Developments at the AURA atmospheric simulation chamber to characterize chamber volume, air mixing, and charging DOI Creative Commons
Emil Mark Iversen, Merete Bilde, H. B. Pedersen

et al.

Aerosol Science and Technology, Journal Year: 2024, Volume and Issue: unknown, P. 1 - 23

Published: Dec. 10, 2024

We describe three developments at the AURA atmospheric simulation chamber (made of Teflon and with a volume ∼5 m3) aimed an improved understanding physical conditions to facilitate better basis for comparisons between experimental data results from numerical models. First, we demonstrate how can be monitored by observing position wall using fixed laser distance sensors. The absolute calibration is obtained through measurement relative humidity in during controlled dilution experiment. Second, direct measurement, characterize occurrence, magnitude (∼0 – 80 kV/m), decay time (∼10 20 h) static electric fields inside after charging. Further, confirm directly that significantly discharged kept steady mode charging addition ion fans enclosure where suspended. Third, improve air mixing capabilities adding two allows efficient within few minutes. effect field rate measurements particle loss injected polydisperse ammonium sulfate particles.

Language: Английский

Atmospheric oxidation of 1,3-butadiene: influence of seed aerosol acidity and relative humidity on SOA composition and the production of air toxic compounds DOI Creative Commons
Mohammed Jaoui, Klara Nestorowicz, Krzysztof J. Rudziński

et al.

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(2), P. 1401 - 1432

Published: Jan. 31, 2025

Abstract. This study investigated the effect of relative humidity (RH) on chemical composition gas and particle phases formed from photooxidation 1,3-butadiene (13BD) in presence NOx under acidified non-acidified seed aerosol. The experiments were conducted a 14.5 m3 smog chamber operated steady-state mode. Products identified by high-performance liquid chromatography, chromatography–mass spectrometry, ultrahigh-performance chromatography coupled with high-resolution mass spectrometry. More than 50 oxygenated products identified, including 33 organics, 10 organosulfates (OSs), PAN, APAN, glyoxal, formaldehyde, acrolein. Secondary organic aerosol (SOA) reaction depended RH acidity Based Extended Aerosol Inorganics Model (E-AIM), originated solutions was found to exist aqueous solid phases, respectively. Although terms “acidified” “non-acidified” are true for which seeds atomized, there far more fundamental differences between phase states species partition or (aqueous/solid), considerably affects their partitioning formation mechanisms. SOA most (i) higher conditions, where particles deliquescent, did not contain any phase; (ii) increased conditions; (iii) decreased increasing RH. Glyceric acid, threitols, threonic acids, four dimers, three unknowns, among main measured either conditions across all levels. Total secondary carbon yield both conditions. photochemical reactivity 13BD our systems faster To determine contribution ambient aerosol, we analyzed PM2.5 samples collected at European monitoring stations located Poland. occurrence several (e.g., glyceric tartronic tartaric OSs) field suggests that could contribute formation.

Language: Английский

Citations

0
Flame-Free Candles Are Not Pollution-Free: Scented Wax Melts as a Significant Source of Atmospheric Nanoparticles DOI Creative Commons
Satya S. Patra, Jinglin Jiang, Jianghui Liu

et al.

Environmental Science & Technology Letters, Journal Year: 2025, Volume and Issue: 12(2), P. 175 - 182

Published: Feb. 3, 2025

Scented wax melts are being popularized as a safer, nontoxic alternative to traditional candles and incense for indoor aromatherapy. We performed field measurements in residential test house investigate atmospheric nanoparticle formation from scented melt use. employed high-resolution particle size magnifier-scanning mobility sizer (PSMPS) proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) real-time monitoring of distributions terpene mixing ratios, respectively. Our findings reveal that terpenes released react with ozone (O3) initiate new (NPF) events, resulting significant concentrations (>106 cm–3) comparable those emitted by combustion-based candles, gas stoves, diesel engines, natural engines. show melt-initiated NPF events can result respiratory exposures, tract deposited dose rates similar determined sources. results challenge the perception safer aromatherapy, highlighting need further research on toxicological properties newly formed nanoparticles better understand their environmental health implications.

