Molecular insights into the composition, sources, and aging of atmospheric brown carbon

Chemical Society Reviews, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

The light-absorbing chemical components of atmospheric organic aerosols are commonly referred to as Brown Carbon (BrC), reflecting the characteristic yellowish brown appearance aerosol.

Language: Английский

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Molecular Insights into Gas–Particle Partitioning and Viscosity of Atmospheric Brown Carbon

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 4, 2024

Biomass burning organic aerosol (BBOA), containing brown carbon chromophores, plays a critical role in atmospheric chemistry and climate forcing. However, the effects of evaporation on BBOA volatility viscosity under different environmental conditions remain poorly understood. This study focuses molecular characterization laboratory-generated proxies from wood pyrolysis emissions. The initial mixture, "pyrolysis oil (PO

Language: Английский

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Enhanced sulfate formation in mixed biomass burning and sea-salt interactions mediated by photosensitization: effects of chloride, nitrogen-containing compounds, and atmospheric aging

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(1), P. 425 - 439

Published: Jan. 13, 2025

Abstract. Discrepancies persist between modeled simulations and measured sulfate concentrations in the marine boundary layer, especially when air is influenced by biomass burning plumes. However, there has been a notable dearth of research conducted on interactions sea-salt aerosol plumes, impeding comprehensive understanding formation. This work studied formation mixing real (BB) extracts NaCl, mimicking internal mixtures BB particles. BB–NaCl particles had significantly higher rate than incense (IS)–NaCl For fresh particles, followed trend corn straw (CS)–NaCl > rice (RS)–NaCl wheat (WS)–NaCl IS–NaCl. The filter sample aging was achieved exposure to OH• generated from UV irradiation. After aging, RS–NaCl exhibited highest enhancement rates among all due RS NaCl. Bulk aqueous experiments spiked with NaCl using model photosensitizers (PSs) nitrogen-containing organic compounds (NOCs), pyrazine (CHN), 4-nitrocatechol (CHON) revealed positive effects chloride PS–CHON system negative PS–CHN Our suggests that reaching or near coastal areas can affect via photosensitizer-mediated reactions, potentially exacerbating pollution.

Language: Английский

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Increased UV–Visible Particle Absorption via Evaporation and Drying of Aqueous Droplets Containing Catechol/HONO Solutions

Environmental Science & Technology Letters, Journal Year: 2025, Volume and Issue: unknown

Published: April 29, 2025

Language: Английский

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Multiphase Processing of the Water-Soluble and Insoluble Phases of Biomass Burning Organic Aerosol

ACS ES&T Air, Journal Year: 2025, Volume and Issue: unknown

Published: March 31, 2025

Biomass burning is one of the most significant sources organic aerosol in atmosphere. (BBOA) has been observed to undergo liquid–liquid phase separation (LLPS) give core–shell morphology with hydrophobic encapsulating hydrophilic phase, potentially impacting evolution light-absorbing components, i.e., brown carbon (BrC), through multiphase processes. Here, we demonstrate how processing differs between water-soluble (i.e., hydrophilic) and insoluble hydrophobic) phases BBOA terms reactive uptake ozone a coated-wall flow tube. Effects relative humidity (RH) ultraviolet (UV) irradiation were investigated. Experimental timeseries used inform simulations using multilayer kinetic modeling. Among non-irradiated thin films, coefficient was greatest for at 75% RH (3 × 10–5, corresponding diffusion BrC, DBrC, 3 10–9 cm2 s–1) least same 0% (1 DBrC 1 10–10 s–1). The water-insoluble fell these two (about 1.5 10–5), regardless RH, increased only slightly (8 s–1 9 RH). coefficients both decreased significantly after UV irradiation, consistent transition from viscous liquid solid supported by qualitative microscopy observations. Modeling oxidation primary BrC components atmosphere demonstrated, first, that LLPS may extend lifetime encapsulated species factor moderate high and, also, more than 2.5.

