Article
Chemistry, Physical
Li Xu, Narcisse T. Tsona, Lin Du
Summary: This study reveals that high relative humidity enhances the contribution of SO2 to the formation of OSs, particularly HOOSs, during monoterpene ozonolysis in the atmosphere. The interaction between SO2 and ROOHs under high humidity conditions promotes the formation of HOOSs, leading to changes in SOA yield. Additionally, variations in particle acidity and liquid water content also impact SOA formation.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Environmental Sciences
Junling Li, Kun Li, Hao Zhang, Xin Zhang, Yuanyuan Ji, Wanghui Chu, Yuxue Kong, Yangxi Chu, Yanqin Ren, Yujie Zhang, Haijie Zhang, Rui Gao, Zhenhai Wu, Fang Bi, Xuan Chen, Xuezhong Wang, Weigang Wang, Hong Li, Maofa Ge
Summary: Vehicle exhaust is a major source of air pollutants in urban areas, containing a complex mixture of organic vapours. This study investigates the photooxidation of vehicle emissions in the presence of NOx and SO2, and finds that ozone formation is influenced by temperature and OH concentration, but not significantly affected by SO2 concentration. However, SO2 enhances particle formation and promotes the formation of organo-sulfates. These findings provide a scientific basis for understanding the effects of various factors on the oxidation of organic gases in the atmosphere and the formation of ozone and secondary particles.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2022)
Article
Environmental Sciences
Zhaomin Yang, Kun Li, Narcisse T. Tsona, Xin Luo, Lin Du
Summary: Our study investigates the effect of sulfur dioxide (SO2) on aerosol formation and composition. We found that the presence of SO2 leads to a significant increase in particle number concentration, mainly due to the formation of sulfuric acid (H2SO4) from the reactions between stabilized Criegee intermediates and SO2. Additionally, we observed the presence of organosulfates (OSs) which are likely formed through heterogeneous reactions between oxygenated species and H2SO4. These OSs have been previously identified in field studies but their sources and structures were unknown. We also found that the observed OSs are less volatile than their precursors and contribute to particle formation and growth in the presence of SO2.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2023)
Article
Environmental Sciences
Daniel J. Bryant, Beth S. Nelson, Stefan J. Swift, Sri Hapsari Budisulistiorini, Will S. Drysdale, Adam R. Vaughan, Mike J. Newland, James R. Hopkins, James M. Cash, Ben Langford, Eiko Nemitz, W. Joe F. Acton, C. Nicholas Hewitt, Tuhin Mandal, Bhola R. Gurjar, Shivani, Ranu Gadi, James D. Lee, Andrew R. Rickard, Jacqueline F. Hamilton
Summary: Delhi, India is one of the most polluted cities in the world, but little is known about the emissions of biogenic volatile organic compounds (VOCs) or the sources of secondary organic aerosol (SOA). This study provides the first molecular-level measurements of SOA derived from isoprene and monoterpene in Delhi, and demonstrates that both biogenic and anthropogenic sources of these compounds can be important in urban areas.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2023)
Article
Engineering, Environmental
Kelvin H. Bates, James D. Cope, Tran B. Nguyen
Summary: This study investigates the gas-phase reactions of 1,2-Dihydroxy isoprene (1,2-DHI) with OH radicals and ozone, finding rapid reactions and major products like hydroxyacetone, glycolaldehyde, and 2,3-dihydroxy-2-methyl-propanal (DHMP). Formation of radical-terminating hydroperoxide and organonitrate from RO2 reactions are not observed in gas phase due to low volatility, leading to branching ratios being derived by mass balance. Incorporating results into a global chemical transport model shows significant contributions of 1,2-DHI oxidation to atmospheric budgets of various compounds.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Engineering, Environmental
Congzi Xia, Cheng Liu, Zhaonan Cai, Xiaonan Duan, Qihou Hu, Fei Zhao, Haoran Liu, Xiangguang Ji, Chengxin Zhang, Yi Liu
Summary: Satellite measurements of sulfur dioxide (SO2) are widely used to estimate anthropogenic emissions, but the operational SO2 product of Sentinel-5 Precursor (S-5P) has been found to be overestimated compared to ground-based measurements in China and India. By improving the algorithm, the updated retrieval shows better agreement with ground-based measurements and reveals a significant decrease in SO2 emissions during the COVID-19 lockdown period.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Environmental Sciences
Wenyu Sun, Matias Berasategui, Andrea Pozzer, Jos Lelieveld, John N. Crowley
