Reply on RC1 DOI Creative Commons
Liyuan Zhou

Published: March 30, 2023

Abstract. Atmospheric oxidation of sulfur dioxide (SO2) to sulfate has been widely investigated by means gas-phase and in-cloud chemistry studies. Recent field measurements have shown significant formation in cloud-free environments with high aerosol loadings. As an important fraction biomass burning components, particulate phenolic non-phenolic aromatic carbonyls may initiate photosensitized multiphase SO2 aerosols, which our knowledge however is still its nascent stage. In this study, on the basis single-particle mass spectrometry (SPAMS) measurements, we find evident biomass-burning-derived photosensitizer particles under UV exposure, attributable S(IV), while almost no was observed dark conditions. The efficiency production irradiation, represented number percentage sulfate-containing (99 %–43 %) relative peak area (RPA) (0.67–0.12) spectra, descending order, were 3,4-dimethoxybenzaldehyde (DMB), vanillin (VL) syringaldehyde (SyrAld). Internal mixtures VL potassium nitrate (KNO3) gave a slightly lower RPA than alone. externally mixed KNO3 particles, predominantly formed former, confirming that via photosensitization prevails over photolysis. Our results suggest S(IV) could make contribution formation, especially areas influenced burning.

Language: Английский

Aqueous-Phase Photooxidation of Vanillin in the Presence of Nitrite: Characteristics, Products, and Mechanism DOI
Min Cai,

Zhengyu Zhao,

Xingru Li

et al.

ACS ES&T Air, Journal Year: 2024, Volume and Issue: 1(8), P. 860 - 870

Published: June 17, 2024

The present study investigates the reaction characteristics and mechanisms involved in aqueous-phase photooxidation of vanillin (VL) presence nitrite (NO2–). research entails a comprehensive analysis decay kinetics VL, composition products, changes absorbance under different pH conditions VL/NO2– molar ratios. results indicate notably rapid rate VL acidic conditions, with ratio emerging as crucial factor process. Notably, photoreaction between NO2– leads to formation secondary organic aerosols (aqSOA) comprising hydroxylation nitration oligomers that exhibit strong absorption near-ultraviolet visible light regions. findings, through theoretical calculations, shed on pathways This investigation contributes valuable insights into atmospheric phenolic compounds initiated by NO2–. obtained are particularly significant for understanding evolution aqSOA brown carbon (BrC).

Language: Английский

Citations

2
Effects of Copper on the Chemical Kinetics and Brown Carbon Formation in the Aqueous ∙OH oxidation of Phenolic Compounds DOI
Junwei Yang,

Tianye Zhou,

Yuting Lyu

et al.

Environmental Science Processes & Impacts, Journal Year: 2024, Volume and Issue: 26(9), P. 1526 - 1542

Published: Jan. 1, 2024

Many phenolic compounds (PhCs) in biomass burning and fossil fuel combustion emissions can partition into atmospheric aqueous phases (

Language: Английский

Citations

2
Complexities of Photosensitization in Atmospheric Particles DOI Creative Commons
Zhancong Liang, Yongjie Li,

Brix Raphael Go

et al.

ACS ES&T Air, Journal Year: 2024, Volume and Issue: 1(11), P. 1333 - 1351

Published: Oct. 10, 2024

Brown carbons (BrCs) play a pivotal role in the light absorption by aerosol particulates exerting positive radiative forcing effect that contributes to global warming. Beyond impacts on balance, some BrCs, as photosensitizers, can generate reactive triplet-state molecules toward various atmospheric upon photoexcitation. The significance of photosensitization has been increasingly recognized, particularly context escalated wildfire incidents emit substantial BrCs. We focus complex discussing current challenges, including (1) diverse reactivities photosensitizer mixture particles, (2) methodologies for investigating processes, (3) driving factors photosensitization, and (4) typical pathways mechanisms photosensitized reactions. Lastly, we advise future research refined parametrization triplet singlet oxygen concentrations, alongside their reactivities.

