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Huang S, Shen Z, Yang X, Bai G, Zhang L, Zeng Y, Sun J, Xu H, Ho SSH, Zhang Y, Cao J. Nitroaromatic compounds in six major Chinese cities: Influence of different formation mechanisms on light absorption properties. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 930:172672. [PMID: 38663628 DOI: 10.1016/j.scitotenv.2024.172672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2024] [Revised: 04/19/2024] [Accepted: 04/19/2024] [Indexed: 05/05/2024]
Abstract
Nitroaromatic compounds (NACs) are important nitrogen organics in aerosol with strong light-absorbing and chemically reactive properties. In this study, NACs in six Chinese megacities, including Harbin (HB), Beijing (BJ), Xi'an (XA), Wuhan (WH), Chengdu (CD), and Guangzhou (GZ), were investigated for understanding their sources, gas-particle partitioning, and impact on BrC absorption properties. The concentrations of ΣNACs in PM2.5 in the six cities ranged from 9.15 to 158.8 ng/m3 in winter and from 2.02 to 9.39 ng/m3 in summer. Nitro catechols (NCs), nitro phenols (NPs), and nitro salicylic acids (NSAs) are the main components in ΣNACs, with NCs being dominant in particulate phase and NPs being dominant in the gas phase. Correlation analysis between different pollutant species revealed that coal and biomass combustions were the major sources of NACs in the northern cities during wintertime, while secondary formation dominated NACs in the southern cities during summertime. The contribution of ΣNACs to brown carbon (BrC) light absorption ranged from 0.85 to 7.98 % during the wintertime and 2.07-6.44 % during the summertime. The mass absorption efficiency at 365 nm (MAE365) were highest for 4-nitrocatechol (4NC, 17.4-89.0 m2/g), 4-methyl-5-nitrocatechol (4M5NC, 15.0-76.9 m2/g), and 4-nitroguaiacol (4NG, 11.7-59.8 m2/g). The formation of NCs and NG through oxidation and nitration of catechol and guaiacol led to a significant increase in aerosol light absorption. In contrast, NPs and NSAs formed by the photonitration and photooxidation in liquid phase showed high polarity but low light absorption ability, and the proportions of (NPs + NSAs) in the light absorption of ΣNACs were lower than 15.3 % in the six megacities.
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Affiliation(s)
- Shasha Huang
- Department of Environmental Sciences and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Zhenxing Shen
- Department of Environmental Sciences and Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Xueting Yang
- Department of Environmental Sciences and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Gezi Bai
- Department of Environmental Sciences and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Leiming Zhang
- Air Quality Research Division, Science and Technology Branch, Environment and Climate Change Canada, Toronto, Canada
| | - Yaling Zeng
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Jian Sun
- Department of Environmental Sciences and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Hongmei Xu
- Department of Environmental Sciences and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Steven Sai Hang Ho
- Division of Atmospheric Sciences, Desert Research Institute, Reno NV89512, United States
| | - Ying Zhang
- Instruments Analysis Center of Xi'an Jiaotong University, Xi'an 710049, China
| | - Junji Cao
- Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
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Rana A, Sarkar S. The role of nitroaromatic compounds (NACs) in constraining BrC absorption in the Indo-Gangetic Plain (IGP). THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170523. [PMID: 38296066 DOI: 10.1016/j.scitotenv.2024.170523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 01/09/2024] [Accepted: 01/26/2024] [Indexed: 02/04/2024]
Abstract
We present here the first measurements of nitroaromatic compounds (NACs) including nitrophenols (NPs), nitrocatechols (NCs) and nitrosalicylic acids (NSAs) from the Indian subcontinent and their role in constraining brown carbon (BrC) absorption. NACs at a rural receptor site in the eastern Indo-Gangetic Plain (IGP) (annual average: 185 ± 94 ng m-3) was dominated by NSAs (135 ± 77 ng m-3), followed by NPs (29 ± 11 ng m-3) and NCs (17 ± 16 ng m-3), with notable enrichments during nighttime and during the biomass burning seasons. An equilibrium absorption partitioning model estimated that >90 % of NSAs and NCs were in the particle-phase, suggesting lower degradation rates via oxidation and photolysis potentially due to year-round high relative humidity. While the contribution of NACs to organic aerosol mass was only 0.42 ± 0.23 %, their contribution to BrC absorption in the 300-450 nm range was higher by an order of magnitude (8 ± 4 %), with NCs and NSAs contributing almost equally in the low-visible (400-450 nm) range as at 365 nm. Despite having mass concentrations lower than NPs by factors of ∼2, contribution of NCs to BrC absorption at λ ≥ 400 nm was comparable to that by NPs, indicating the importance of the absorption efficiency of chromophores. The receptor model positive matrix factorization (PMF) quantified three major NAC sources: fossil fuel combustion (49 ± 15 %; annual average), secondary formation (40 ± 12 %), and biomass burning (11 ± 9 %), with variable contributions on seasonal and day-night bases. In summary, the study uncovered the significant role of NACs in constraining BrC absorption in the IGP, which stresses the importance for molecular-level characterization of BrC chromophores.
