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Daytime Ozone Production Determined by Ratios of Total Volatile Organic Compound Consumption to Nitrogen Oxide Concentrations

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ACS ES&T Air

ACS ES&T Air 2025年第3期2卷 331-342页

作者： Xudong Zheng Qinwen Tan Jie Ren Bin Luo Danlin Song Miao Feng Hefan Liu Yue Qin Yufang Hao Liming Zeng Xin Li Sihua Lu Huabin Dong Shaodong Xie College of Environmental Sciences and Engineering State Key Joint Laboratory of Environmental Simulation and Pollution Control Peking University Beijing 100871 China Chengdu Academy of Environmental Sciences Chengdu Sichuan 610072 China Sichuan Academy of Environmental Policy and Planning Chengdu Sichuan 610041 China College of Environmental Sciences and Engineering State Key Joint Laboratory of Environmental Simulation and Pollution Control Peking University Beijing 100871 China；Laboratory of Atmospheric Chemistry Energy and Environment Research Division Paul Scherrer Institute Villigen 5232 Switzerland

To reduce the uncertainty in analyzing ozone (O3) sensitivities based on observed concentrations of volatile organic compounds (VOCs) and nitrogen dioxide, this study proposed the application of consumed VOC concentrations to establish their nonlinear relationship in the actual atmosphere. These parameters were calculated based on the reaction rates and online observations of VOCs, nitrogen dioxide, and O3concentrations at Deyang, Chengdu, and Meishan in the Chengdu Plain, China, during summer 2019. The nighttime isoprene consumption was maximum at 2.03 ppbv at Meishan. The daytime acetaldehyde consumption was a maximum at 2.68 ppbv at Deyang, possibly due to its higher primary emissions and secondary production and its consumption by both OH radicals and photolysis. When the ratios of the total consumed VOC concentrations to the observed or initial NOx(NOx= NO + NO2) concentrations were 3.51 ppbv ppbv–1or 2.22 ppbv ppbv–1, daytime O3variations reached a maximum of 8.45 ppbv or 7.52 ppbv, respectively. The ratios delineated the VOC-sensitive and NOx-sensitive areas. Over 98% of hourly data were in VOC-sensitive areas at both Chengdu and Meishan, respectively, while over 14% of hourly data belonged to NOx-sensitive areas at Deyang. This provided a more accurate method for assessing real-time O3sensitivity and thus implementing dynamic hierarchical control strategies.

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Bulk Quantification and Molecular Characterization of Thermal Decomposition from the Thermal Desorption of Organic Aerosol

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ACS ES&T Air

ACS ES&T Air 2024年第7期1卷 628-636页

作者： Qingfeng Guo Wei Hu Min Hu Yujue Wang Song Guo Zhijun Wu Jing Zheng Limin Zeng State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering International Joint Laboratory for Regional Pollution Control Ministry of Education (IJRC) Peking University Beijing 100871 China Institute of Surface-Earth System Science School of Earth System Science Tianjin University Tianjin 300072 China Collaborative Innovation Center of Atmospheric Environment and Equipment Technology Nanjing University of Information Science & Technology Nanjing 210044 China Key Laboratory of Marine Environment and Ecology Ministry of Education of China Ocean University of China Qingdao 266100 China

The thermal desorption (TD) technique has been widely employed to measure the molecular composition and volatility of organic aerosols through coupling to mass spectrometry. Although the impact of thermal decomposition on TD instruments has been discussed in the literature, its extent has not yet been quantified. Here, we quantify the decomposition of organic aerosol at the bulk level and qualitatively distinguish between compounds evaporating and decomposing at the molecular level through the combination of online thermodenuder aerosol mass spectrometer (TD-AMS), offline organic carbon/elemental carbon (OC/EC) analyzer, and ultra-high resolution mass spectrometer. Results show that up to 56% of organic mass in ambient aerosol decomposes at a desorption temperature lower than 180 °C, which means that large amounts of organics cannot be detected by TD-coupled instruments. Sulfur-containing compounds with larger molecular masses exhibit weaker thermal stability, making them more susceptible to thermal decomposition than other compounds not containing sulfur. This work provides a means to obtain quantitative and qualitative insights into the thermal decomposition of organic aerosol, which will aid in understanding secondary organic aerosol (SOA) formation and reducing the gap between SOA measurements and model simulations.