Language: Английский

Citations

0
Ppb-Level Self-Calibrating Ozone Detection Using a T-Type Multipass Enhanced Photoacoustic Sensor with a 9.46 μm Quantum Cascade Laser DOI Creative Commons
Yuxuan Wu, Pei-Ling Luo

Analytical Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 3, 2025

A sensitive, real-time, and accurate ozone (O3) sensor system is developed based on the combination of multipass enhanced photoacoustic (MPPA) direct absorption spectroscopy with a mid-infrared quantum cascade laser (QCL). The QCL an emission wavelength 9.46 μm was used to probe O3 lines without interference from water carbon dioxide in flowing mixtures. MPPA constructed T-type cell composed vertical cylinder horizontal cavity which were designed as acoustic resonator for enhancement, respectively. By periodically on–off switching modulation wavelength, rapidly switched measurements PA spectra can be achieved real-time calibrations second harmonic (2f) signals absorbance O3. Moreover, detection limit 6 ppb at average time 300 s achieved, short response 16 also obtained flow mixtures rate 50 sccm. This work provides reliable method capabilities parts-per-billion-level sensitivity on-site concentration calibration, thus holding promise situ monitoring under various environments.

Language: Английский

Citations

0
Gas-to-Particle Partitioning of Products from Ozonolysis of Δ3-Carene and the Effect of Temperature and Relative Humidity DOI Creative Commons
Linjie Li, Ditte Thomsen, Cheng Wu

et al.

The Journal of Physical Chemistry A, Journal Year: 2024, Volume and Issue: 128(5), P. 918 - 928

Published: Jan. 31, 2024

Formation of oxidized products from Δ3-carene (C10H16) ozonolysis and their gas-to-particle partitioning at three temperatures (0, 10, 20 °C) under dry conditions (<2% RH) also 10 °C humid (78% were studied using a time-of-flight chemical ionization mass spectrometer (ToF-CIMS) combined with filter inlet for gases aerosols (FIGAERO). The detected by the FIGAERO-ToF-CIMS dominated semivolatile organic compounds (SVOCs). main effect increasing temperature or RH on product distribution was an increase in fragmentation monomer (from C10 to C7 compounds), potentially via alkoxy scission losing C3 group. equilibrium coefficient estimated according theory shows that measured SVOC distribute more into SOA phase as decreases 0 most increases <2 78%. dependency saturation vapor pressure (above assumed liquid state), derived method, allows direct way obtain enthalpy vaporization species without accessibility authentic standards pure substances. This method can provide physical properties, beneficial for, e.g., atmospheric modeling, complex multifunctional oxidation products.

Language: Английский

Citations

2
Formation and temperature dependence of highly oxygenated organic molecules (HOMs) from Δ3-carene ozonolysis DOI Creative Commons
Yuanyuan Luo, Ditte Thomsen, Emil Mark Iversen

et al.

Atmospheric chemistry and physics, Journal Year: 2024, Volume and Issue: 24(16), P. 9459 - 9473

Published: Aug. 29, 2024

Abstract. Δ3-carene is a prominent monoterpene in the atmosphere, contributing significantly to secondary organic aerosol (SOA) formation. However, knowledge about oxidation pathways, particularly regarding their ability form highly oxygenated molecules (HOMs), still limited. In this study, we present HOM measurements during ozonolysis under various conditions two simulation chambers. We identified numerous HOMs (monomers: C7−10H10−18O6−14; dimers: C17−20H24−34O6−18) using chemical ionization mass spectrometer (CIMS). yielded higher concentrations than α-pinene, with distinct distribution, indicating differences formation pathways. All signals decreased considerably at lower temperatures, reducing estimated molar yield from ∼ 3 % 20 °C 0.5 0 °C. Interestingly, temperature change altered increasing observed dimer-to-monomer ratios roughly 0.8 1.5 monomers six or seven O atoms condensed more efficiently onto particles colder while nine and all dimers irreversibly even Using gas- particle-phase chemistry kinetic multilayer model ADCHAM, were also able reproduce experimentally composition, yields, dependence.