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Affiliation(s)
- Archita Rana
- Department of Earth Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur, 741246, Nadia, India
| | - Sayantan Sarkar
- School of Civil and Environmental Engineering, Indian Institute of Technology (IIT) Mandi, Kamand, Himachal Pradesh, 175005, India.
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Guo Z, Hu X, Sun W, Peng X, Fu Y, Liu K, Liu F, Meng H, Zhu Y, Zhang G, Wang X, Xue L, Wang J, Wang X, Peng P, Bi X. Mixing state and influence factors controlling diurnal variation of particulate nitrophenol compounds at a suburban area in northern China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 344:123368. [PMID: 38246217 DOI: 10.1016/j.envpol.2024.123368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 12/28/2023] [Accepted: 01/14/2024] [Indexed: 01/23/2024]
Abstract
Nitrophenols have received extensive attention due to their strong light-absorbing ability in the near-ultraviolet-visible region, which could be influenced by the atmospheric processes of nitrophenols. However, our knowledge and understanding of the formation and evolution of nitrophenols are still in the nascent stages. In the present study, the mixing states of four mononitrophenol particles (i.e., nitrophenol, methynitrophenol, nitrocatechol, and methoxynitrophenol), and one nitropolycyclic aromatic hydrocarbon particles (i.e., nitronaphthol (NN)) were investigated using a single-particle aerosol mass spectrometer (SPAMS) in November 2019 in Qingdao, China. The results showed, for the first time, that mononitrophenols and NN exhibit different mixing states and diurnal variations. Four mononitrophenols were internally mixed well with each other, and with organic acids, nitrates, potassium, and naphthalene. The diurnal variation in the number fraction of mononitrophenols presented two peaks at 07:00 to 09:00 and 18:00 to 20:00, and a valley at noon. Atmospheric environmental conditions, including NO2, O3, relative humidity, and temperature, can significantly influence the diurnal variation of mononitrophenols. Multiple linear regression and random forest regression models revealed that the main factors controlling the diurnal variation of mononitrophenols were photochemical reactions during the day and aqueous-phase reactions during the night. Unlike mononitrophenols, about 62-83% of NN were internally mixed with [NH4]+ and [H(NO3)2]-, but not with organic acids and potassium. The diurnal variation of NN was also different from that of mononitrophenols, generally increased from 17:00 to 10:00 and then rapidly decreaed from 11:00 to 16:00. These results imply that NN may have sources and atmospheric processes that are different from mononitrophenols. We speculate that this is mostly controlled by photochemical reactions and mixing with [NH4]+, which may influence the diurnal variation of NN in the ambient particles; however, this requires further confirmation. These findings extend our current understanding of the atmospheric formation and evolution of nitrophenols.
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Affiliation(s)
- Ziyong Guo
- State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China; College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan, 030024, PR China
| | - Xiaodong Hu
- State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China
| | - Wei Sun
- State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China
| | - Xiaocong Peng
- State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China
| | - Yuzhen Fu
- State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China
| | - Kun Liu
- State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China
| | - Fengxian Liu
- School of Economics and Management, Taiyuan University of Technology, Taiyuan, 030024, PR China
| | - He Meng
- Qingdao Eco-environment Monitoring Center of Shandong Province, Qingdao, 266003, PR China
| | - Yujiao Zhu
- Environment Research Institute, Shandong University, Qingdao, 266237, PR China
| | - Guohua Zhang
- State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China; Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China
| | - Xinfeng Wang
- Environment Research Institute, Shandong University, Qingdao, 266237, PR China
| | - Likun Xue
- Environment Research Institute, Shandong University, Qingdao, 266237, PR China
| | - Jiancheng Wang
- College of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan, 030024, PR China
| | - Xinming Wang
- State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China; Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China
| | - Ping'an Peng
- State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China; Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China
| | - Xinhui Bi
- State Key Laboratory of Organic Geochemistry and Guangdong Provincial Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China; Guangdong-Hong Kong-Macao Joint Laboratory for Environmental Pollution and Control, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, PR China.