Language: Английский

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Changes in Light Absorption and Chemical Properties for Biomass Burning Organic Aerosol over Long Time Scales

ACS ES&T Air, Journal Year: 2025, Volume and Issue: unknown

Published: April 7, 2025

Language: Английский

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Molecular Characterization and Photoreactivity of Organic Aerosols Formed from Pyrolysis of Urban Materials during Fires at the Wildland–Urban Interface

ACS ES&T Air, Journal Year: 2024, Volume and Issue: 1(11), P. 1495 - 1506

Published: Oct. 17, 2024

Fires at the wildland-urban interface (WUI) are increasing in magnitude and frequency, emitting organic aerosol (OA) with unknown composition atmospheric impacts. In this study, we investigated chemical of OA produced through 600 °C pyrolysis ten urban materials nitrogen, which were subsequently aged under UV light for 2 h. The analysis utilized ultrahigh-performance liquid chromatography (UHPLC) separation, coupled a photodiode array (PDA) detector high-resolution mass spectrometer (HRMS) molecular characterization. Hierarchical clustering demonstrated that lumber-derived was most diverse distinct composition. Unaged (for each material) did not significantly differ identities. Potential aromatic brown carbon (BrC) chromophores (based on their degree unsaturation) constituted 13-42% all assigned compounds. PDA chromatograms revealed multiple BrC chromophoric species either enhanced or degraded as result aging, providing insights into specific responsible photobleaching photoenhancement overall absorption coefficient. Thirty-six identified across types, structures confirmed using reference standards. Components plasticizers resins, such phthalic terephthalic acids, structurally samples. We present potential WUI fires components epoxies, dyes, adhesives commonly used manufacturing materials. Photolysis impact emitted from burning

Language: Английский

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Brown Carbon in East Asia: Seasonality, Sources, and Influences on Regional Climate and Air Quality

ACS Environmental Au, Journal Year: 2024, Volume and Issue: 5(1), P. 128 - 137

Published: Nov. 13, 2024

Brown carbon (BrC) has been recognized as an important light-absorbing carbonaceous aerosol, yet understanding of its influence on regional climate and air quality lacking, mainly due to the ignorance coupled meteorology-chemistry models. Besides, assumptions about emissions in previous explorations might cause large uncertainties estimates. Here, we implemented a BrC module into WRF-Chem model that considers source-dependent absorption avoids caused by emission intensities. To our best knowledge, made first effort consider model. We then applied developed explore impacts radiative forcing, climate, East Asia. found notable increases aerosol optical depth (AAOD) areas with high OC concentrations. The most intense forcing occurs autumn over Southeast Asia, values could reach around 4 W m-2. intensified atmospheric modified surface energy balance, resulting subsequent declines temperature, heat flux, boundary layer height, turbulence exchanging rates. These changes meteorological variables additionally near-surface dispersion photochemical conditions, leading PM2.5 O3 findings indicate exert specific regions time periods. A more in-depth be achieved later

Language: Английский

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Insights from an Integrated LC–MS/MS and Machine Learning Analysis into the Role of Long-Chain CHO-Containing Compounds in Ambient Light-Absorbing Aerosols

Environmental Science & Technology Letters, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 29, 2024

Fossil fuel combustion, biomass burning, and cooking are major emission sources of urban organic aerosols, which have a significant impact on human health global radiative forcing. This study collected ambient PM2.5 in Shanghai, China, along with particulate matter from biodiesel/diesel-fueled vehicles, bio-oil pyrolysis, laboratory-scale experiments conducted using Miniature Combustion Aerosol Standard (lab-MINICAST) experiments. Targeted MS/MS HPLC-Q-TOF-MS methodology machine learning were applied to investigate decode the light-absorbing chromophores methanol-extracted aerosols. The results showed emissions burning vehicles main contributors CHO compounds accounted for largest proportion. A fraction identified long-chain CHO-containing compounds, including fatty acids (C18H34O2, C18H32O2, C16H30O2, C5H8O2, subset CnH2nO2 (12 < n 25)) acid methyl esters (FAMEs, remaining originatimg vehicle emissions, accounting 65.256% aerosol during nonbiomass days, but only 7.12% 3.06% Long Short-Term Memory (LSTM) models revealed that all molecules samples this typically exhibit higher weights atomic around oxygen-containing functional groups (>0.5), contrasting non-light-absorbing substances, display more uniformly distributed lower weights. may provide some explanation ability FAMEs.

Language: Английский

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Molecular Characterization of Atmospheric Organic Aerosols: Contemporary Applications of High-resolution Mass Spectrometry

TrAC Trends in Analytical Chemistry, Journal Year: 2024, Volume and Issue: 181, P. 117986 - 117986

Published: Sept. 25, 2024

Language: Английский

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