Summary: The OH-initiated oxidation of SO2 is the dominant first step in the transformation of this atmospherically important trace gas to particulate sulfate. This study addressed an important omission in the kinetic database for this reaction and highlighted significant discrepancies in recommended parameterizations. The presence of water vapor significantly enhances the rate coefficients of the reaction.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2022)
Article
Engineering, Environmental
Li Xu, Zhaomin Yang, Narcisse T. Tsona, Xinke Wang, Christian George, Lin Du
Summary: This study found that under dark conditions, the aerosol yield can be significantly enhanced by nitrogen dioxide or sulfur dioxide within a certain ratio range of inorganic gases to biogenic volatile organic compounds, while ammonia showed a slight increase. The nitrogen- and sulfur-containing aerosol components were derived from nitrogen dioxide, ammonia, and sulfur dioxide, with organic nitrates and organosulfates identified in the experiments. These interactions among various compounds during the night could serve as a potential pathway for the formation of particulate nitrogen- and sulfur-containing organics in polluted regions with both anthropogenic and biogenic influences.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Environmental Sciences
Nishesh Kumar Gupta, Jiyeol Bae, Soyoung Baek, Kwang Soo Kim
Summary: This study reported the fabrication of NaMxOy-type adsorbents from air calcination of (Na, M)-trimesate metal organic frameworks and tested their potential for low-temperature SO2 removal. The results showed that NMO and NCO adsorbents had good adsorption capacity for SO2 and the capacity increased with temperature, bed loading, and decreased flow rate. Elemental mapping and X-ray analysis confirmed the absence of metal sulfate nanoparticles in SO2-exposed samples and the formation of surface sulfate and bisulfate.
Article
Materials Science, Multidisciplinary
Nikesh Ingle, Pasha Sayyad, Megha Deshmukh, Gajanan Bodkhe, Manasi Mahadik, Theeazen Al-Gahouari, Sumedh Shirsat, Mahendra D. Shirsat
Summary: In this study, a flexible SO2 gas sensor was developed by modifying crystalline nickel(II)benzenetricarboxylate metal-organic framework (Ni-MOF) with activated single wall carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs). The introduction of -OH functionalized carbon nanotubes significantly improved the electrical and morphological properties of Ni-MOF, enhancing its sensing ability towards SO2 gas at room temperature. The composite exhibited efficient sensing characteristics with good selectivity and sensitivity towards SO2 gas.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Chemistry, Physical
Natalia Diaz Montenegro, William S. Epling
Summary: The methane oxidation and oxygen storage capacity of a bilayer Pt/Pd/Al2O3 over a Mn0.5Fe2.5O4 spinel catalyst under periodic conditions were studied before and after SO2 exposure. Improvement in CH4 oxidation conversion was observed under periodic conditions compared to steady-state conditions before sulfur exposure. After sulfur exposure, a loss in CH4 oxidation performance and oxygen storage capacity of the spinel material was observed, but regeneration methods under periodic conditions led to improved CH4 conversion.
APPLIED CATALYSIS B-ENVIRONMENTAL
(2023)
Article
Nanoscience & Nanotechnology
Dan Yang, Fang Dong, Weigao Han, Jiyi Zhang, Zhicheng Tang
Summary: The sulfur resistance of Pt/SiO2 catalyst was significantly improved by coating a metal oxide shell. Among them, the Pt/SiO2@MnOx catalyst coated with a MnOx shell showed the best performance. This is because the MnOx shell not only protected the Pt active site but also had a good electron transfer effect on the core Pt.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Environmental Sciences
Hailiang Zhang, Yongfu Xu, Long Jia
Summary: The catalytic oxidation of SO2 by metal ions in aerosol water, particularly Mn2+, is a significant source of sulfate in the atmospheric environment. Fe3+ has a lower reaction rate compared to Mn2+ in catalyzing the oxidation of SO2 in aerosol water. The synergistic catalysis between Fe3+ and Mn2+ for the oxidation of SO2 in aerosol water is limited.
ATMOSPHERIC ENVIRONMENT
(2021)
Article
Chemistry, Physical
Xiaolong Liu, Yang Zou, Xue Li, Tieyao Xu, Wanglai Cen, Bin Li, Tingyu Zhu
Summary: By introducing various dopants into Pt/Ti bimetallic catalysts, the efficiency and sulfur resistance of CO oxidation can be significantly improved. The introduction of appropriate dopants enhances the active oxygen supplying ability of the catalyst and improves the reaction activity. Experimental results show that the deposition of sulfur on the Pt-0.5Mn/Ti surface is minimal, and Pt-0.5Mn/Ti has weaker SO2 adsorption, which explains its stronger sulfur resistance.