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Huang S, Yang X, Xu H, Zeng Y, Li D, Sun J, Ho SSH, Zhang Y, Cao J, Shen Z. Insights into the nitroaromatic compounds, formation, and light absorption contributing emissions from various geological maturity coals. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 870:162033. [PMID: 36746281 DOI: 10.1016/j.scitotenv.2023.162033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/31/2023] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
Nitroaromatic compounds (NACs) are essential components of atmospheric organic aerosols. Coal combustion is a key source of atmospheric NACs. In this study, a triple-quadrupole liquid chromatography-mass spectrometry (LC-MS) system was used to identify ten individual NAC emitted in combustions of chunk coal and its briquette at different maturity levels. The Gaussian calculation was applied to quantify the absorption contribution of NACs to brown carbon (BrC). The emission factors (EFs) of total quantified NACs (ΣNACs) are 21.80-4429.55 μg/kg. 4-Nitrocatechol (4NC) is the most abundant NACs, accounting for 25.5-82.3 % of the ΣNACs and has the largest contribution to light absorption (0.34-29.23 %). The EFs for ΣNACs of chunk coal are 1.1-3.0 times those of its briquette, while the coal with volatile matter (VM) = 35.83 % shows the highest NAC emissions. The reaction pathway analysis demonstrates that NACs in briquette are generated through the pyrolysis of coal tar at an early stage of coal combustion, while volatile organic compounds (VOCs) that are emitted in chunk coal contribute greatly to the formations of NACs. The molecular properties analysis reveals that ΣNACs contribute 0.47-35.27 % to BrC light absorption. Anthracite coal (VM = 8.01 %) demonstrates the lowest light absorption coefficient (babs-365). Since bituminous coal (with VM = ~10 %-40 %) is popularly used for heating in rural China in winter, the results of this study could assist to evaluate the climate and environmental impacts on the NACs emission from coal combustion on a regional scale. Finally, the results highlighted that replacements of bituminous by clear fuel (such as chunk or briquette anthracite) could reduce NACs emission effectively.
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Affiliation(s)
- Shasha Huang
- Department of Environmental Sciences and Engineering, Xi'an Jiaotong University, Xi'an 710049, China; The State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710049, China
| | - Xueting Yang
- Department of Environmental Sciences and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Hongmei Xu
- Department of Environmental Sciences and Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Yaling Zeng
- School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
| | - Dan Li
- Department of Environmental Sciences and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Jian Sun
- Department of Environmental Sciences and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Steven Sai Hang Ho
- Divison of Atmospheric Sciences, Desert Research Institute, Reno, NV 89512, United States
| | - Ying Zhang
- Instruments Analysis Center of Xi'an Jiaotong University, Xi'an 710049, China
| | - Junji Cao
- The State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710049, China
| | - Zhenxing Shen
- Department of Environmental Sciences and Engineering, Xi'an Jiaotong University, Xi'an 710049, China; The State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710049, China.
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Li GB, Cai SH, Long B. New Reactions for the Formation of Organic Nitrate in the Atmosphere. ACS OMEGA 2022; 7:39671-39679. [PMID: 36385897 PMCID: PMC9647854 DOI: 10.1021/acsomega.2c03321] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 09/30/2022] [Indexed: 05/24/2023]
Abstract
Organic nitrates make an important contribution to the formation of secondary organic aerosols, but the formation mechanisms of organic nitrates are not fully understood at the molecular level. In the present work, we explore a new route for the formation of organic nitrates in the reaction of formaldehyde (HCHO) with nitric acid (HNO3) catalyzed by water (H2O), ammonia (NH3), and dimethylamine ((CH3)2NH) using theoretical methods. The present results using CCSD(T)-F12a/cc-pVTZ-F12//M06-2X/MG3S unravel that dimethylamine has a stronger catalytic ability in the reaction of HCHO with HNO3, reducing the barrier by 21.97 kcal/mol, while water and ammonia only decrease the energy barrier by 7.35 and 13.56 kcal/mol, respectively. In addition, the calculated kinetics combined with the corresponding concentrations of these species show that the HCHO + HNO3 + (CH3)2NH reaction can compete well with the naked HCHO + HNO3 reaction at 200-240 K, which may make certain contributions to the formation of organic nitrates under some atmospheric conditions.
