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Souza PAF, Kroptavich CR, Zhou S, Kahan TF. Oxidant concentrations and photochemistry in a vehicle cabin. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2024. [PMID: 39058373 DOI: 10.1039/d4em00319e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/28/2024]
Abstract
Indoor air quality (IAQ) in vehicles can be important to people's health, especially for those whose occupations require them to spend extensive time in vehicles. To date, research on vehicle IAQ has primarily focused on direct emissions as opposed to chemistry happening in vehicle cabins. In this work, we conducted time-resolved measurements of the oxidants and oxidant precursors ozone (O3), nitric oxide (NO), nitrogen dioxide (NO2), and nitrous acid (HONO) inside the cabin of a 2012 Toyota Rav4 under varying ventilation conditions (i.e., car off, car on with passive ventilation, car on with mechanical ventilation via the recirculating fan, and car on with mechanical ventilation via the direct fan). Ozone levels inside the vehicle were significantly lower than outdoors under most conditions, and were approximately half the outdoor levels when the direct fan was in operation. Nitric oxide and NO2 concentrations were very low both inside the vehicle and outdoors. Nitrous acid levels in the vehicle were lower than reported values in other indoor environments, though much higher than expected outdoor levels. We also investigated the potential for photochemical production of radicals in the vehicle. Time- and wavelength-resolved solar irradiance spectra were collected, and steady state hydroxyl radical (OH) and nitrate radical (NO3) concentrations were calculated. Steady state OH concentrations were predicted to be similar to those in air masses in residences illuminated by sunlight, suggesting the importance of HONO photolysis in vehicles. Conversely, nitrate radicals (NO3) were not considered significant indoor oxidants in our study due to rapid titration by NO. Overall, our findings emphasize the importance of both air exchange and photochemistry in shaping the composition of air inside vehicles.
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Affiliation(s)
- Pedro A F Souza
- Department of Chemistry, University of Saskatchewan, Saskatoon, SK, Canada.
| | | | - Shan Zhou
- Department of Civil and Environmental Engineering, Rice University, Houston, TX, USA
| | - Tara F Kahan
- Department of Chemistry, University of Saskatchewan, Saskatoon, SK, Canada.
- Department of Chemistry, Syracuse University, Syracuse, NY, USA
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2
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Chong K, Wang Y, Zheng M, Qu H, Zhang R, Lee YR, Ji Y, Huey LG, Fang H, Song W, Fang Z, Liu C, Gao Y, Tang J, Wang X. Observation-Based Diagnostics of Reactive Nitrogen Recycling through HONO Heterogenous Production: Divergent Implications for Ozone Production and Emission Control. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2024; 58:11554-11567. [PMID: 38885439 PMCID: PMC11223480 DOI: 10.1021/acs.est.3c07967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 06/03/2024] [Accepted: 06/04/2024] [Indexed: 06/20/2024]
Abstract
Understanding of nitrous acid (HONO) production is crucial to photochemical studies, especially in polluted environments like eastern China. In-situ measurements of gaseous and particulate compositions were conducted at a rural coastal site during the 2018 spring Ozone Photochemistry and Export from China Experiment (OPECE). This data set was applied to investigate the recycling of reactive nitrogen through daytime heterogeneous HONO production. Although HONO levels increase during agricultural burning, analysis of the observation data does not indicate more efficient HONO production by agricultural burning aerosols than other anthropogenic aerosols. Box and 1-D modeling analyses reveal the intrinsic relationships between nitrogen dioxide (NO2), particulate nitrate (pNO3), and nitric acid (HNO3), resulting in comparable agreement between observed and simulated HONO concentrations with any one of the three heterogeneous HONO production mechanisms, photosensitized NO2 conversion on aerosols, photolysis of pNO3, and conversion from HNO3. This finding underscores the uncertainties in the mechanistic understanding and quantitative parametrizations of daytime heterogeneous HONO production pathways. Furthermore, the implications for reactive nitrogen recycling, ozone (O3) production, and O3 control strategies vary greatly depending on the HONO production mechanism. On a regional scale, the conversion of HONO from pNO3 can drastically enhance O3 production, while the conversion from NO2 can reduce O3 sensitivity to NOx changes in polluted eastern China.
