Gas-to-Aerosol Phase Partitioning of Atmospheric Water-Soluble Organic Compounds at a Rural Site in China: An Enhancing Effect of NH₃ on SOA Formation

Environmental Science & Technology, Journal Year: 2022, Volume and Issue: 56(7), P. 3915 - 3924

Published: March 17, 2022

Partitioning gaseous water-soluble organic compounds (WSOC) to the aerosol phase is a major formation pathway of atmospheric secondary aerosols (SOA). However, fundamental mechanism WSOC-partitioning process remains elusive. By simultaneous measurements both gas-phase WSOC (WSOCg) and aerosol-phase (WSOCp) formic acetic acids at rural site in Yangtze River Delta (YRD) region China during winter 2019, we showed that WSOCg campaign dominantly partitioned dry period (relative humidity (RH) < 80%) but liquid water (ALW) humid (RH > 80%), suggesting two distinct SOA processes region. In period, temperature was driving factor for uptake WSOCg. contrast, factors controlling absorption were ALW content pH, which significantly elevated by NH3 through NH4NO3 neutralization with acids. Additionally, found relative abundances WSOCp strong linear correlation throughout spatial distribution consistent NH3, further indicating key role national scale. Since constitutes part SOA, such promoting effect on production elevating partitioning suggests emission control necessary mitigating haze pollution, especially China.

Language: Английский

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Nitrogen-Containing Compounds Enhance Light Absorption of Aromatic-Derived Brown Carbon

Environmental Science & Technology, Journal Year: 2022, Volume and Issue: 56(7), P. 4005 - 4016

Published: Feb. 22, 2022

The formation of secondary brown carbon (BrC) is chemically complex, leading to an unclear relationship between its molecular composition and optical properties. Here, we present in-depth investigation molecular-specific properties aging BrC produced from the photooxidation ethylbenzene at varied NOx levels for first time. Due pronounced unsaturated products, mass absorption coefficient (MAC) organic aerosols (ESOA) 365 nm was higher than that biogenic SOA by a factor 10. A high level ([ethylbenzene]0/[NOx]0 < 10 ppbC ppb–1) found significantly increase average MAC300–700nm ESOA 0.29 m2 g–1. data two complementary high-resolution spectrometers quantum chemical calculations suggested nitrogen-containing compounds were largely responsible enhanced light high-NOx ESOA, multifunctional nitroaromatic (such as C8H9NO3 C8H9NO4) identified important chromophores. High-NOx underwent photobleaching upon direct exposure ultraviolet light. Photolysis did not lead significant decomposition C8H9NO4, indicating may serve relatively stable nitrogen reservoirs would effectively absorb solar radiation during daytime.

Language: Английский

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Significant coal combustion contribution to water-soluble brown carbon during winter in Xingtai, China: Optical properties and sources

Journal of Environmental Sciences, Journal Year: 2022, Volume and Issue: 124, P. 892 - 900

Published: Feb. 26, 2022

Language: Английский

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Measurement report: Effects of anthropogenic emissions and environmental factors on the formation of biogenic secondary organic aerosol (BSOA) in a coastal city of southeastern China

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(11), P. 7827 - 7841

Published: June 16, 2022

Abstract. To better understand the formation of biogenic secondary organic aerosol (BSOA), samples with a 4 h time resolution were collected during summer and winter in southeast China, along online measurements trace gases, chemical compositions, meteorological parameters. The analyzed by gas chromatography–mass spectrometry for PM2.5-bound (SOA) tracers, including isoprene (SOAI), α/β-pinene (SOAM), β-caryophyllene (SOAC), toluene (ASOA). average concentrations total SOA tracers 38.8 111.9 ng m−3, respectively, predominance SOAM (70.1 % 45.8 %), followed SOAI (14.0 45.6 ASOA (11.0 6.2 %) SOAC (4.9 2.3 %). Compared to those winter, majority BSOA showed significant positive correlations Ox (O3+NO2) (r = 0.443–0.808), HONO 0.299–0.601), ultraviolet (UV) 0.382–0.588) temperature (T) 0.529–0.852), indicating influence photochemical oxidation under relatively clean conditions. However, significantly correlated PM2.5 0.407–0.867), NO3- 0.416–0.884), SO42- 0.419–0.813), NH3 0.440–0.757), attributed contributions anthropogenic emissions. Major both seasons linearly acidity (pH) 0.421–0.752), liquid water content (LWC) 0.403–0.876) 0.419–0.813). results indicated that acid-catalyzed reactive uptake onto sulfate particles enhanced BSOA. In summer, air mass originated from ocean, chlorine depletion was observed. We also found HCl (R2=0.545) ions 0.280–0.639) PM2.5, reflecting contribution Cl-initiated volatile compound (VOC) oxidations SOA. northeast dominant wind direction brought continental polluted monitoring site, affecting transformation tracers. This implied emissions, atmospheric capacity halogen chemistry have effects on coastal area.