Article
Energy & Fuels
Zahraa Dbouk, Nesrine Belhadj, Maxence Lailliau, Roland Benoit, Philippe Dagaut
Summary: In this study, limonene and alpha-pinene mixtures were oxidized under atmospheric pressure, at cool flame regime and fuel-lean conditions. Analysis of the reacting mixtures revealed numerous oxidation products including highly oxygenated organic compounds and aromatic, polyunsaturated products.
Article
Environmental Sciences
Benjamin de Foy, William H. Brune, James J. Schauer
ENVIRONMENTAL POLLUTION
(2020)
Article
Meteorology & Atmospheric Sciences
Siyuan Wang, Eric C. Apel, Rebecca H. Schwantes, Kelvin H. Bates, Daniel J. Jacob, Emily Fischer, Rebecca S. Hornbrook, Alan J. Hills, Louisa K. Emmons, Laura L. Pan, Shawn Honomichl, Simone Tilmes, Jean-Francois Lamarque, Mingxi Yang, Christa A. Marandino, Eric S. Saltzman, Warren de Bruyn, Sohiko Kameyama, Hiroshi Tanimoto, Yuko Omori, Samuel R. Hall, Kirk Ullmann, Thomas B. Ryerson, Chelsea R. Thompson, Jeff Peischl, Bruce C. Daube, Roisin Commane, Kathryn McKain, Colm Sweeney, Alexander B. Thames, David O. Miller, William H. Brune, Glenn S. Diskin, Joshua P. DiGangi, Steven C. Wofsy
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2020)
Article
Environmental Sciences
Miguel Zavala, William H. Brune, Erik Velasco, Armando Retama, Luis Adrian Cruz-Alavez, Luisa T. Molina
ATMOSPHERIC ENVIRONMENT
(2020)
Article
Microbiology
Piero Di Carlo, Katia Falasca, Claudio Ucciferri, Bruna Sinjari, Eleonora Aruffo, Ivana Antonucci, Alessandra Di Serafino, Arianna Pompilio, Verena Damiani, Domitilla Mandatori, Simone De Fabritiis, Beatrice Dufrusine, Emily Capone, Piero Chiacchiaretta, William H. Brune, Giovanni Di Bonaventura, Jacopo Vecchiet
Summary: This study found that even during normal breathing, viral RNA of SARS-CoV-2 could be detected in the air 1 cm around the mouths of patients with viral RNA in oropharyngeal and nasopharyngeal swabs, indicating that infection could potentially come from the breath of asymptomatic carriers.
JOURNAL OF MEDICAL MICROBIOLOGY
(2021)
Article
Multidisciplinary Sciences
W. H. Brune, P. J. McFarland, E. Bruning, S. Waugh, D. MacGorman, D. O. Miller, J. M. Jenkins, X. Ren, J. Mao, J. Peischl
Summary: Lightning enhances the atmosphere's self-cleansing ability by producing nitric oxide (NO) and forming ozone (O-3) and the oxidant hydroxyl radical (OH). It also directly generates the oxidants OH and the hydroperoxyl radical (HO2), with orders of magnitude greater quantities than previous atmospheric observations. Lightning-generated OH in all storms globally may account for a highly uncertain, but substantial, 2 to 16% of global atmospheric OH oxidation.
Article
Meteorology & Atmospheric Sciences
Jena M. Jenkins, William H. Brune, David O. Miller
Summary: This laboratory study demonstrates that prodigious amounts of HOx can be generated through electrical discharges over ranges of pressure and water vapor mixing ratios relevant to the troposphere. The results show that HOx and OH exposure were approximately independent of pressure and slightly increased with water vapor, while NOx was approximately independent of both pressure and water vapor.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2021)
Article
Environmental Sciences
William H. Brune, David O. Miller, Alexander B. Thames, Alexandra L. Brosius, Barbara Barletta, Donald R. Blake, Nicola J. Blake, Gao Chen, Yonghoon Choi, James H. Crawford, Joshua P. Digangi, Glenn Diskin, Alan Fried, Samuel R. Hall, Thomas F. Hanisco, Greg L. Huey, Stacey C. Hughes, Michelle Kim, Simone Meinardi, Denise D. Montzka, Sally E. Pusede, Jason R. Schroeder, Alex Teng, David J. Tanner, Kirk Ullmann, James Walega, Andrew Weinheimer, Armin Wisthaler, Paul O. Wennberg
Summary: South Korea frequently experiences poor air quality with ozone and small particles exceeding standards. The KORUS-AQ study collected measurements of various chemical species, including OH and HO2, in order to better understand this issue. The study found inconsistencies between model calculations and observations, likely due to instrument variability and difficulties in data interpolation. The missing OH reactivity primarily originates from the Korean peninsula.