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Affiliation(s)
- Kezhen Chong
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Yuhang Wang
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Mingming Zheng
- School
of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan 430024, China
| | - Hang Qu
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Ruixiong Zhang
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Young Ro Lee
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Yi Ji
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Lewis Gregory Huey
- School
of Earth and Atmospheric Sciences, Georgia
Institute of Technology, Atlanta, Georgia 30332, United States
| | - Hua Fang
- Guangzhou
Institute of Geochemistry, Chinese Academy
of Sciences, Guangzhou 510640, China
| | - Wei Song
- Guangzhou
Institute of Geochemistry, Chinese Academy
of Sciences, Guangzhou 510640, China
| | - Zheng Fang
- Guangzhou
Institute of Geochemistry, Chinese Academy
of Sciences, Guangzhou 510640, China
| | - Cheng Liu
- University
of Science and Technology of China, Hefei 230026, China
| | - Yang Gao
- Key
Laboratory of Marine Environment and Ecology, Ministry of Education
of China, Ocean University of China, Qingdao 266100, China
| | - Jianhui Tang
- Yantai Institute
of Coast Zone Research, CAS, Yantai 264003, China
| | - Xinming Wang
- Guangzhou
Institute of Geochemistry, Chinese Academy
of Sciences, Guangzhou 510640, China
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3
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Lian C, Wang W, Chen Y, Zhang Y, Zhang J, Liu Y, Fan X, Li C, Zhan J, Lin Z, Hua C, Zhang W, Liu M, Li J, Wang X, An J, Ge M. Long-term winter observation of nitrous acid in the urban area of Beijing. J Environ Sci (China) 2022; 114:334-342. [PMID: 35459496 DOI: 10.1016/j.jes.2021.09.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 08/30/2021] [Accepted: 09/03/2021] [Indexed: 06/14/2023]
Abstract
The particulate matter (PM) pollution has been significantly improved by carrying out various valid emission control strategies since 2013 in China. Meanwhile the variation trend of nitrous acid (HONO) is worthy to investigate due to its vital role in the atmospheric oxidation process. In this study, field observation in the winter is conducted to investigate the concentration of HONO in an urban area of Beijing. In the winter of 2019, the mean HONO concentration is 1.38 ppbV during the whole winter. Photo-enhanced NO2 heterogeneous reactions on the ground and aerosol surfaces were found as the possible daytime sources of HONO. Compared to O3, photolysis of HONO dominates the primary OH sources during the winter time. To understand the HONO pollution patterns by years variation, multi-year data is summarized and finds that primary pollutants including CO and NO decreased, but secondary pollutants i.e., HONO (mostly generated via secondary process) increased. Our study highlights the requirement to mitigate secondary pollution by control HONO concentration.
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Affiliation(s)
- Chaofan Lian
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Weigang Wang
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of the Chinese Academy of Sciences, Beijing 100049, China.
| | - Yan Chen
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Yusheng Zhang
- Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Jingwei Zhang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences, Beijing 100029, China
| | - Yongchun Liu
- Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China.
