pH affects the aqueous-phase nitrate-mediated photooxidation of phenolic compounds: implications for brown carbon formation and evolution

Environmental Science Processes & Impacts, Год журнала: 2022, Номер 25(2), С. 176 - 189

Опубликована: Март 16, 2022

Brown carbon (BrC) is known to have important impacts on atmospheric chemistry and climate. Phenolic compounds are a prominent class of BrC precursors that emitted in large quantities from biomass burning fossil fuel combustion. Inorganic nitrate ubiquitous component aqueous phases such as cloudwater, fog, aerosols. The photolysis inorganic can lead formation via the photonitration phenolic phase. However, acidity phase adds complexity these processes needs be considered when investigating nitrate-mediated photooxidation compounds. In this study, we investigated influence pH evolution aqueous-phase guaiacol, catechol, 5-nitroguaiacol, 4-nitrocatechol initiated by photolysis. reaction rates, composition were found depend pH. Guaiacol, 5-nitroguaiacol reacted substantially faster at lower contrast, slower rates For all four compounds, initial stages resulted an increase light absorption (i.e., photo-enhancement) near-UV visible range due absorbing products formed addition nitro and/or hydroxyl groups compound. Greater photo-enhancement was observed during guaiacol catechol. greater higher 4-nitrocatechol. This indicated effect has yields not universal, will These results provide new insights into how influences reactivities different formation/evolution photolysis, which significant implications for fates modeled areas with high levels nitrate.

Язык: Английский

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3D urchin–like CoVO/MXene nanosheet composites for enhanced detection signal of nitrite

Sensors and Actuators B Chemical, Год журнала: 2022, Номер 378, С. 133207 - 133207

Опубликована: Дек. 20, 2022

Язык: Английский

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Co-photolysis of mixed chromophores affects atmospheric lifetimes of brown carbon

Environmental Science Atmospheres, Год журнала: 2023, Номер 3(8), С. 1145 - 1158

Опубликована: Янв. 1, 2023

Sensitizing shortens the atmospheric lifetimes of BrC chromophores and potentially other species during (co-)photolysis, while shadowing only works in coarse particles.

Язык: Английский

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Enhanced HONO Formation from Aqueous Nitrate Photochemistry in the Presence of Marine Relevant Organics: Impact of Marine-Dissolved Organic Matter (m-DOM) Concentration on HONO Yields and Potential Synergistic Effects of Compounds within m-DOM

ACS ES&T Air, Год журнала: 2024, Номер 1(6), С. 525 - 535

Опубликована: Апрель 30, 2024

Nitrous acid (HONO) is a key molecule in the reactive nitrogen cycle. However, sources and sinks for HONO are not fully understood. Particulate nitrate photochemistry has been suggested to play role formation of marine boundary layer (MBL). Here we investigate impact relevant organic compounds on from aqueous photochemistry. In particular, steady-state, gas-phase yields were measured irradiated solutions at low pH containing marine-dissolved matter (m-DOM). m-DOM induces nonlinear increase yield across all concentrations compared that pure solutions, with rates increasing by up 3-fold when present. Furthermore, understand potential synergistic effects may occur within complex samples such as m-DOM, mixtures chromophoric (light-absorbing) aliphatic (non-light-absorbing) molecular proxies utilized. 4-benzoylbenzoic (4-BBA) ethylene glycol (EG) acidic showed more upon irradiation only one proxies. This suggests can samples. Atmospheric implications results presented here discussed.

Язык: Английский

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Important yet Overlooked HONO Source from Aqueous-phase Photochemical Oxidation of Nitrophenols

Environmental Science & Technology, Год журнала: 2024, Номер 58(35), С. 15722 - 15731

Опубликована: Авг. 23, 2024

Nitrites (NO

Язык: Английский

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Coarse particles compensate for missing daytime sources of nitrous acid and enhance atmospheric oxidation capacity in a coastal atmosphere

The Science of The Total Environment, Год журнала: 2024, Номер 915, С. 170037 - 170037

Опубликована: Янв. 15, 2024

Язык: Английский

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Organic peroxyl radicals from biacetyl accelerated the visible-light degradation of steroid estrogens in aqueous solution

Chemosphere, Год журнала: 2024, Номер 351, С. 141195 - 141195

Опубликована: Янв. 17, 2024

Язык: Английский

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Aqueous production of sulfur-containing aerosols from nitroaromatic compounds and SO2 in wintertime urban haze

Science Bulletin, Год журнала: 2025, Номер unknown

Опубликована: Март 1, 2025

Язык: Английский

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Photosensitizers Regulate Nitrate Photoproduct Yields in Bulk Aqueous Matrices

Environmental Science & Technology, Год журнала: 2025, Номер unknown

Опубликована: Март 17, 2025

Photolysis of nitrate (NO3-) in the presence photosensitizers is thought to promote release atmospherically important reactive nitrogen species (NOy), such as HONO, via mechanisms that are poorly understood. To address this knowledge gap, we conducted photochemistry studies on mixtures NO3-, a model photosensitizer [4-benzoylbenzoic acid (4-BBA)], and various aliphatic organic matter proxies. We found enhances production NOy superoxide (O2-) from bulk aqueous photolysis, while addition 4-BBA decreases O2- yields most cases. This effect was not observed heterogeneous systems, where enhanced photochemical when coadsorbed with NO3- silica surfaces. demonstrates act both oxidants reductants, regulating oxygen photochemistry. Given sufficient residence time phase, photoproducts can be scavenged secondary reactions photosensitizers. In aerosol systems high surface area-to-volume ratios, however, volatilization favored, less affected by chromophoric sinks phase. work intricate role moieties natural conversion (i.e., renoxification) atmosphere.

Язык: Английский

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Contribution of Reactive Species to Nitrogen Transformation during Radiolytic Degradation of Aniline

ACS ES&T Engineering, Год журнала: 2025, Номер unknown

Опубликована: Март 25, 2025

Язык: Английский

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