Language: Английский

Citations

2
Aqueous photochemical aging of water-soluble smoke particles from crop straws burning DOI

Zhaolian Ye,

Dandan Hu, Zixuan Wang

et al.

Atmospheric Environment, Journal Year: 2024, Volume and Issue: unknown, P. 120897 - 120897

Published: Oct. 1, 2024

Language: Английский

Citations

2
Multiphase Guaiacol Photooxidation: Fenton Reactions, Brown Carbon, and Secondary Organic Aerosol Formation in Suspended Aerosol Particles DOI
David O. De Haan, Lelia N. Hawkins, Jacob A. Weber

et al.

ACS ES&T Air, Journal Year: 2024, Volume and Issue: 1(5), P. 346 - 356

Published: March 28, 2024

Guaiacol, present in wood smoke, readily forms secondary organic aerosol (SOA), and, the aqueous phase, brown carbon (BrC) species. Here, BrC is produced an illuminated chamber containing guaiacol(g), HOOH(g) as OH radical source, and either deliquesced salt particles or guaiacol SOA at 50% relative humidity. production slows without source (HOOH), likely due to low levels of generation by photosensitization, perhaps involving surface-adsorbed dissolved oxygen. With HOOH, mass absorption coefficients 365 nm generated + reaction reach a maximum ∼6 h atmospheric exposure, after which photobleaching becomes dominant. In presence soluble iron but no more produced, insoluble polymer observed previous studies. However, with both HOOH (enabling Fenton chemistry), significantly less are very high oxidation rates, average state reaches 2, indicating carboxylate products like oxalate. These results indicate that formation photooxidation can take place over wider range conditions than previously thought effects iron(II) depend on HOOH. Multiphase makes significant contribution producing highly oxidized material smoke plumes.

Language: Английский

Citations

1
Liquid phase transformation mechanism of β- caryophyllonic acid initiated by hydroxyl radicals and ozone in atmosphere DOI

Chongwen Sun,

Xiaoyu Liu, Ning Wang

et al.

Chemosphere, Journal Year: 2024, Volume and Issue: 364, P. 143257 - 143257

Published: Sept. 1, 2024

Language: Английский

Citations

1
Unsaturated Fatty Acids Enhance Aqueous Atmospheric Oxidation Ability by Producing Oxygen‐Containing Radicals in Fog Droplets DOI
Ning Yang, Qiaorong Xie, Xinxing Zhang

et al.

Journal of Geophysical Research Atmospheres, Journal Year: 2023, Volume and Issue: 128(14)

Published: July 4, 2023

Abstract The surface of atmospheric aqueous aerosol is covered with an organic film. However, there have been limited studies about the photochemical process between coating and samples such as fogwater, which contains light absorbing brown carbon (BrC). Here, interactional aging unsaturated fatty acids was performed by laboratory field observations. On one hand, glycine alanine were selected nitrogen‐containing compounds to form BrC carbonyl like glyoxal or methylglyoxal. Oleic acid induced peroxy radicals through H‐abstraction excited triplet hydroxyl radical (OH). other type formation pathway Criegee intermediates (CIs) proposed oxidation oleic acid. CIs may be formed OH addition C=C bonds scavenged interfacial reactions. Results from ultra‐high resolution Fourier transform ion cyclotron resonance mass spectrometry show that synergistic effect a higher oxidative capacity than OH. Furthermore, our study demonstrates can improve ability producing oxygen‐containing radicals. These findings highlight free greatly influenced reactions, further reveal complexities fog chemistry.

Language: Английский

Citations

3
Photoinduced Reactions of Nitrate in Aqueous Microdroplets by Triplet Energy Transfer DOI
Pyeongeun Kim,

Christian Boothby,

Vicki H. Grassian

et al.