| | - Xiaolong Fan
- Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Chang Li
- Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Junlei Zhan
- Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Zhuohui Lin
- Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Chenjie Hua
- Aerosol and Haze Laboratory, Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Wenyu Zhang
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Mingyuan Liu
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Junling Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Xuefei Wang
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Junling An
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences, Beijing 100029, China; University of the Chinese Academy of Sciences, Beijing 100049, China; Center for Excellence in Urban Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Maofa Ge
- State Key Laboratory for Structural Chemistry of Unstable and Stable Species, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China; University of the Chinese Academy of Sciences, Beijing 100049, China; Center for Excellence in Urban Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
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4
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Yang W, Han C, Zhang T, Tang N, Yang H, Xue X. Heterogeneous photochemical uptake of NO 2 on the soil surface as an important ground-level HONO source. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2021; 271:116289. [PMID: 33383427 DOI: 10.1016/j.envpol.2020.116289] [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: 08/05/2020] [Revised: 12/09/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
Nitrous acid (HONO) production from the heterogeneous photochemical reaction of NO2 on several Chinese soils was performed in a cylindrical reactor at atmospheric pressure. The NO2 uptake coefficient (γ) and HONO yield (YHONO) on different soils were (0.42-5.16) × 10-5 and 6.3%-69.6%, respectively. Although the photo-enhanced uptake of NO2 on different soils was observed, light could either enhance or inhibit the conversion efficiency of NO2 to HONO, depending on the properties of the soils. Soils with lower pH generally had larger γ and YHONO. Soil organics played a key role in HONO formation through the photochemical uptake of NO2 on soil surfaces. The γ showed a positive correlation with irradiation and temperature, while it exhibited a negative relationship with relative humidity (RH). YHONO inversely depended on the soil mass (0.32-3.25 mg cm-2), and it positively relied on the irradiance and RH (7%-22%). There was a maximum value for YHONO at 298 K. Based on the experimental results, HONO source strengths from heterogeneous photochemical reaction of NO2 on the soil surfaces were estimated to be 0.2-2.7 ppb h-1 for a mixing layer height of 100 m, which could account for the missing daytime HONO sources in most areas.
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Affiliation(s)
- Wangjin Yang
- School of Metallurgy, Northeastern University, Shenyang, 110819, China
| | - Chong Han
- School of Metallurgy, Northeastern University, Shenyang, 110819, China.
| | - Tingting Zhang
- School of Metallurgy, Northeastern University, Shenyang, 110819, China
| | - Ning Tang
- Institute of Nature and Environmental Technology, Kanazawa University, Kanazawa, 920-1192, Japan
| | - He Yang
- School of Metallurgy, Northeastern University, Shenyang, 110819, China
| | - Xiangxin Xue
- School of Metallurgy, Northeastern University, Shenyang, 110819, China
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5
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Affiliation(s)
- Jiajue Chai
- Department of Earth, Environmental and Planetary Sciences and Institute at Brown for Environment and Society, Brown University, Providence, Rhode Island 02912, United States
| | - Meredith G. Hastings
- Department of Earth, Environmental and Planetary Sciences and Institute at Brown for Environment and Society, Brown University, Providence, Rhode Island 02912, United States
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6
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Scharko NK, Martin ET, Losovyj Y, Peters DG, Raff JD. Evidence for Quinone Redox Chemistry Mediating Daytime and Nighttime NO 2-to-HONO Conversion on Soil Surfaces. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:9633-9643. [PMID: 28742971 DOI: 10.1021/acs.est.7b01363] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Humic acid (HA) is thought to promote NO2 conversion to nitrous acid (HONO) on soil surfaces during the day. However, it has proven difficult to identify the reactive sites in natural HA substrates. The mechanism of NO2 reduction on soil surrogates composed of HA and clay minerals was studied by use of a coated-wall flow reactor and cavity-enhanced spectroscopy. Conversion of NO2 to HONO in the dark was found to be significant and correlated to the abundance of C-O moieties in HA determined from the X-ray photoelectron spectra of the C 1s region. Twice as much HONO was formed when NO2 reacted with HA that was photoreduced by irradiation with UV-visible light compared to the dark reaction; photochemical reactivity was correlated to the abundance of C═O moieties rather than C-O groups. Bulk electrolysis was used to generate HA in a defined reduction state. Electrochemically reduced HA enhanced NO2-to-HONO conversion by a factor of 2 relative to non-reduced HA. Our findings suggest that hydroquinones and benzoquinones, which are interchangeable via redox equilibria, contribute to both thermal and photochemical HONO formation. This conclusion is supported by experiments that studied NO2 reactivity on mineral surfaces coated with the model quinone, juglone. Results provide further evidence that redox-active sites on soil surfaces drive ground-level NO2-to-nitrite conversion in the atmospheric boundary layer throughout the day, while amphoteric mineral surfaces promote the release of nitrite formed as gaseous HONO.
