Multiphase Oxidation of Sulfur Dioxide in Aerosol Particles: Implications for Sulfate Formation in Polluted Environments

Environmental Science & Technology, Journal Year: 2021, Volume and Issue: 55(8), P. 4227 - 4242

Published: March 24, 2021

Atmospheric oxidation of sulfur dioxide (SO2) forms sulfate-containing aerosol particles that impact air quality, climate, and human ecosystem health. It is well-known in-cloud SO2 frequently dominates over gas-phase on regional global scales. Multiphase involving particles, fog, cloud droplets has been generally thought to scale with liquid water content (LWC) so multiphase would be negligible for due their low LWC. However, recent field evidence, particularly from East Asia, shows fast sulfate formation prevails in cloud-free environments are characterized by high loadings. By assuming the kinetics chemistry most atmospheric models do not capture this phenomenon. Therefore, blossomed past decade, many processes proposed bridge difference between modeled observed mass This review summarizes advances fundamental understanding SO2, a focus environmental conditions affect rate, experimental challenges, mechanisms results individual reaction pathways, future research directions. Compared dilute conditions, paper highlights differences arise at molecular level extremely solute strengths present particles.

Language: Английский

---

Oxidation of sulfur dioxide by nitrogen dioxide accelerated at the interface of deliquesced aerosol particles

Nature Chemistry, Journal Year: 2021, Volume and Issue: 13(12), P. 1173 - 1177

Published: Sept. 30, 2021

Language: Английский

---

Engine emissions with air pollutants and greenhouse gases and their control technologies

Journal of Cleaner Production, Journal Year: 2022, Volume and Issue: 376, P. 134260 - 134260

Published: Sept. 22, 2022

Language: Английский

---

Spontaneous dark formation of OH radicals at the interface of aqueous atmospheric droplets

Proceedings of the National Academy of Sciences, Journal Year: 2023, Volume and Issue: 120(15)

Published: April 3, 2023

Hydroxyl radical (OH) is a key oxidant that triggers atmospheric oxidation chemistry in both gas and aqueous phases. The current understanding of its sources mainly based on known bulk (photo)chemical processes, uptake from gaseous OH, or related to interfacial O

Language: Английский

---

Spontaneous Reduction of Transition Metal Ions by One Electron in Water Microdroplets and the Atmospheric Implications

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(5), P. 2800 - 2805

Published: Jan. 27, 2023

Freshman chemistry teaches that Fe3+ and Cu2+ ions are stable in water solutions, but their reduced forms, Fe2+ Cu+, cannot exist as the major oxidation state due to fast by O2 and/or disproportionation. Contrary these well-known facts, significant fractions of dissolved Fe Cu species states atmospheric such deliquesced aerosols, clouds, fog droplets. Current knowledge attributes phenomena stabilization lower complexation ligands various photochemical or thermal pathways can reduce higher states. In this study, spraying solutions transition metal into microdroplets, we show results spontaneous reduction ligated Fe(III) Cu(II) Fe(II) Cu(I) species, presenting a previously unknown source water. It is spontaneously generated electrons microdroplets responsible for reduction. Control experiments atmosphere glove box filled with precisely controlled gaseous contents reveal O2, CO2, NO2 competitors electrons, forming O2-, HCO2-, NO2-, respectively. Taking findings together, opine microdroplet might play underestimated roles redox chemistry.

Language: Английский

---

Aerosol pH and chemical regimes of sulfate formation in aerosol water during winter haze in the North China Plain

Atmospheric chemistry and physics, Journal Year: 2020, Volume and Issue: 20(20), P. 11729 - 11746

