Separation and Purification Technology, Journal Year: 2022, Volume and Issue: 304, P. 122364 - 122364
Published: Oct. 15, 2022
Language: Английский
The Journal of Physical Chemistry A, Journal Year: 2023, Volume and Issue: 127(44), P. 9302 - 9310
Published: Oct. 25, 2023
Enhanced photolysis of particulate nitrate (pNO3) to form photolabile species, such as gas-phase nitrous acid (HONO), has been proposed a potential mechanism recycle nitrogen oxides (NOx) in the remote boundary layer ("renoxification"). This article presents series laboratory experiments aimed at investigating parameters that control pNO3 and efficiency HONO production. Filters on which artificial or ambient particles had sampled were exposed light solar simulator, formation was monitored under controlled conditions. The results indicate is enhanced, compared HNO3, low levels, with enhancement factor reducing higher levels. presence cations (Na+) halides (Cl-) photosensitive organic compounds (imidazole) also enhance photolysis, but other oxalate succinic have opposite effect. precise role humidity remains unclear. While enhanced deliquescent dry particles, some experimental suggest this may not be case for supersaturated particles. These both composition potentially explaining variability among previous field studies. observations marine can explained by simple box-model includes pNO3, line presented here, although more work needed order derive comprehensive parametrization process.
Language: Английский
Citations
9
Journal of Geophysical Research Atmospheres, Journal Year: 2024, Volume and Issue: 129(3)
Published: Feb. 2, 2024
Abstract Humic‐like substances (HULIS) are a ubiquitous reactive component of atmospheric aerosol. They participate in the formation secondary organic aerosols via chemical reactions with oxidants. Here, we assess influence transition metal ions (namely ferric iron, Fe(III)), and nitrate () on heterogeneous reaction gaseous NO 2 an aqueous film containing gallic acid (GA) or tannic (TA) as proxies for HULIS. Using vertical wetted wall flow tube technique, uptake coefficients GA TA increased nonlinearly increasing [Fe(III)], dark under light irradiation. However, combined effect both ions, Fe(III) , led to substantial decrease simulated near‐UV sunlight irradiation (300 < λ 400 nm). The lifetime dilute phase, which corresponds cloud water, due would be 6 hr during nighttime daytime. aerosol particles contain that is, increase 27 11 days light‐induced . Also, observed, using Fourier transform ion cyclotron resonance mass spectrometry, nitrocatechols compounds (e.g., methyl‐nitrocatechol), contribute brown carbon. Compounds reduced functional groups such amines were also observed presence iron irradiation, indicating can kinetics product distribution deliquescent particles.
Language: Английский
Citations
2
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
Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(22), P. 12575 - 12593
Published: Nov. 14, 2024
Abstract. Nitrous acid (HONO) is a main precursor of hydroxyl radicals (OH), which contribute to the formation numerous secondary air pollutants in troposphere. Despite its importance atmospheric chemistry, HONO chemistry has not been fully incorporated into many chemical transport models (CTMs). Due lack processes, CTM simulations often tend underestimate mixing ratios HONO. This study was undertaken because with current Community Multiscale Air Quality (CMAQ) model have strong tendency ratio. In search missing sources HONO, we attempted sequentially incorporate following potential and processes CMAQ modeling framework: (i) gas-phase reactions, (ii) traffic emissions, (iii) soil (iv) heterogeneous production on surfaces aerosols, (v) tree leaf building surfaces, (vi) photolysis reactions particulates deposited HNO3/nitrates called “renoxification”. The simulation performances modified were then evaluated by comparing modeled observed at Olympic Park station Seoul, South Korea. When added model, average daily increased from 0.06 1.18 ppb. daytime produced run full account found be better agreement observations than those original (CMAQv5.2.1) runs improved statistical metrics (e.g., index (IOA) 0.59 0.68, while mean bias (MB) decreased dramatically −0.57 −0.34 ppb). addition, investigated contributions individual ratios, as well impacts concentrations other species All these issues are also discussed this paper.
Language: Английский
Citations
2
Separation and Purification Technology, Journal Year: 2022, Volume and Issue: 304, P. 122364 - 122364
Published: Oct. 15, 2022
Language: Английский
Citations
10