Aqueous-Phase Reactions of Anthropogenic Emissions Lead to the High Chemodiversity of Atmospheric Nitrogen-Containing Compounds during the Haze Event

Environmental Science & Technology, Год журнала: 2023, Номер 57(43), С. 16500 - 16511

Опубликована: Окт. 16, 2023

Nitrogen-containing organic compounds (NOCs), a type of important reactive-nitrogen species, are abundant in aerosols haze events observed Northern China. However, due to the complex nature NOCs, sources, formation, and influencing factors still ambiguous. Here, molecular composition matters (OMs) hourly PM2.5 samples collected during event China was characterized using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). We found that CHON (formulas containing C, H, O, N atoms) dominated OM fractions showed high chemodiversity transformability. Relying on newly developed revised-workflow oxidation-hydrolyzation knowledge for compounds, 64% major aromatic (>80%) could be derived from oxidization or hydrolyzation processes. Results FT-ICR MS data analysis further aerosol liquid water (ALW)-involved aqueous-phase reactions distribution aromatic-CHON besides coal combustion, ALW-involved compound formation daytime nighttime different. Our results improve understanding composition, potential which can help advance evolution, control haze.

Язык: Английский

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Insights into the transformation of natural organic matter during UV/peroxydisulfate treatment by FT-ICR MS and machine learning: Non-negligible formation of organosulfates

Water Research, Год журнала: 2024, Номер 256, С. 121564 - 121564

Опубликована: Апрель 1, 2024

Язык: Английский

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Enhancing Oxygen Activation Ability by Composite Interface Construction over a 2D Co₃O₄-Based Monolithic Catalyst for Toluene Oxidation

Environmental Science & Technology, Год журнала: 2024, Номер 58(33), С. 14906 - 14917

Опубликована: Авг. 6, 2024

Developing robust metal-based monolithic catalysts with efficient oxygen activation capacity is crucial for thermal catalytic treatment of volatile organic compound (VOC) pollution. Two-dimensional (2D) metal oxides are alternative catalysts, but their traditional loading strategies on carriers still face challenges in practical applications. Herein, we propose a novel situ molten salt-loading strategy that synchronously enables the construction 2D Co

Язык: Английский

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Nitroaromatic Compounds from Secondary Nitrate Formation and Biomass Burning Are Major Proinflammatory Components in Organic Aerosols in Guangzhou: A Bioassay Combining High-Resolution Mass Spectrometry Analysis

Environmental Science & Technology, Год журнала: 2023, Номер 57(51), С. 21570 - 21580

Опубликована: Ноя. 21, 2023

The limited characterization and detection capacity of unknown compounds hinder our understanding the molecular composition toxic in PM2.5. present study applied Fourier transform ion cyclotron resonance mass spectrometry coupled with negative positive electrospray ionization sources (ESI–/ESI+ FT-ICR-MS) to probe characteristics dynamic formation processes effective proinflammatory components organic aerosols (OAs) PM2.5 Guangzhou for one year. We detected abundant molecules OAs, mainly classified as CHON (compounds composed C, H, O, N atoms) elemental nitroaromatic (NACs) structures. From perspective process, we discovered that these molecules, especially NACs, were largely driven by secondary nitrate biomass burning (in emission source), well SO2 atmospheric evolution). In addition, results indicated had replaced primary main contributing source OAs. This highlights importance community measures control production derived from urban areas.

Язык: Английский

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Efficient photocatalytic NO removal with inhibited NO2 formation and catalyst loss over sponge-supported and functionalized g-C3N4

Journal of Hazardous Materials, Год журнала: 2023, Номер 465, С. 133323 - 133323

Опубликована: Дек. 20, 2023

Язык: Английский

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Applications of environmental mass spectrometry in atmospheric haze chemistry

TrAC Trends in Analytical Chemistry, Год журнала: 2024, Номер 172, С. 117614 - 117614

Опубликована: Фев. 21, 2024

Язык: Английский

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Predicted impacts of heterogeneous chemical pathways on particulate sulfur over Fairbanks (Alaska), the Northern Hemisphere, and the Contiguous United States

Atmospheric chemistry and physics, Год журнала: 2025, Номер 25(5), С. 3287 - 3312

Опубликована: Март 18, 2025

Abstract. A portion of Alaska's Fairbanks North Star Borough was designated as nonattainment for the 2006 24 h fine particulate matter 2.5 µm or less in diameter (PM2.5) National Ambient Air Quality Standards (NAAQS) 2009. PM2.5 NAAQS exceedances mainly occur during dark and cold winters, when temperature inversions form trap high emissions at surface. Sulfate (SO42-), often second-largest contributor to mass these wintertime PM episodes, is underpredicted by atmospheric chemical transport models (CTMs). Most CTMs account primary SO42- secondary formed via gas-phase oxidation sulfur dioxide (SO2) in-cloud aqueous dissolved S(IV). Dissolution reaction SO2 aerosols are generally not included but can be represented heterogeneous reactive uptake may help better represent concentrations observed winters. In addition, hydroxymethanesulfonate (HMS), a species sometimes misidentified SO42-, known Heterogeneous formation HMS aerosol liquid water (ALW) implemented Community Multiscale (CMAQ) modeling system. CMAQ simulations were performed episodes (2008) well over Northern Hemisphere Contiguous United States (CONUS) 2015–2016. The added chemistry reduced model mean sulfate bias ∼ 0.6 µg m−3 winter episode Fairbanks, AK. Improvements performance also seen Beijing haze events (reducing 2.9 S m−3). This additional improves modeled summertime southeastern US, with implications future biogenic organosulfates.