Published: Oct. 17, 2020

Abstract. Understanding the mechanism of haze formation is crucial for development deliberate pollution control strategies. Multiphase chemical reactions in aerosol water have been suggested as an important source particulate sulfate during severe (Cheng et al., 2016; Wang 2016). While key role has commonly accepted, relative importance different oxidation pathways aqueous phase still under debate mainly due to questions about pH. To investigate spatiotemporal variability pH and winter North China Plain (NCP), we developed a new chemistry (AWAC) module WRF-Chem model (Weather Research Forecasting coupled with Chemistry). Using WRF-Chem-AWAC model, performed comprehensive survey atmospheric conditions characteristic wintertime NCP focusing on January 2013. We find that exhibited strong vertical gradient distinct diurnal cycle which was closely associated variation abundance acidic alkaline fine particle components their gaseous counterparts. Over Beijing, average at surface layer ∼5.4 remained nearly constant around ∼5 up ∼2 km above ground level; further aloft, acidity rapidly increased ∼0 ∼3 km. The pattern increasing altitude persisted over NCP, while specific levels gradients varied between regions. In region north ∼41∘ N, mean values level were typically greater than 6, main pathway S(IV) by ozone. South range 4.4 5.7, regimes reaction prevailed four regions depending reactant concentrations conditions. NO2 megacity Beijing large area Hebei Province south west well part Shandong Province. transition metal ion (TMI) dominated inland coastal east H2O2 extending (Shandong Henan provinces). all these regions, O3 TMI water, gas-particle partitioning H2SO4 vapor, became more altitude. Sensitivity tests show rapid production can be maintained wide (e.g., =4.2–5.7) transitions from dominant NO2∕O3 regimes.

Language: Английский

---

PM2.5-bound elements in Hebei Province, China: Pollution levels, source apportionment and health risks

The Science of The Total Environment, Journal Year: 2021, Volume and Issue: 806, P. 150440 - 150440

Published: Sept. 21, 2021

Language: Английский

---

Impacts of biogenic emissions from urban landscapes on summer ozone and secondary organic aerosol formation in megacities

The Science of The Total Environment, Journal Year: 2021, Volume and Issue: 814, P. 152654 - 152654

Published: Dec. 30, 2021

Language: Английский

---

Single-particle Raman spectroscopy for studying physical and chemical processes of atmospheric particles

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(5), P. 3017 - 3044

Published: March 7, 2022

Abstract. Atmospheric particles experience various physical and chemical processes change their properties during lifetime. Most studies on atmospheric particles, both in laboratory field measurements, rely analyzing an ensemble of particles. Because different mixing states individual only average can be obtained from using ensembles To better understand the fate environmental impacts investigations at a single-particle level are valuable. Among wealth analytic techniques, Raman spectroscopy provides unambiguous characterization under pressure non-destructive situ manner. This paper comprehensively reviews application such technique including particle hygroscopicity, phase transition separation, solute–water interactions, pH, multiphase reactions. Investigations enhanced bioaerosols basis also reviewed. For each application, we describe principle representative examples studies. Finally, present our views future directions development further applications studying

Language: Английский

---

Targeting Atmospheric Oxidants Can Better Reduce Sulfate Aerosol in China: H₂O₂ Aqueous Oxidation Pathway Dominates Sulfate Formation in Haze

Environmental Science & Technology, Journal Year: 2022, Volume and Issue: 56(15), P. 10608 - 10618

Published: July 5, 2022

Particulate sulfate is one of the most important components in atmosphere. The observation rapid aerosol production during haze events provoked scientific interest multiphase oxidation SO2 aqueous particles. Diverse pathways can be enhanced or suppressed under different acidity levels and high ionic strength conditions atmospheric aerosol. importance to chemistry has been verified laboratory conditions, though studies actual atmosphere are still limited. By utilizing online observations developing an improved solute strength-dependent chemical thermodynamics kinetics model (EF-T&K model, EF enhancement factor that represents effect on aqueous-phase reaction), we provided quantitative evidence H2O2 pathway was nearly 100 times dominated formation for entire years (66%) Tianjin (a northern city China). TMI (oxygen catalyzed by transition-metal ions) (14%) NO2 got second-highest contributions. Machine learning supported result more affected pathway. collaborative effects oxidants were further investigated using EF-T&K model. Our findings highlight effectiveness adopting target oxidant control as a new direction sustainable mitigation sulfate, given already low concentrations China.

Language: Английский

---