Language: Английский

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Molecular analysis of secondary organic aerosol and brown carbon from the oxidation of indole

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(4), P. 2639 - 2649

Published: Feb. 29, 2024

Abstract. Indole (ind) is a nitrogen-containing heterocyclic volatile organic compound commonly emitted from animal husbandry and different plants like maize with global emissions of 0.1 Tg yr−1. The chemical composition optical properties indole secondary aerosol (SOA) brown carbon (BrC) are still not well understood. To address this, environmental chamber experiments were conducted to investigate the oxidation at atmospherically relevant concentrations selected oxidants (OH radicals O3) or without NO2. In presence NO2, SOA yields decreased by more than factor 2, but mass absorption coefficient 365 nm (MAC365) ind-SOA was 4.3 ± 0.4 m2 g−1, which 5 times higher that in C8H6N2O2 (identified as 3-nitroindole) contributed 76 % all compounds detected ionization spectrometer, contributing ∼ 50 light (Abs365). absence dominating chromophore C8H7O3N, 20 %–30 Abs365. contributes substantially formation BrC its potential impact on atmospheric radiative transfer further enhanced it significantly increases specific facilitating 3-nitroindole. This work provides new insights into an important process interaction two pollutants, NO2 indole, mainly anthropogenic activities.

Language: Английский

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Smog chamber study on the NOx dependence of SOA from isoprene photo-oxidation: implication on RO2 chemistry

Journal of Environmental Sciences, Journal Year: 2025, Volume and Issue: unknown

Published: May 1, 2025

Language: Английский

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Investigation into the differences and relationships between gasSOA and aqSOA in winter haze pollution on Chongming Island, Shanghai, based on VOCs observation

Environmental Pollution, Journal Year: 2022, Volume and Issue: 316, P. 120684 - 120684

Published: Nov. 16, 2022

Language: Английский

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Formation of secondary aerosol from emissions of a Euro 6d-compliant gasoline vehicle with particle filter

Environmental Science Atmospheres, Journal Year: 2024, Volume and Issue: 4(7), P. 802 - 812

Published: Jan. 1, 2024

The exhaust of a Euro 6d compliant car with three-way catalyst and GPF preinstalled was studied. removed almost all primary particles, however oxidation emitted VOCs such as toluene xylene led to significant SOA formation.

Language: Английский

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Effects of NO2 and RH on secondary organic aerosol formation and light absorption from OH oxidation of ο-xylene

Chemosphere, Journal Year: 2022, Volume and Issue: 308, P. 136541 - 136541

Published: Sept. 20, 2022

Language: Английский

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Continuous Measurement and Molecular Compositions of Atmospheric Water‐Soluble Brown Carbon in the Nearshore Marine Boundary Layer of Northern China: Secondary Formation and Influencing Factors

Journal of Geophysical Research Atmospheres, Journal Year: 2023, Volume and Issue: 128(12)

Published: June 12, 2023

Abstract Understanding the evolution of brown carbon (BrC) in atmosphere is essential for investigating its climate effects. This study deployed a novel in‐situ BrC continuous observation system to firstly measure water‐soluble absorption (Abs WS‐BrC ) an offshore island over Bohai Sea winter 2020. The Abs abundance before cold wave (BCW) was more than twice higher that after (ACW). mainly ascribed substantially suppressed formation secondary (WS‐BrC sec ). Diurnal patterns exhibited nighttime peaks, which derived from enhanced primary emissions and strong aqueous‐phase processes. Photochemical processes bleached daytime during BCW, while peaks emerged ACW due weakened photobleaching effect. Statistical analysis indicated ambient temperature relative humidity as well total oxidized nitrogen (NO 2 + NO 3 − reduced (NH 4 NH were dominant factors promoting . Moderate aerosol pH (>2.5) also facilitated no obvious dependences on gas‐particle partitioning ammonia, O , sulfur precursors found. At molecular level, chromophores with identified compositions, oxidation state, O/C, H/C, spectra compared between two periods. Characteristics CHO‐ CHON‐BrC origin contributed significantly ACW. highlights advantage high resolution measurement probing dynamic influencing factors.

Language: Английский

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