关键词： Aerosols Desorption Organic compounds Organic reactions Thermodynamic properties

Oxidation of Toluene Over the Mesoporous Mno2/Ceo2 Nanosphere Catalysts: Effects of the Mno2 Precursor and the Type of the Support

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SSRN 2023年

作者： Cui, Yan Zhang, Yixin Xu, Leilei Wu, Cai-E Zou, Weixin Zhang, Lan Wang, Ning Dong, Lin Hu, Xun Chen, Mindong Collaborative Innovation Centre of the Atmospheric Environment and Equipment Technology School of Environmental Science and Engineering Nanjing University of Information Science & Technology Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Nanjing210044 China College of Light Industry and Food Engineering Nanjing Forestry University Nanjing210037 China State Key Laboratory of Pollution Control and Resource Reuse School of the Environment Nanjing University Nanjing210093 China Faculty of Environment and Life Beijing University of Technology Beijing100124 China School of Material Science and Engineering University of Jinan Jinan250022 China

Toluene was the most common volatile organic compounds (VOCs), and MnO2-based catalysts was one of the excellent non-precious metal catalysts for the toluene oxidation. In this study, the effects of the MnO2 precursors and types of the supports on the catalytic oxidation activity of toluene were systematically explored. The results showed that the 15MnO2/MS-CeO2-N catalyst with Mn(NO3)2·4H2O as the precursor and the mesoporous CeO2 nanosphere (MS-CeO2) as the support exhibited the most excellent performance. To reveal the essential reason hidden behind, the calcination process of the catalyst precursor and the reaction process of the toluene oxidation were investigated by the in-situ DRIFTS. It was found that the MnO2 precursor and the type of the catalyst support could greatly influence the reaction intermediates and pathway. Therefore, the roles of the MnO2 precursor and type of the support should be the key considerations when developing the high-performance MnO2-based toluene oxidation catalysts. © 2023, The Authors. All rights reserved.

关键词： Cerium oxide

Driving Factors of Aerosol Ph Changes in Four Cities in Northern China During the 2022 Winter Olympics

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SSRN 2024年

作者： Zhu, Hongji Zhang, Xiang Liu, Yafei Chen, Jing Liu, Lianyou Hou, Dongli Liu, Xingang Yang, Yuanle Jiang, Jiongjiong State Key Joint Laboratory of Environmental Simulation & Pollution Control School of Environment Beijing Normal University Beijing100875 China Ecology Environment Monitoring Center of Hebei Province Shijiazhuang050000 China Jining Ecological Environment Affairs Center Jining272000 China Jining Ecological Environment Monitoring Center Jining272100 China Key Laboratory of Environmental Change and Natural Disaster Ministry of Education Beijing Normal University Beijing100875 China

Aerosol acidity (pH) plays a key factor in regulating aerosol composition;therefore, understanding the driving factors of aerosol pH is critical. In this study, the characteristics and driving factors of aerosol pH changes during different control periods during the 2022 Winter Olympics in four cities (Zhangjiakou, Baoding, Shijiazhuang, and Handan) in northern China, which were calculated via the ISORROPIA model, were studied on the basis of the observed air pollutants. The factors influencing the gas‒aerosol distribution of aerosol semivolatile components were explored. During the Winter Olympics, the aerosol pH in the four cities was between 2.75 and 4.66, which was weakly acidic. The aerosol pH in the four cities mostly peaked during the light-control period. control measures had a substantial effect on the concentration of gaseous precursors, and changes in sulfate, nitrate, and ammonium were the dominant driving factors for changes in aerosol pH during different periods. Ca2+ caused by dust was an important driving factor for the change in aerosol pH in Baoding. In the four cities, the temperature increased about 9°C from the strict-control period to the light-control period, and relative humidity increased about 15% from the light-control period to the noncontrol period. Therefore, temperature and relative humidity are also crucial driving factors of changes in aerosol pH. The pH, temperature, and aerosol liquid water content play important roles in the gas‒aerosol distribution of semivolatile components. This research can further elucidate the relationships among aerosol composition, aerosol pH, and meteorological factors, providing a scientific basis for formulating more effective aerosol control strategies. © 2024, The Authors. All rights reserved.

