Water-soluble brown carbon in PM2.5 at two typical sites in Guanzhong Basin: Optical properties, sources, and implications

Atmospheric Research, Journal Year: 2022, Volume and Issue: 281, P. 106499 - 106499

Published: Nov. 2, 2022

Brown carbon (BrC) is a light-absorbing aerosol component that has significant impact on atmospheric photochemistry and climate effects. Many studies light absorbing characteristics of BrC (such as fraction water-soluble and/or water-insoluble) have been carried out in cities over the Guanzhong Basin, including radiative forcing, optical properties sources. However, research Qinling Mountains still lacking. Therefore, PM2.5 samples were collected at northern piedmont (QL) Xi'an (XN) winter 2020, radiation effects water extracts analyzed evaluated. The mass absorption efficiency (MAE) organic (WSOC) 365 nm (MAE365) obtained QL XN 0.18 ± 0.03 m2 g−1 0.78 0.96 g−1, respectively. In ultraviolet range, relative WSOC to elemental (EC) was 6.76% 33.41% XN, respectively, simple forcing (SFE280–400) 0.71 0.43 2.82 1.71 W XN. It may important balance regional systems. chromophores are mainly composed humic-like protein-like substances, humus-like substances play dominant role two sites (52.61% 71.13%). Biomass combustion limited contribution chromophore abundance QL, which more affected by urban transmission. fluorescence index revealed had autogenous matter mostly newly generated. Furthermore, molecular weight aromatic degree higher than indicating greater capacity for absorption. This work will be instrumental assessing interaction influence between city improve capability air pollution prevention control Basin.

Language: Английский

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Optical properties of vehicular brown carbon emissions: Road tunnel and chassis dynamometer tests

Environmental Pollution, Journal Year: 2023, Volume and Issue: 320, P. 121037 - 121037

Published: Jan. 11, 2023

Language: Английский

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A Review on Brown Carbon Aerosol in China: From Molecular Composition to Climate Impact

Current Pollution Reports, Journal Year: 2024, Volume and Issue: 10(2), P. 326 - 343

Published: Feb. 29, 2024

Language: Английский

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Interannual evolution of the chemical composition, sources and processes of PM2.5 in Chengdu, China: Insights from observations in four winters

Journal of Environmental Sciences, Journal Year: 2023, Volume and Issue: 138, P. 32 - 45

Published: March 7, 2023

Language: Английский

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Variations in optical properties of water- and methanol-soluble organic carbon in PM2.5 in Tianjin and Handan over the Wintertime of 2018–2020

Atmospheric Research, Journal Year: 2024, Volume and Issue: 303, P. 107332 - 107332

Published: March 11, 2024

Language: Английский

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Seasonal characterization of chemical and optical properties of water-soluble organic aerosol in Beijing

The Science of The Total Environment, Journal Year: 2024, Volume and Issue: 930, P. 172508 - 172508

Published: April 18, 2024

Language: Английский

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Predictions of the Optical Properties of Brown Carbon Aerosol by Machine Learning with Typical Chromophores

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: 58(46), P. 20588 - 20597

Published: Nov. 7, 2024

The linkages between BrC optical properties and chemical composition remain inadequately understood, with quantified chromophores explaining less than 25% of ambient aerosol light absorption. This study characterized 38 typical in aerosols collected Xi'an, absorption contributions to ranging from 1.6 ± 0.3 5.8 2.6% at 365 nm. Based on these chromophores, an interpretable machine learning model the Shapley Additive Explanation (SHAP) method were employed explore relationships composition. attained high accuracy Pearson correlation coefficients (

Language: Английский

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Measurement report: Optical and structural properties of atmospheric water-soluble organic carbon in China – insights from multi-site spectroscopic measurements

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(6), P. 3647 - 3667

Published: March 27, 2025

Abstract. To understand the spatial variation of optical and structural properties water-soluble brown carbon its influencing factors in China, light absorption, fluorescence, Fourier transform infrared (FTIR) spectrum organic (WSOC) different regions China are measured following same analytical methods. The average absorption coefficients mass efficiencies WSOC at 365 nm (Abs365 MAE365) rank from high to low as northwest > southwest north east regional site, with higher values northern than southern sites inland areas coastal areas. resolved by spectra-based positive matrix factorization model abundance aromatic O−H C=C functional groups determined FTIR both indicate that compounds significant light-absorbing substances have a impact on fluorophores. Multiple linear regression analysis shows fluorophores identified fluorescence spectra combined parallel factor (PARAFAC) contribute about 62 %–93 % all sites, which humic-like substance (HULIS) contributes most, especially highly oxygenated HULIS (29 %–50 %) long emission wavelengths. Combustion source emissions atmospheric chemical processes impacts some sites. Moreover, relative humidity (RH) can also affect MAE365 WSOC, decreasing increase RH when RH<60 remaining relatively unchanged RH>60 %. Taken together, this study promotes better understanding heterogeneity their China.

Language: Английский

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Characterization and source apportionment of brown carbon via online measurements in a typical industrial-polluted city in eastern China

Environmental Research, Journal Year: 2025, Volume and Issue: 278, P. 121731 - 121731

Published: April 29, 2025

Language: Английский

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Different formation pathways of nitrogen-containing organic compounds in aerosols and fog water in northern China

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(12), P. 6987 - 6999

Published: June 18, 2024

Abstract. While aqueous-phase processing is known to contribute the formation of nitrogen-containing organic compounds (NOCs), specific pathways involved remain poorly understood. In this study, we aimed characterize NOCs present in both pre-fog aerosols and fog water collected at a suburban site northern China. Fourier-transform ion cyclotron resonance mass spectrometry was utilized analyze molecular composition negative positive modes electrospray ionization (ESI− ESI+). samples, constituted significant portion, accounting for over 60 % all assigned formulas ESI− more than 80 ESI+. By comparing originating from biomass burning, coal combustion, vehicle emissions, identified that 72.3 were attributed primary anthropogenic sources (pNOCs), while remaining categorized as secondary formed within (saNOCs). Unique found classified (sfNOCs). Through comprehensive “precursor–product pair” screening involving 39 reaction pathways, observed nitration reaction, amine pathway, intramolecular N-heterocycle pathway NH3 addition reactions contributed 43.6 %, 22.1 11.6 saNOCs, respectively. contrast, these 26.8 28.4 29.7 sfNOCs, This disparity likely influenced by diverse precursors, aqueous acidity, gas-phase species partitioning. Correspondingly, saNOCs contain higher abundance carbohydrate-like highly oxygenated with two nitrogen atoms compared pNOCs. Conversely, sfNOCs exhibited content lipid-like fewer oxygen atoms. These results underscore distinct processes contributing diversity water, which may lead their different climate effects.

Language: Английский

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