Integrating Chemical Mechanisms and Feature Engineering in Machine Learning Models: A Novel Approach to Analyzing HONO Budget DOI
Dongyang Chen, Li Zhou, Weigang Wang

et al.

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

Published: Dec. 5, 2024

Nitrous acid (HONO) serves as the primary source of OH radicals in atmosphere, exerting significant impacts on atmospheric secondary pollution. The heterogeneous reactions NO2 surfaces and photolysis particulate nitrate or adsorbed nitric are important sources HONO, yet corresponding kinetic parameters based laboratory investigations field observations exhibit considerable variations. In this study, we developed an explainable machine learning model to analyze HONO budget using two years summer urban supersite observations. By integrating chemical mechanisms feature engineering into our model, assessed contributions different inferred for formation pathways, thereby partially addressing limitations associated with predetermined rate coefficients. Our findings revealed that daytime was both aerosol ground surfaces, accounting over 40% its unknown sources. This followed by photoenhanced conversion nitrate. Additionally, derived parameters, analyzed their influencing factors, confirmed methods hold great potential study budget.

Language: Английский

Resolving the overlooked photochemical nitrophenol transformation mechanism induced by nonradical species under visible light DOI Creative Commons
Shujun Liu, Hong Wang,

Zehui Hu

et al.

Proceedings of the National Academy of Sciences, Journal Year: 2024, Volume and Issue: 121(30)

Published: July 17, 2024

Nitrophenols present on the surface of particulates are ubiquitous in atmosphere. However, its atmospheric photochemical transformation pathway remains unknown, for which crucial effect visible light is largely overlooked, resulting an incomplete understanding effects nitrophenols environment. This study delves into photolysis mechanism 4-nitrophenol (4NP), one most abundant nitrophenol compounds, photoactive under irradiation. Unexpectedly, nonradical species (singlet oxygen,

Language: Английский

Citations

3
Formic Acid-Intensified Photoreduction of NOx on Iron Minerals Triggers Daytime HONO Formation through Active Hydrogen DOI
Ziyue Chen, Hao Li,

Xupeng Liu

et al.

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

Published: Oct. 3, 2024

Nitrous acid (HONO) is crucial in atmospheric chemistry as a precursor to morning peak hydroxyl radicals and significantly affects urban air quality by forming secondary pollutants, yet the mechanisms of its daytime formation not fully understood. This study investigates role formic (HCOOH), prevalent electron proton donor, transformation nitrogen oxides (NOx) HONO on photoactive mineral dust. Exploiting hematite (Fe

Language: Английский

Citations

1
Surface Nitrate Enrichment and Enhanced HONO Production from Ionic Surfactant Aggregation at the Aqueous-Air Interface DOI
Qiong Li, Shuaishuai Ma,

Qiuyue Ge

et al.

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

Published: Dec. 5, 2024

Significant discrepancies persist between field observations and model simulations regarding the strength of marine-derived HONO sources, underscoring urgency to resolve unidentified sources. In this study, sodium dodecyl sulfate (SDS) was chosen as a proxy for marine surfactants investigate its impact on aqueous nitrate photolysis first time. Remarkable increases in NO2 production rates by factors 3.3 5.6, respectively, along with 1.9-fold rise NO2– concentration, were observed at very low SDS concentration 0.01 mM, strongly illustrating promoting effect photolysis. Furthermore, an 2 intriguingly aligned critical micelle there additional 41.7% increase rates. Vertically resolved Raman measurements indicated that anions aqueous-air interface attracted NO3– closer surfaces, increasing amount incompletely solvated surface nitrate. Importantly, anionic surfactant exhibited greater compared other typical photochemistry systems addition dissolved organic matter proxy, halogen, photosensitizer, or OH scavenger. These findings offer new insights into sources should be considered concerning budgets NOx, OH, O3.

Language: Английский

Citations

1
Enhanced photochemical formation of active nitrogen species from aqueous nitrate in the presence of halide ions DOI Creative Commons
Yilong Zhao, Chengwei Liu,

Xiang Tu

et al.

Frontiers in Environmental Science, Journal Year: 2024, Volume and Issue: 12

Published: Aug. 20, 2024

Field observations have confirmed that halide ions are widely distributed among aerosols from the marine boundary layer and on surfaces of ice snow in polar regions. Consequently, coexistence may play a more significant role nitrate photolysis than previously thought. In this study, we simultaneously measured HONO, NO 2 , − situ to gain deeper understanding coexisting system, including photogenerated nitrogen products effects rates due enhanced aqueous nitrite HONO transfer by halides. The presence halides significantly increased across various molar ratios ([X – ]/[NO 3 ]) at pH 3.5. By eliminating oxygen flux, transformation primary was affected, resulting higher concentrations N(III) as both . Experiments involving OH scavengers indicated attack from·OH initiated leads side reactions enhance photolysis. Both theoretical calculations actinometry were used determine rate solutions, which together enhances A newly developed model rate, finding ] = 0.2) evaporation solution factors 0.68, 0.95, 1.27 for Cl Br I respectively. To our knowledge, is first determination mass HONO. can be attributed differential surface parallel via ·OH stemming photolysis, with varying leading different quantities nitrogenous products. Additionally, simultaneous measurements photoproducts gas condensed phases recommended better constrain constants

Language: Английский

Citations

1
Influence of bulk-phase acidity, organic fraction, and dissolved oxygen on the photosensitized renoxification of nitrate in NaNO3/humic acid mixtures DOI
Qiong Li,

Wenkai Huang,

Xinyuan Wu

et al.