关键词： pH effects

2d Coordination Polymers Based on the Interaction between CucurbitUril and Light Lanthanide Metal Ions in the Presence of Copper Salts, and Use for the Detection of Nitrogenous Bases

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SSRN 2023年

作者： Chen, Kai Li, Jie Zhang, Ming-Hui Zhu, Zhao-Qiang Huang, Lin Redshaw, Carl Collaborative Innovation Center of Atmospheric Environment and Equipment Technology Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control School of Environmental Science and Engineering Nanjing University of Information Science & Technology Nanjing210044 China Chemistry School of Natural Sciences University of Hull HullHU6 7RX United Kingdom

The coordination of cucurbit[5]uril (Q[5]) with lanthanide cations (Ln3+), in the presence of Cu2+ cations, led to the formation of 2D-network coordination polymers, which have been investigated using single crystal X-ray diffraction. Experimental results revealed that crystals were only readily affordable for the systems involving the lighter lanthanide cations (La3+, Ce3+, Pr3+, Sm3+, Eu3+ and Tb3+), with all six Ln3+-Q[5] complexes (1 ~ 6) exhibiting similar coordination mode at the cucurbit[5]uril (Q[5]), and forming 2D-network coordination polymers with a 2D supramolecular assembly. One complex was found to detect Adenine (A) and Uracil (U) with high selectively. © 2023, The Authors. All rights reserved.

关键词： Copper

Deciphering the Anammox Microbial Community Succession with Humic Acid Exposure: Optimizing Large Anammox Granules for Robust Nitrogen Removal

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SSRN 2024年

作者： Liu, Changqing Yu, Jianghua Zhu, Xinxin Shi, Haoqian Wang, Xin Sun, Dongxiao Dong, Zhiqiang Zhu, Yijing Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control School of Environmental Science and Engineering Nanjing University of Information Science and Technology Nanjing210044 China China Railway Shanghai Engineering Group Municipal Environmental Protection Co. Ltd Shanghai201906 China College of Environmental Science and Engineering Tongji University Shanghai200092 China

The robustness of the anaerobic ammonia oxidation (anammox) process in treating wastewater with high concentrations of humic acids (HAs), including landfill leachate and sludge anaerobic digestion, has been paid great attention. This study revealed that the anammox sludge granule size of 1.0–2.0 mm could be robust under the HA exposure with high concentrations. The total nitrogen removal efficiency (NRE) was higher than 96.16% at the HA concentration of 20–100 mg/L, while reduced by 7.68% at the HA concentration of 500 mg/L. The increased extracellular polymeric substances (EPS) content which was stimulated by the HA exposure favored the formation of large granules (1.0–2.0 mm) by enveloping medium and micro granules (0.2–1.0 mm). The abundance of anammox bacteria Candidatus Brocadia was found to be higher (14.2%) in large anammox granules with the size of 1.0–2.0 mm, suggesting a potentially high anammox activity. However, the abundance of denitrifiers Denitratisoma increased by 4.3% in ultra-large anammox granules with the size of > 2.0 mm, which could be attributed to the high EPS content for heterotrophic denitrifiers metabolism as organic matter. The feedback mechanism of the anammox community for maintaining the ecological function under the HA exposure resulted in a closely related microbial community, with the correlations increased by 64.3%. This study revealed that the HA exposure of the anammox system resulted in the anammox granules of 1.0–2.0 mm size being the dominant granules with robust nitrogen removal, providing significant guidance for the optimization of anammox granules for an efficient treatment of HA-containing wastewater in anammox applications. © 2024, The Authors. All rights reserved.

