Molecular-level insights into the temperature-dependent formation dynamics and mechanism of water-soluble dissolved organic carbon derived from biomass pyrolysis smoke

Water Research, Journal Year: 2024, Volume and Issue: 252, P. 121176 - 121176

Published: Jan. 21, 2024

Language: Английский

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Unveiling the Molecular Characteristics, Origins, and Formation Mechanism of Reduced Nitrogen Organic Compounds in the Urban Atmosphere of Shanghai Using a Versatile Aerosol Concentration Enrichment System

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: 58(16), P. 7099 - 7112

Published: March 27, 2024

Reduced nitrogen-containing organic compounds (NOCs) in aerosols play a crucial role altering their light-absorption properties, thereby impacting regional haze and climate. Due to the low concentration levels of individual NOCs air, utilization accurate detection quantification technologies becomes essential. For first time, this study investigated diurnal variation, chemical characteristics, potential formation pathways urban ambient Shanghai using versatile aerosol enrichment system (VACES) coupled with HPLC-Q-TOF-MS. The results showed that accounted over 60% identified components aerosols, O/N < 3 being major contributors (>70%). predominance positive ionization mode suggested prevalence reduced NOCs. Higher relative intensities number fractions were observed during nighttime, while CHO an opposite trend. Notably, correlation between intensity ammonium nighttime was observed, suggesting reaction form imines may be pathway for nighttime. Seven prevalent types autumn winter characterized by CH2 long-chain homologues. These included alkyl, cyclic, aromatic amides CHON compounds, as well heterocyclic or cyclic amines aniline homologue series CHN which associated anthropogenic activities capable forming light-absorbing chromophores posing harm human health. findings highlight significant contributions both primary emissions chemistry, particularly amination processes, pollution Shanghai's atmosphere.

Language: Английский

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Elucidating Secondary Organic Aerosol Processes through High-Resolution Aerosol Mass Spectrometry in Beijing

Advances in Atmospheric Sciences, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 24, 2025

Language: Английский

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Optical properties, chemical functional group, and oxidative activity of different polarity levels of water-soluble organic matter in PM2.5 from biomass and coal combustion in rural areas in Northwest China

Atmospheric Environment, Journal Year: 2022, Volume and Issue: 283, P. 119179 - 119179

Published: May 17, 2022

Language: 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, Journal Year: 2023, Volume and Issue: 57(51), P. 21570 - 21580

Published: Nov. 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.

Language: Английский

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

Environmental Science & Technology, Journal Year: 2023, Volume and Issue: 57(43), P. 16500 - 16511

Published: Oct. 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.

Language: Английский

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Biostimulants in dissolved organic matters recovered from anaerobic digestion sludge with alkali-hydrothermal treatment: Nontarget identification by ultrahigh-resolution mass spectrometry

Environment International, Journal Year: 2023, Volume and Issue: 173, P. 107813 - 107813

Published: Feb. 11, 2023

Recovering high-value biomaterials from anaerobic digestion sludge (ADS) has attracted considerable attention. However, the molecular features and biological effects of abundant dissolved organic matters (DOMs) in ADS are still unclear, which limits efficient recycling application these bioproducts. This study investigated composition transformation DOMs recovered through a mild-temperature alkali-hydrothermal treatment (AHT) with ultrahigh-resolution mass spectrometry energy spectroscopy, fertilizing were evaluated by rice hydroponics. The results indicated that AHT processes significantly promoted solubilization release ADS, where most molecules remained unchanged mainly consisted N-containing compounds 1-3 N atoms, featuring aromatic or N-heterocyclic rings. Furthermore, at pH 9-10 induced hydrolysis partial protein-like substances DOMs, was accompanied formation heterocyclic-N compounds. Under 11-12, increasingly decomposed into amino-N containing 1 5 while numerous oxygenated phytotoxicity degraded removed DOMs. Rice hydroponic test verified ADS-derived process 12 exhibited highest bioactivity for growth, attributed to abundance amino humic substances. proposed novel recovery high-quality liquid fertilizer process, can further enrich technical options available safe utilization resources.

Language: Английский

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Measurement report: Changes in light absorption and molecular composition of water-soluble humic-like substances during a winter haze bloom-decay process in Guangzhou, China

Atmospheric chemistry and physics, Journal Year: 2023, Volume and Issue: 23(2), P. 963 - 979

Published: Jan. 20, 2023

Abstract. Water-soluble humic-like substances (HULIS) absorb light in near-UV and visible wavelengths exert significant influence on the atmospheric environment climate. However, knowledge HULIS evolution during haze bloom-decay process is limited. Herein, PM2.5 samples were obtained a winter event Guangzhou, China, absorption molecular composition of investigated by UV–Vis spectrophotometry ultrahigh-resolution mass spectrometry. Compared with clean days, coefficients (Abs365) days significantly higher but efficiencies (MAE365) relatively low, suggesting diverse dynamic properties episodes. The CHO CHON compounds most abundant components HULIS, followed CHOS, CHONS, CHN. Haze presented comparatively high weight; lower aromaticity index (AImod); O/Cw, O/Nw, O/Sw ratios, indicating that fractions undergo oxidation compared to days. Moreover, AImod major potential chromophores contributed absorption. It worth noting proportions these decreased events, mainly owing their Besides, accumulated contribution organic emitted from vehicles formed reactions biogenic volatile (bio-VOCs) also diluted light-absorbing HULIS. These findings help us understand processes subtropic region China.

Language: Английский

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Measurement report: Characteristics of nitrogen-containing organics in PM_2.5 in Ürümqi, northwestern China – differential impacts of combustion of fresh and aged biomass materials

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(7), P. 4331 - 4346

Published: April 15, 2024

Abstract. Nitrogen-containing organic compounds (NOCs) are abundant and important aerosol components deeply involved in the global nitrogen cycle. However, sources formation processes of NOCs remain largely unknown, particularly city (Ürümqi, China) farthest from ocean worldwide. Here, PM2.5 collected Ürümqi over a 1-year period were characterized by ultra-high-resolution mass spectrometry. The abundance CHON (mainly oxygen-poor unsaturated aliphatic-like species) positive ion mode was higher warm than cold period, which attributed to contribution fresh biomass material combustion (e.g., forest fires) associated with amidation fatty acids rather oxidation processes. nitro-aromatic negative increased significantly tightly related aged dry straws) wintertime Ürümqi. For CHN compounds, alkyl nitriles aromatic species showed periods, respectively. Alkyl can be derived dehydration amides (the main period). In contrast, burning. These findings further suggested different impacts materials on NOC compositions seasons. overall results shed light mechanisms release during combustion.

Language: Английский

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Unraveling the Light‐Absorbing Properties of Brown Carbon at a Molecular Level

Geophysical Research Letters, Journal Year: 2024, Volume and Issue: 51(10)

Published: May 15, 2024

Abstract Brown carbon (BrC) exhibits a highly complex chemical composition with diverse light‐absorbing properties, which complicates our understanding of its climate impacts. This study examined the impact molecular characteristics (including mass, unsaturation, oxidation state, and polarity) heteroatoms on properties (absorptivity wavelength dependence) BrC from perspective, based ultraviolet‐visible spectra over 40,000 substances in aerosol different sources ambience. Our findings reveal that light‐absorptivity molecules increases decreasing polarity O/C ratio, while it rises higher mass unsaturation. We developed predictive models for absorptivity double bond equivalent ratio. In addition, we observed an inverse correlation between dependence at level, as determined through mathematical analysis. molecular‐level provides valuable insights into absorbing mechanisms, facilitating more accurate characterization atmospheric models.

Language: Английский

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