Journal of Environmental Sciences, Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 1, 2024

Language: Английский

Citations

1
The interplay between aqueous replacement reaction and the phase state of internally mixed organic/ammonium aerosols DOI Creative Commons
Hui Yang,

Fengfeng Dong,

Xia Li

et al.

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(20), P. 11619 - 11635

Published: Oct. 17, 2024

Abstract. Atmospheric secondary aerosols are often internally mixed with organic and inorganic components, particularly dicarboxylic acids, ammonium, sulfate, nitrate, chloride. These complex compositions enable aqueous reaction between species, significantly complicating aerosol phase behavior during aging making predictions challenging. We investigated carboxylate–ammonium salt mixtures using attenuated total reflection Fourier-transformed infrared spectroscopy (ATR-FTIR). The mono-, di-, tricarboxylates included sodium pyruvate (SP), tartrate (ST), citrate (SC), while the ammonium salts NH4NO3, NH4Cl, (NH4)2SO4. Our results demonstrated that replacement reactions carboxylates were promoted by formation depletion of NH3 as relative humidity (RH) changed. For SP/ammonium aerosols, NaNO3 Na2SO4 crystallized from 35.7 % to 12.7 65.7 60.1 RH, respectively, which is lower than values for pure inorganics (62.5 ± 9 %–32 RH 82 7 %–68 5 Na2SO4). Upon hydration, crystalline deliquesced at 88.8 %–95.2 76.5 2 %–81.9 %, higher (74 4 %–98 RH) (65 %–77.1 3 RH). In contrast, ST or SC (NH4)2SO4 was incomplete due gel structure low RH. Unexpectedly, upon humidification in ST/(NH4)2SO4 particles 43.6 then increasing This attributed increased ion mobility viscous particles, leading nucleation growth crystals. findings highlight intricate interplay chemical components within organic/inorganic impact on aging, state, subsequently atmospheric processes.

Language: Английский

Citations

1
Simultaneous Measurement of Gaseous HONO and NO2− in Solutions from Aqueous Nitrate Photolysis Mediated by Organics DOI Creative Commons
Yilong Zhao, Qiong Li,

Xiang Tu

et al.

Atmosphere, Journal Year: 2024, Volume and Issue: 15(11), P. 1279 - 1279

Published: Oct. 25, 2024

Field studies suggest that NO3− photolysis may play a more significant role than previously thought. In this study, we concurrently measured HONO, NO2, and NO2− in situ to gain deeper understanding of the photogenerated HONO transfer air better constrain rate constants photolysis. The presence fatty acids (e.g., nonanoic acid, NA), which are naturally present environment, significantly increases production NO2. With an increase oxygen percentage, release photoinduced slowed, while NO2 accelerated. JNO3− value averaged 1.65 × 10−5 s−1, is two orders magnitude higher values reported similar systems. from solutions increased 2.3 10−4 s−1 5.6 as NA concentration 0.1 20 mM. This can be attributed accumulation induced by at interface. Within interfacial region, becomes prone into gaseous suggesting hosted atmospheric droplets serve temporary reservoir without illumination, influencing oxidizing capacity region for hours. Therefore, simultaneous measurements both gas particle phase photoproducts recommended photolysis, thereby enhancing accuracy predicting photochemical atmosphere.

Language: Английский

Citations

1
Photoreduction of Nitrate to HONO and NOx by Organic Matter in the Presence of Iron and Aluminum DOI

Elizabeth Melssen,

D. L. Bish,

Yaroslav Losovyj

et al.

ACS Earth and Space Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 15, 2024

Nitrogen oxides (NOy) such as NO, NO2, and HONO control the oxidative capacity of lower atmosphere. Studies have shown that photolysis nitrate on atmospheric surfaces is an efficient source nitrogen through a process termed "renoxification;" however, mechanisms responsible for this remain poorly understood, leading to difficulties in modeling composition. This work aims elucidate mechanism NOy formation from model boundary layer comprised mixtures organic matter (citrate Suwanee River fulvic acid) environmentally relevant metals (e.g., Al3+ Fe3+). Results show presence matter, photochemical yields were enhanced by factor between 5 15 compared with pure controls. Known photochemistry are unable explain enhancement, suggesting fraction directly converted strong reductants produced photochemically matter. The addition Fe (hydr)oxides catalyzed both reduction NO2 further NO via Fe2+, which formed photoreduction Fe-organic coordination complexes. In addition, study assesses contribution surface acidity visible light attenuation product yields. results support growing body evidence generated important unrecognized pathway renoxification soil airborne mineral dust aerosols).

Language: Английский

Citations

1
Integrating Chemical Mechanisms and Feature Engineering in Machine Learning Models: A Novel Approach to Analyzing HONO Budget DOI
Dongyang Chen, Li Zhou, Weigang Wang

et al.

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

Published: Dec. 5, 2024

Nitrous acid (HONO) serves as the primary source of OH radicals in atmosphere, exerting significant impacts on atmospheric secondary pollution. The heterogeneous reactions NO2 surfaces and photolysis particulate nitrate or adsorbed nitric are important sources HONO, yet corresponding kinetic parameters based laboratory investigations field observations exhibit considerable variations. In this study, we developed an explainable machine learning model to analyze HONO budget using two years summer urban supersite observations. By integrating chemical mechanisms feature engineering into our model, assessed contributions different inferred for formation pathways, thereby partially addressing limitations associated with predetermined rate coefficients. Our findings revealed that daytime was both aerosol ground surfaces, accounting over 40% its unknown sources. This followed by photoenhanced conversion nitrate. Additionally, derived parameters, analyzed their influencing factors, confirmed methods hold great potential study budget.

Language: Английский

Citations

1