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9
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Zhu H, Gao T, Zhang J. Wintertime characteristic of peroxyacetyl nitrate in the Chengyu district of southwestern China. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2018; 25:23143-23156. [PMID: 29860696 DOI: 10.1007/s11356-018-2412-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 05/24/2018] [Indexed: 06/08/2023]
Abstract
Atmospheric concentrations of peroxyacetyl nitrate (PAN) were measured in Ziyang in December 2012 to provide basic knowledge of PAN in the Chengyu district and offer recommendations for air pollution management. The PAN pollution was relatively severe in Ziyang in winter, with the maximum and average PAN concentrations of 1.61 and 0.55 ppbv, respectively, and a typical single-peak diurnal trend in PAN and theoretical PAN lost by thermal decomposition (TPAN) were observed. PAN and O3 concentrations were correlated (R2 = 0.52) and the ratios of daily maximum PAN to O3 ([PAN]/[O3] ratio) ranged from 0.013 to 0.108, with an average of 0.038. Both acetone and methyl ethyl ketone (MEK) were essential for producing the acetylperoxy radicals (PA) and subsequently PAN in Ziyang in winter, and PAN concentrations at the sampling site exhibited more sensitivity to volatile organic compound (VOC) concentrations than nitrogen oxide (NOx) levels. Therefore, management should focus on reducing VOCs emissions, in particular those that produce acetone and MEK through photolysis and oxidizing reactions. In addition, the influence of relative humidity (RH) on the heterogeneous reactions between PAN and PM2.5 in the atmospheric environment may have led to the strong correlation between observed PM2.5 and PAN in Ziyang in winter. Furthermore, a typical air pollution event was observed on 17-18 December 2012, which Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) and PSCF simulations suggest that it was caused by the local formation and the regional transport of polluted air masses from Hanzhong, Nanchong, and Chengdu.
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Affiliation(s)
- Honglin Zhu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Haidian District, Beijing, 100871, China
| | - Tianyu Gao
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Haidian District, Beijing, 100871, China
| | - Jianbo Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Haidian District, Beijing, 100871, China.
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