Язык: Английский

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Physicochemical Characterization of Air Pollution Particulate Matter (PM2.5 and PM>2.5) in an Urban Area of Cotonou, Benin

Atmosphere, Год журнала: 2023, Номер 14(2), С. 201 - 201

Опубликована: Янв. 18, 2023

PM2.5 and PM>2.5 samples were collected in Cotonou (Benin) using high volume cascade impaction air samplers. The samplings based on continuous collection over twelve days. Physical chemical characteristics of determined by size distribution (laser granulometry), specific surface areas (BET method), inorganic elements (ICP-MS), water-soluble ions (IC), CHNS analysis organic compounds (GC-MS). Average concentrations particulate matter 180.9 µg/m3 94.5 PM>2.5, respectively. higher recorded Ca2+,SO42−,NO3−, Na+ Cl− for both PM. Moreover, almost two-fold compared to with 10.7 total metals found versus 5.6 PM>2.5. Both PM under study presented similar repartition considering their percentages. Results suggested that contain agglomerates fine particles. Identification tools major pollution source as elements, paraffins, fatty acids ratios PAHs indicated originated from traffic exhaust.

Язык: Английский

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Impact of biogenic secondary organic aerosol (SOA) loading on the molecular composition of wintertime PM_2.5 in urban Tianjin: an insight from Fourier transform ion cyclotron resonance mass spectrometry

Atmospheric chemistry and physics, Год журнала: 2023, Номер 23(3), С. 2061 - 2077

Опубликована: Фев. 9, 2023

Abstract. Biomass burning is one of the key sources urban aerosols in North China Plain, especially during winter, when impact secondary organic (SOAs) formed from biogenic volatile compounds (BVOCs) generally considered to be minor. However, little known about influence SOA loading on molecular composition wintertime aerosols. Here, we investigated water-soluble fine particulate matter (PM2.5) Tianjin by ultrahigh-resolution Fourier transform ion cyclotron resonanc mass spectrometry (FT-ICR MS). Our results show that most CHO and CHON are derived biomass which poor oxygen contain aromatic rings probably contribute light-absorbing brown carbon (BrC) chromophores. Under moderate high SOA-loading conditions, nocturnal chemistry more efficient than photooxidation generate with content. low loading, content mainly photochemistry. Secondary oxidation monoterpenes. may productive sesquiterpene-derived compounds. In contrast, number- intensity-weight S-containing groups (CHOS CHONS) increased significantly increase agrees fact a majority identified as organosulfates (OSs) nitrooxy–organosulfates (nitrooxy–OSs) BVOCs. Terpenes potential major contributors nitrooxy–organosulfates. While beneficial formation under loading. The an important factor associated degree, nitrate group chemodiversity nitrooxy-organosulfates. Furthermore, our study suggests hydrolysis nitrooxy-organosulfates possible pathway for organosulfates.

Язык: Английский

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Bayesian inference-based estimation of hourly primary and secondary organic carbon in suburban Hong Kong: multi-temporal-scale variations and evolution characteristics during PM_2.5 episodes

Atmospheric chemistry and physics, Год журнала: 2024, Номер 24(10), С. 5803 - 5821

Опубликована: Май 22, 2024

Abstract. Observation-based data of primary and secondary organic carbon in ambient particulate matter (PM) are essential for model evaluation, climate air quality research, health effect assessments, mitigation policy development. Since there no direct measurement tools available to quantify (POC) (SOC) as separate quantities, their estimation relies on inference approaches using relevant measurable PM constituents. In this study, we measured hourly carbonaceous components major ions PM2.5 a year half suburban Hong Kong from July 2020 December 2021. We differentiated POC SOC novel Bayesian approach. The allowed us examine temporal characteristics varying diurnal weekly patterns seasonal variations, well evolution during individual episodes. A total 65 city-wide episodes were identified throughout the entire study period, with contributions 10 % 66 %. summertime typhoon episodes, elevated levels observed daytime hours, high temperature NOx significant factors contributing episodic formation. Winter haze exhibited levels, likely due persistent influences regional transport originating northern region sampling site. Enhanced formation was increase nocturnal NO3 radical (indicated by surrogate quantity [NO2][O3]) under conditions characterized water content strong acidity. These results suggest that both chemistry acid-catalyzed aqueous-phase reactions make notable winter methodology employed estimating provides practical guidance other locations similar monitoring capabilities place. availability is invaluable evaluating improving atmospheric models, understanding processes pollution This, turn, leads more accurate predictions better sources processes.

Язык: Английский

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