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Affiliation(s)
- Gang-Biao Li
- Department
of Physics, Guizhou University, Guiyang550025, China
| | - Shao-Hong Cai
- Department
of Physics, Guizhou University, Guiyang550025, China
| | - Bo Long
- Department
of Physics, Guizhou University, Guiyang550025, China
- College
of Materials Science and Engineering, Guizhou
Minzu university, Guiyang550025, China
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Resolving the amine-promoted hydrolysis mechanism of N 2O 5 under tropospheric conditions. Proc Natl Acad Sci U S A 2022; 119:e2205668119. [PMID: 36122231 PMCID: PMC9522417 DOI: 10.1073/pnas.2205668119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Hydrolysis of N2O5 under tropospheric conditions plays a critical role in assessing the fate of O3, OH, and NOx in the atmosphere. However, its removal mechanism has not been fully understood, and little is known about the role of entropy. Herein, we propose a removal path of N2O5 on the water clusters/droplet with the existence of amine, which entails a low free-energy barrier of 4.46 and 3.76 kcal/mol on a water trimer and droplet, respectively, at room temperature. The free-energy barrier exhibits strong temperature dependence; a barrierless hydrolysis process of N2O5 at low temperature (≤150 K) is observed. By coupling constrained ab initio molecular dynamics (constrained AIMD) simulations with thermodynamic integration methods, we quantitively evaluated the entropic contributions to the free energy and compared NH3-, methylamine (MA)-, and dimethylamine (DMA)-promoted hydrolysis of N2O5 on water clusters and droplet. Our results demonstrate that methylation of NH3 stabilizes the product state and promotes hydrolysis of N2O5 by reducing the free-energy barriers. Furthermore, a quantitative analysis of the internal coordinate distribution of the reaction center and the relative position of surrounding species reveals that the significant entropic contribution primarily results from the ensemble effect of configurations observed in the AIMD simulations. Such an ensemble effect becomes more significant with more water molecules included. Lowering the temperature effectively minimizes the entropic contribution, making the hydrolysis more exothermic and barrierless. This study sheds light on the importance of the promoting effect of amines and the entropic effect on gas-phase hydrolysis reactions, which may have far-reaching implications in atmospheric chemistry.
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Zhu M, Huang M, Xue B, Cai S, Hu C, Zhao W, Gu X, Zhang W. Chemical analysis of nitro‐aromatic compounds of secondary organic aerosol formed from photooxidation of p‐xylene with NO
x. J CHIN CHEM SOC-TAIP 2021. [DOI: 10.1002/jccs.202100105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Min‐Cong Zhu
- Fujian Provincial Key Laboratory of Modern Analytical Science and Separation Technology, College of Chemistry and Chemical Engineering and Environment Minnan Normal University Zhangzhou China
| | - Ming‐Qiang Huang
- Fujian Provincial Key Laboratory of Modern Analytical Science and Separation Technology, College of Chemistry and Chemical Engineering and Environment Minnan Normal University Zhangzhou China
| | - Bing‐Bing Xue
- Fujian Provincial Key Laboratory of Modern Analytical Science and Separation Technology, College of Chemistry and Chemical Engineering and Environment Minnan Normal University Zhangzhou China
| | - Shun‐You Cai
- Fujian Provincial Key Laboratory of Modern Analytical Science and Separation Technology, College of Chemistry and Chemical Engineering and Environment Minnan Normal University Zhangzhou China
| | - Chang‐Jin Hu
- Laboratory of Atmospheric Physico‐Chemistry, Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences Hefei China
| | - Wei‐Xiong Zhao
- Laboratory of Atmospheric Physico‐Chemistry, Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences Hefei China
| | - Xue‐Jun Gu
- Laboratory of Atmospheric Physico‐Chemistry, Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences Hefei China
| | - Wei‐Jun Zhang
- Laboratory of Atmospheric Physico‐Chemistry, Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences Hefei China
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