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Affiliation(s)
- Nicole K Scharko
- School of Public and Environmental Affairs, Indiana University , 1315 East 10th Street, Bloomington, Indiana 47405, United States
| | - Erin T Martin
- Department of Chemistry, Indiana University , 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Yaroslav Losovyj
- Department of Chemistry, Indiana University , 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Dennis G Peters
- Department of Chemistry, Indiana University , 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Jonathan D Raff
- School of Public and Environmental Affairs, Indiana University , 1315 East 10th Street, Bloomington, Indiana 47405, United States
- Department of Chemistry, Indiana University , 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
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7
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Liang Y, Zha Q, Wang W, Cui L, Lui KH, Ho KF, Wang Z, Lee SC, Wang T. Revisiting nitrous acid (HONO) emission from on-road vehicles: A tunnel study with a mixed fleet. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2017; 67:797-805. [PMID: 28278037 DOI: 10.1080/10962247.2017.1293573] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 02/04/2017] [Indexed: 06/06/2023]
Abstract
UNLABELLED Nitrous acid (HONO) is an important precursor of OH radicals in the atmosphere. In urban areas, emissions from vehicles are the main source of air pollutants, including reactive nitrogen. Previously reported emission ratios of HONO (HONO/NOx) from vehicles were measured in the late 1990s and need to be updated due to the significant changes in emission control technologies. We measured the emission ratio of a fleet of vehicles (38% diesel on average) from March 11 to 21, 2015, in a road tunnel in Hong Kong. The emission ratio of 1.24% (±0.35%) obtained is greater than the commonly adopted 0.8% or 0.3%. The elevated emission ratio is found to be related to the presence of vehicles equipped with diesel particle filters (DPFs). Positive correlation between HONO and black carbon (BC) shows that HONO and BC were emitted together, while the lack of correlation or even anticorrelation between HONO/NOx and BC indicates that the BC-mediated conversion of NO2 to HONO in the dark was insignificant in the immediate vicinity of the emission sources. IMPLICATIONS Vehicular emission is a key source for HONO in the urban atmosphere. However, the most commonly used emission ratio HONO/NOx in modeling studies was measured more than 15 years ago. Our tunnel study suggests that a mixed fleet nowadays has a higher emission ratio, possibly because of the diesel particle filter (DPF) retrofit program and the growing share of Euro IV or more advanced diesel vehicles. Our study also provides new insight into the role of black carbon in HONO formation from vehicles.
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Affiliation(s)
- Yutong Liang
- a Department of Civil and Environmental Engineering , The Hong Kong Polytechnic University , Hong Kong , People's Republic of China
| | - Qiaozhi Zha
- a Department of Civil and Environmental Engineering , The Hong Kong Polytechnic University , Hong Kong , People's Republic of China
| | - Weihao Wang
- a Department of Civil and Environmental Engineering , The Hong Kong Polytechnic University , Hong Kong , People's Republic of China
| | - Long Cui
- a Department of Civil and Environmental Engineering , The Hong Kong Polytechnic University , Hong Kong , People's Republic of China
| | - Ka Hei Lui
- b Jockey Club School of Public Health and Primary Care , The Chinese University of Hong Kong , Hong Kong , People's Republic of China
| | - Kin Fai Ho
- b Jockey Club School of Public Health and Primary Care , The Chinese University of Hong Kong , Hong Kong , People's Republic of China
| | - Zhe Wang
- a Department of Civil and Environmental Engineering , The Hong Kong Polytechnic University , Hong Kong , People's Republic of China
| | - Shun-Cheng Lee
- a Department of Civil and Environmental Engineering , The Hong Kong Polytechnic University , Hong Kong , People's Republic of China
| | - Tao Wang
- a Department of Civil and Environmental Engineering , The Hong Kong Polytechnic University , Hong Kong , People's Republic of China