Language: Английский

Citations

2
Rapid Nucleation and Growth of Indoor Atmospheric Nanocluster Aerosol during the Use of Scented Volatile Chemical Products in Residential Buildings DOI Creative Commons
Satya S. Patra, Jianghui Liu, Jinglin Jiang

et al.

ACS ES&T Air, Journal Year: 2024, Volume and Issue: 1(10), P. 1276 - 1293

Published: Sept. 24, 2024

Scented volatile chemical products (sVCPs) are frequently used indoors. We conducted field measurements in a residential building to investigate new particle formation (NPF) from sVCP emissions. State-of-the-art instrumentation was for real-time monitoring of indoor atmospheric nanocluster aerosol (NCA; 1-3 nm particles) size distributions and terpene mixing ratios. integrated our NCA with comprehensive material balance model analyze sVCP-nucleated dynamics. Our results reveal that sVCPs significantly increase ratios (10-1,000 ppb), exceeding those outdoor forested environments. The emitted terpenes react O

Language: Английский

Citations

1
Spatiotemporal Variations and Driving Factor Analysis of Aerosol Optical Depth in Terrestrial Ecosystems in Northern Xinjiang from 2001 to 2023 DOI Creative Commons
Zequn Xiang, Hongqi Wu,

Yanmin Fan

et al.

Atmosphere, Journal Year: 2024, Volume and Issue: 15(11), P. 1302 - 1302

Published: Oct. 29, 2024

Investigating the spatiotemporal variations in Aerosol Optical Depth (AOD) terrestrial ecosystems and their driving factors is significant for deepening our understanding of relationship between ecosystem types aerosols. This study utilized 1 km resolution AOD data from Moderate Resolution Imaging Spectroradiometer (MODIS) Mann–Kendall (M-K) trend test to analyze seven Northern Xinjiang 2001 2023. The geographic detector model was employed investigate effects factors, including gross domestic product, population density, specific humidity, precipitation, temperature, wind speed, soil moisture, elevation, on distribution ecosystems. results indicate that over past 23 years, wetlands had highest annual average values, followed by settlements, farmlands, deserts, grasslands, others, forests, respectively. Furthermore, values decrease with increasing elevation. mean generally shows a fluctuating upward trend. M-K proportion area an settlement (92.17%), while decreasing forest (21.78%). On seasonal scale, grassland, settlement, farmland, forest, wetland exhibit peak spring winter, whereas desert other only show peaks spring. Different different sensitivities factors. Grassland are primarily influenced temperature altitude, most affected speed humidity. Farmlands mainly significantly impacted density predominantly humidity altitude. paper serves as reference targeted air pollution prevention regional ecological environmental protection.

Language: Английский

Citations

0
Developments at the AURA atmospheric simulation chamber to characterize chamber volume, air mixing, and charging DOI Creative Commons
Emil Mark Iversen, Merete Bilde, H. B. Pedersen

et al.

Aerosol Science and Technology, Journal Year: 2024, Volume and Issue: unknown, P. 1 - 23

Published: Dec. 10, 2024

We describe three developments at the AURA atmospheric simulation chamber (made of Teflon and with a volume ∼5 m3) aimed an improved understanding physical conditions to facilitate better basis for comparisons between experimental data results from numerical models. First, we demonstrate how can be monitored by observing position wall using fixed laser distance sensors. The absolute calibration is obtained through measurement relative humidity in during controlled dilution experiment. Second, direct measurement, characterize occurrence, magnitude (∼0 – 80 kV/m), decay time (∼10 20 h) static electric fields inside after charging. Further, confirm directly that significantly discharged kept steady mode charging addition ion fans enclosure where suspended. Third, improve air mixing capabilities adding two allows efficient within few minutes. effect field rate measurements particle loss injected polydisperse ammonium sulfate particles.

Language: Английский

Citations

0