The Journal of Physical Chemistry Letters, Journal Year: 2023, Volume and Issue: 14(47), P. 10677 - 10684

Published: Nov. 21, 2023

In-situ Raman spectroscopy of single levitated charged aqueous microdroplets irradiated by dual-beam (266 and 532 nm) lasers demonstrates that the nitrate anion (NO3-) can be depleted in droplet through an energy transfer mechanism following excitation sulfanilic acid (SA), a UV-absorbing aromatic organic compound. Upon 266 nm irradiation, fast decrease NO3- concentration was observed when SA is present droplet. This photoinduced reaction occurs without direct photolysis NO3-. Instead, rate depletion found to depend on initial pH Based absorption-emission spectral analysis excited-state calculations, triplet-triplet between proposed as underlying for microdroplets. These results suggest mechanisms initiated light-absorbing molecules may play significant role photochemistry.

Language: Английский

Citations

3
UHPLC/FT-MS NON-TARGETED SCREENING APPROACH FOR BIOMASS BURNING ORGANIC AEROSOL AND LIQUID SMOKE AS BIOMASS BURNING ORGANIC AEROSOL SURROGATE DOI Creative Commons
Thusitha Divisekara

Published: Jan. 1, 2023

Biomass combustion contributes a large amount of aerosol particles to the atmosphere impacting climate system and human health. Identifying molecular composition biomass burning organic (BBOA) is challenging because its complex nature. Liquid chromatography mass spectrometric non-targeted screening (NTS) methods provide comprehensive analysis. However, instrumentation data analysis are due extreme complexity environmental samples. In first part this study, we implemented new LC/FT-MS processing approach by combining existing open-source tools, MZmine2.53 MFAssignR. The method's validity was checked using standard polyacrylic acid (PAA) mixture. Then analyze BBOA with commercial liquid smoke as surrogate. Our significantly improves identification successfully resolving limitations Further, results were consistent more robust direct infusion FT-MS method, confirming that it demonstrates significant advance in obtaining structural semi-quantitative information about level aerosol. Mimicking ambient one challenges scientists face atmospheric science. Therefore, second improve simulate mixing them different additives. We found those additives further enhance chemistry match BBOA. This could impact research provides an option for environmentally relevant lab studies. Laboratory studies frequently generate fresh smoke. less reproducible, expensive, impracticable perform many conditions. capability (without chemical alteration) surrogate studied next dissertation compared laboratory-generated According comparison, over 90% spectral abundance matched each other, better, inexpensive, readily available

Language: Английский

Citations

1
Liquid Phase Transformation Mechanism of Β- Caryophyllonic Acid Initiated by Hydroxyl Radicals and Ozone In Atmosphere DOI

Chongwen Sun,

Xiaoyu Liu, Ning Wang

et al.

Published: Jan. 1, 2024

β-caryophyllonic acid (BCA), as an important precursor of aqueous secondary organic aerosols (aqSOA), has adverse effects on the atmospheric environment and human health. However, key chemical reaction process in which BCA participates formation is still unclear. In this study, mechanism kinetics with ·OH O3 were investigated by quantum calculations. The initiation reactions between include addition H-abstraction pathways, subsequent intermediate intermediates will also react O2, ultimately undergo a cracking to generate small molecular substances. can primary ozone oxides Criegee Intermediates oIM3, main products keto-BCA, well other molecule SOA precursors. entire improves O/C ratio phase generates molecules such hydroxyacetone, plays role SOA. transformation rate constants initiated are 2.24 × 1010 M-1 s-1 1.85 105 s-1, respectively. At 298K, lifetimes reacting range from 0.56 h 3.54 h, while 0.75 1.50×105 h. This suggests that primarily reacts ·OH. under higher concentrations, its ozonolysis becomes significant, promoting aqSOA. According risk assessment, toxicity most (TPs) gradually decreased, but residual developmental could not be ignored. paper, liquid oxidation mechanisms sesquiterpene unsaturated derived studied microscopic level, guiding significance for aqSOA atmosphere.

Language: Английский

Citations

0