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8
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Wang J, Zhang X, Guo J, Wang Z, Zhang M. Observation of nitrous acid (HONO) in Beijing, China: Seasonal variation, nocturnal formation and daytime budget. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 587-588:350-359. [PMID: 28237466 DOI: 10.1016/j.scitotenv.2017.02.159] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 02/12/2017] [Accepted: 02/18/2017] [Indexed: 06/06/2023]
Abstract
Seasonal characteristics of atmospheric nitrous acid (HONO) were investigated with high time-resolution field measurements at an urban site of Beijing in four select months (representing four different seasons) from September 2015 to July 2016. The HONO concentrations displayed a pronounced seasonal profile with a maximum in autumn (2.27±1.82ppb) and a minimum in winter (1.05±0.89ppb). Significant diurnal cycles were also observed during the whole campaign. We found that the nighttime build-up of HONO was attributed to the heterogeneous conversion of NO2 on wet surface. The calculated NO2 to HONO conversion frequencies varied from 0.005h-1 in spring to 0.010h-1 in summer, with an average value of 0.008h-1. The seasonality of these conversion frequencies was closely related to the RH levels in different seasons. During daytime, large additional HONO sources were calculated. The noontime additional source was the highest in autumn 3.82ppbh-1, followed by summer 3.05ppbh-1, spring 2.63ppbh-1 and winter 1.30ppbh-1. Correlation studies between the additional HONO source and related parameters demonstrated that the controlling processes responsible for HONO daytime formation varied in different seasons, and that the photo-enhanced formation on wet surface or the photolysis of adsorbed nitric acid and nitrate could be potential HONO sources in Beijing.
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Affiliation(s)
- Jiaqi Wang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaoshan Zhang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Jia Guo
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
| | - Zhangwei Wang
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Meigen Zhang
- University of Chinese Academy of Sciences, Beijing 100049, China; State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences, Beijing 100029, PR China
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9
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Finlayson-Pitts BJ. Introductory lecture: atmospheric chemistry in the Anthropocene. Faraday Discuss 2017; 200:11-58. [DOI: 10.1039/c7fd00161d] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The term “Anthropocene” was coined by Professor Paul Crutzen in 2000 to describe an unprecedented era in which anthropogenic activities are impacting planet Earth on a global scale. Greatly increased emissions into the atmosphere, reflecting the advent of the Industrial Revolution, have caused significant changes in both the lower and upper atmosphere. Atmospheric reactions of the anthropogenic emissions and of those with biogenic compounds have significant impacts on human health, visibility, climate and weather. Two activities that have had particularly large impacts on the troposphere are fossil fuel combustion and agriculture, both associated with a burgeoning population. Emissions are also changing due to alterations in land use. This paper describes some of the tropospheric chemistry associated with the Anthropocene, with emphasis on areas having large uncertainties. These include heterogeneous chemistry such as those of oxides of nitrogen and the neonicotinoid pesticides, reactions at liquid interfaces, organic oxidations and particle formation, the role of sulfur compounds in the Anthropocene and biogenic–anthropogenic interactions. A clear and quantitative understanding of the connections between emissions, reactions, deposition and atmospheric composition is central to developing appropriate cost-effective strategies for minimizing the impacts of anthropogenic activities. The evolving nature of emissions in the Anthropocene places atmospheric chemistry at the fulcrum of determining human health and welfare in the future.