关键词： Nitrogen removal

2D Coordination Polymers Based on the Interaction between CucurbitUril and Light Lanthanide Metal Ions in the Presence of Copper Salts, and Use for the Detection of Nitrogenous Bases

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SSRN 2023年

关键词： Copper

Impact of Anthropogenic and Natural Constituents on Particulate Matter in Oases Cities on the Southern Margin of the Taklimakan Desert Based on Merra-2 and Multi-Site Ground Observation

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SSRN 2024年

作者： Yu, Hao Wang, Jing Geng, Chunmei Yang, Wen Wang, Xinhua Yin, Baohui Gu, Chao Gao, Shuang Chen, Li Bai, Zhipeng State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental Sciences Beijing100012 China Key Laboratory of Yellow River and Huai River Water Environment and Pollution Control Ministry of Education Henan Key Laboratory for Environmental Pollution Control School of Environment Henan Normal University Henan Xinxiang453007 China The Xinjiang Uygur Autonomous Region environmental monitoring station Xinjiang Urumchi830011 China School of Geographic and Environmental Sciences Tianjin Normal University Tianjin300387 China

Dust is one of the main source of atmospheric particulate matter (PM). The impact of natural and anthropogenic activities on the source of dust has complicated the estimation of the contribution of natural dust to atmospheric PM. Therefore, determining the role of natural dust in PM is currently an important scientific challenge. In order to investigate the impact of dust on PM, we collected 300 PM filter-samples across five oasis cities on the southern edge of the Taklimakan Desert in 2016. Further, the Modern-Era Retrospective analysis for Research and Applications, version 2 (MERRA-2) data was used to quantify the contribution of natural dust to PM on sand dust and non-sand dust days. On sand dust days, CaSO4 and Na2SO4 were directly emitted from surface dust, leading to higher sulfate concentrations in PM. In contrast, the SO42- concentration was significantly affected by anthropogenic activities on non-sand dust days. Further, the particle size distribution of mineral dust in Taklimakan dust aerosols was relatively stable. The increase in the proportions of organic carbon - OC1 and OC2 was attributed to the mixed anthropogenic pollution during sand dust days, while automotive composite emissions and coal combustion were the main sources of elemental carbon - EC1 on non-sand dust days. Based on the results of MERRA-2 reanalysis data, natural dust constituted 53% and 70% of the total PM2.5 and PM10, respectively, on sand dust days. Our study elucidated the impact of dust on PM by measuring the contribution of natural dust under different weather conditions and identifying potential sources of PM in oasis cities. This study provides theoretical support for PM prevention and assessment of natural dust in oasis cities. © 2024, The Authors. All rights reserved.

关键词： Particle size

Aerosol in global oceanic regions: Four-decade trends, spatial patterns, and policy implications

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Science of the Total environment 2024年 947卷 174176页

作者： Li, Linxuan Wang, Xuehan Bi, Xiaohui Dai, Qili Liu, Baoshuang Wu, Jianhui Zhang, Yufen Feng, Yinchang State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control College of Environmental Science and Engineering Nankai University Tianjin300350 China Cooperative Laboratory for Atmospheric Environment-Health Research College of Environmental Science and Engineering Nankai University Tianjin300350 China

High aerosol loadings are observed not only in megacities on continents but also in oceanic regions like the Bohai Sea. This work provides a comprehensive analysis of the spatial and temporal variations in Aerosol Optical Depth (AOD) across different ocean regions worldwide over the past four decades, using remote sensing reanalysis data. The mean AOD value across all oceanic grids is approximately 0.112, with higher levels recorded in the Central Atlantic (~0.206), followed by the North Indian Ocean (~0.201), and the Western North Pacific (~0.197). A latitudinal analysis reveals that high AOD values are predominantly found in the Northern Hemisphere's oceanic regions, especially between latitudes 0° and 70° N. Except for the Gulf of California and Hudson Bay, AOD values in the other fourteen surveyed inland seas surpass the mean levels found at similar latitudes in oceanic regions. Among which, the Bohai Sea stands out as the most polluted oceanic region with AOD value of 0.35. Over the last four decades, AOD trends have revealed a significant decrease across about 89.5 % of global oceanic grids, while an increase in AOD is observed in low-latitude oceanic areas (30° S–30° N). Investigation into inland seas shows that nearly two-thirds have experienced a declining AOD trend, while sharply upward trends in AOD are primarily found in Asia. The Bohai Sea shows the largest increase in AOD, with an annual growth rate of 1.4 %. The turning-points of the AOD in each inland sea confirm the success of regional emission control policies initiated on the adjacent continents. To improve air quality in inland seas like the Bohai Sea, adjusting industrial layouts, such as relocating heavy industries from the surrounding coastal cities' proximities to areas near open seas, could significantly benefit public health. © 2024

关键词： Emission control