ATMOSPHERIC ENVIRONMENT
(2022)
Article
Geosciences, Multidisciplinary
Jingqiu Mao, Tianlang Zhao, Christoph A. Keller, Xuan Wang, Patrick J. McFarland, Jena M. Jenkins, William H. Brune
Summary: Lightning plays a significant role in tropospheric oxidation by generating a large amount of oxidants, including HOx and O-3, which can impact global tropospheric composition, particularly affecting OH, CO, O-3, and reactive nitrogen. The study emphasizes the importance and uncertainties of lightning-produced oxidants, underscoring the need to reconsider the role of lightning in tropospheric oxidation chemistry.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Meteorology & Atmospheric Sciences
David O. Miller, William H. Brune
Summary: Understanding the chemistry of OH and HO2 in the atmosphere is crucial for studying the impact of human activity on atmospheric composition and climate. Comparing observed and modeled data from the Penn State Airborne Tropospheric Hydrogen Oxides Sensor (ATHOS), it was found that the oxidation chemistry in most of the free troposphere is well understood, but specific environments such as cities, forests, and pollution plumes can be influenced by the model's chemical mechanism and data set size.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2022)
Article
Meteorology & Atmospheric Sciences
J. M. Jenkins, G. A. Olson, P. J. McFarland, D. O. Miller, W. H. Brune
Summary: Prodigious amounts of hydroxyl radical (OH) are generated on tree leaves through corona discharges in the laboratory and during thunderstorms. The production rates depend on electric field, leaf dryness, and the presence of liquid water. Corona-generated OH may have significant impacts on atmospheric oxidation and tree and forest ecology.
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
(2022)
Article
Multidisciplinary Sciences
William H. Brune, Jena M. Jenkins, Gabrielle A. Olson, Patrick J. McFarland, David O. Miller, Jingqiu Mao, Xinrong Ren
Summary: Atmospheric electrical discharges, specifically corona formed on grounded metal objects under thunderstorms, generate significant amounts of OH, HO2, and O-3. Field measurements and laboratory experiments show that corona on lightning rods and high-voltage power lines can produce concentrations of OH that are significantly higher than ambient levels.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2022)
Article
Chemistry, Multidisciplinary
Anita M. Avery, Mitchell W. Alton, Manjula R. Canagaratna, Jordan E. Krechmer, Donna T. Sueper, Nirvan Bhattacharyya, Lea Hildebrandt Ruiz, William H. Brune, Andrew T. Lambe
Summary: Cyclic volatile methyl siloxanes (cVMS) emitted from industrial processes and consumer products dominate the presence of volatile organic compounds (VOCs) in occupied spaces. These cVMS can undergo oxidation by gas-phase radicals, such as hydroxyl radicals (OH) and chlorine atoms (Cl), leading to the formation of secondary organic aerosols (SOA). While the SOA formation potential of cVMS with OH has been studied, the impact of Cl oxidation on SOA formation has not been explored.
ACS EARTH AND SPACE CHEMISTRY
(2023)
Article
Environmental Sciences
Amir H. Souri, Matthew S. Johnson, Glenn M. Wolfe, James H. Crawford, Alan Fried, Armin Wisthaler, William H. Brune, Donald R. Blake, Andrew J. Weinheimer, Tijl Verhoelst, Steven Compernolle, Gaia Pinardi, Corinne Vigouroux, Bavo Langerock, Sungyeon Choi, Lok Lamsal, Lei Zhu, Shuai Sun, Ronald C. Cohen, Kyung-Eun Min, Changmin Cho, Sajeev Philip, Xiong Liu, Kelly Chance
Summary: The use of the ratio between formaldehyde (HCHO) and nitrogen dioxide (NO2) tropospheric columns from ultraviolet-visible (UV-Vis) satellites has been motivated by the availability of these data, allowing researchers to gain insights into near-surface ozone sensitivity.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2023)
Article
Chemistry, Physical
Saewung Kim, Roger Seco, Dasa Gu, Dianne Sanchez, Daun Jeong, Alex B. Guenther, Youngro Lee, John E. Mak, Luping Su, Dan Bi Kim, Youngjae Lee, Joon-Young Ahn, Tom Mcgee, John Sullivan, Russell Long, William H. Brune, Alexander Thames, Armin Wisthaler, Markus Mueller, Thomas Mikoviny, Andy Weinheimer, Melissa Yang, Jung-Hun Woo, Soyoung Kim, Hyunjoo Park
Summary: The study focuses on trace gas vertical profiles observed during the 2016 KORUS field campaign near the Seoul metropolitan area, emphasizing the importance of integrating ground and airborne observations.
FARADAY DISCUSSIONS
(2021)
Article
Environmental Sciences
Jake P. Rowe, Andrew T. Lambe, William H. Brune
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2020)