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10
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Kebede MA, Bish DL, Losovyj Y, Engelhard MH, Raff JD. The Role of Iron-Bearing Minerals in NO2 to HONO Conversion on Soil Surfaces. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:8649-60. [PMID: 27409359 DOI: 10.1021/acs.est.6b01915] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Nitrous acid (HONO) accumulates in the nocturnal boundary layer where it is an important source of daytime hydroxyl radicals. Although there is clear evidence for the involvement of heterogeneous reactions of NO2 on surfaces as a source of HONO, mechanisms remain poorly understood. We used coated-wall flow tube measurements of NO2 reactivity on environmentally relevant surfaces (Fe (hydr)oxides, clay minerals, and soil from Arizona and the Saharan Desert) and detailed mineralogical characterization of substrates to show that reduction of NO2 by Fe-bearing minerals in soil can be a more important source of HONO than the putative NO2 hydrolysis mechanism. The magnitude of NO2-to-HONO conversion depends on the amount of Fe(2+) present in substrates and soil surface acidity. Studies examining the dependence of HONO flux on substrate pH revealed that HONO is formed at soil pH < 5 from the reaction between NO2 and Fe(2+)(aq) present in thin films of water coating the surface, whereas in the range of pH 5-8 HONO stems from reaction of NO2 with structural iron or surface complexed Fe(2+) followed by protonation of nitrite via surface Fe-OH2(+) groups. Reduction of NO2 on ubiquitous Fe-bearing minerals in soil may explain HONO accumulation in the nocturnal boundary layer and the enhanced [HONO]/[NO2] ratios observed during dust storms in urban areas.
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Affiliation(s)
| | | | | | - Mark H Engelhard
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory , Richland, Washington 99354, United States
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11
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Crilley LR, Kramer L, Pope FD, Whalley LK, Cryer DR, Heard DE, Lee JD, Reed C, Bloss WJ. On the interpretation of in situ HONO observations via photochemical steady state. Faraday Discuss 2016; 189:191-212. [DOI: 10.1039/c5fd00224a] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A substantial body of recent literature has shown that boundary layer HONO levels are higher than can be explained by simple, established gas-phase chemistry, to an extent that implies that additional HONO sources represent a major, or the dominant, precursor to OH radicals in such environments. This conclusion may be reached by analysis of point observations of (for example) OH, NO and HONO, alongside photochemical parameters; however both NO and HONO have non-negligible atmospheric lifetimes, so these approaches may be problematic if substantial spatial heterogeneity exists. We report a new dataset of HONO, NOx and HOx observations recorded at an urban background location, which support the existence of additional HONO sources as determined elsewhere. We qualitatively evaluate the possible impacts of local heterogeneity using a series of idealised numerical model simulations, building upon the work of Lee et al. (J. Geophys. Res., 2013, DOI: 10.1002/2013JD020341). The simulations illustrate the time required for photostationary state approaches to yield accurate results following substantial perturbations in the HOx/NOx/NOy chemistry, and the scope for bias to an inferred HONO source from NOx and VOC emissions in either a positive or negative sense, depending upon the air mass age following emission. To assess the extent to which these impacts may be present in actual measurements, we present exploratory spatially resolved measurements of HONO and NOx abundance obtained using a mobile instrumented laboratory. Measurements of the spatial variability of HONO in urban, suburban and rural environments show pronounced changes in abundance are found in proximity to major roads within urban areas, indicating that photo-stationary steady state (PSS) analyses in such areas are likely to be problematic. The measurements also show areas of very homogeneous HONO and NOx abundance in rural, and some suburban, regions, where the PSS approach is likely to be valid. Implications for future exploration of HONO production mechanisms are discussed.
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Affiliation(s)
- Leigh R. Crilley
- School of Geography
- Earth & Environmental Sciences
- University of Birmingham
- UK
| | - Louisa Kramer
- School of Geography
- Earth & Environmental Sciences
- University of Birmingham
- UK
| | - Francis D. Pope
- School of Geography
- Earth & Environmental Sciences
- University of Birmingham
- UK
| | - Lisa K. Whalley
- School of Chemistry
- University of Leeds
- UK
- National Centre for Atmospheric Science
- UK
| | | | - Dwayne E. Heard
- School of Chemistry
- University of Leeds
- UK
- National Centre for Atmospheric Science
- UK
| | - James D. Lee
- Wolfson Atmospheric Chemistry Laboratory
- Department of Chemistry
- University of York
- UK
- National Centre for Atmospheric Science
| | - Christopher Reed
- Wolfson Atmospheric Chemistry Laboratory
- Department of Chemistry
- University of York
- UK
| | - William J. Bloss
- School of Geography
- Earth & Environmental Sciences
- University of Birmingham
- UK
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