scholarly journals Heterogeneous conversion of NO<sub>2</sub> on secondary organic aerosol surfaces: A possible source of nitrous acid (HONO) in the atmosphere?

2003 ◽  
Vol 3 (1) ◽  
pp. 597-613 ◽  
Author(s):  
R. Bröske ◽  
J. Kleffmann ◽  
P. Wiesen
Keyword(s):  
Nitrous Acid ◽  
Secondary Organic Aerosols ◽  
Organic Aerosols ◽  
Oh Radicals ◽  
Atmospheric Conditions ◽  
Flow Tube ◽  
Upper Limits ◽  
Uptake Coefficients ◽  
Heterogeneous Formation ◽  
Organic Particles

Abstract. The heterogeneous conversion of NO2 on different secondary organic aerosols (SOA) was investigated with the focus on a possible formation of nitrous acid (HONO). In one set of experiments different organic aerosols were produced in the reactions of O3 with α-pinene, limonene or catechol and OH radicals with toluene or limonene, respectively. The aerosols were sampled on filters and exposed to humidified NO2 mixtures under atmospheric conditions. The estimated upper limits for the uptake coefficients of NO2 and the reactive uptake coefficients NO2 →HONO are in the range of 10−6 and 10−7, respectively. The integrated HONO formation for 1 h reaction time was <1013 cm−2 geometrical surface and <1017 g−1 particle mass. In a second set of experiments the conversion of NO2 into HONO in the presence of organic particles was carried out in an aerosol flow tube under atmospheric conditions. In this case the aerosols were produced in the reaction of O3 with β-pinene, limonene or catechol, respectively. The upper limits for the reactive uptake coefficients NO2 \\rightarrow HONO were in the range of 7×10−7 −9×10−6. The results from the present study show that heterogeneous formation of nitrous acid on secondary organic aerosols (SOA) is unimportant for the atmosphere.

scholarly journals Heterogeneous conversion of NO<sub>2</sub> on secondary organic aerosol surfaces: A possible source of nitrous acid (HONO) in the atmosphere?

2003 ◽  
Vol 3 (3) ◽  
pp. 469-474 ◽  
Author(s):  
R. Bröske ◽  
J. Kleffmann ◽  
P. Wiesen
Keyword(s):  
Nitrous Acid ◽  
Secondary Organic Aerosols ◽  
Organic Aerosols ◽  
Oh Radicals ◽  
Atmospheric Conditions ◽  
Alpha Pinene ◽  
Upper Limits ◽  
Uptake Coefficients ◽  
Heterogeneous Formation ◽  
Organic Particles

Abstract. The heterogeneous conversion of NO2 on different secondary organic aerosols (SOA) was investigated with the focus on a possible formation of nitrous acid (HONO). In one set of experiments different organic aerosols were produced in the reactions of O3 with alpha-pinene, limonene or catechol and OH radicals with toluene or limonene, respectively. The aerosols were sampled on filters and exposed to humidified NO2  mixtures under atmospheric conditions. The estimated upper limits for the uptake coefficients of NO2  and the reactive uptake coefficients NO2  -> HONO are in the range of 10-6 and 10-7, respectively. The integrated HONO formation for 1 h reaction time was <1013 cm-2 geometrical surface and <1017 g-1 particle mass. In a second set of experiments the conversion of NO2 into HONO in the presence of organic particles was carried out in an aerosol flow tube under atmospheric conditions. In this case the aerosols were produced in the reaction of O3 with beta-pinene, limonene or catechol, respectively. The upper limits for the reactive uptake coefficients NO2 -> HONO were in the range of 7 x 10-7 - 9 x 10-6. The results from the present study show that heterogeneous formation of nitrous acid on secondary organic aerosols (SOA) is unimportant for the atmosphere.

scholarly journals Heterogeneous loss of OH on NaCl and NH<sub>4</sub>NO<sub>3</sub> at tropospheric temperatures

1996 ◽  
Vol 14 (6) ◽  
pp. 659-664 ◽  
Author(s):  
A. V. Ivanov ◽  
Y. M. Gershenzon ◽  
F. Gratpanche ◽  
P. Devolder ◽  
J.-P. Sawerysyn
Keyword(s):  
Temperature Dependence ◽  
Detection Method ◽  
Tropospheric Chemistry ◽  
Minor Role ◽  
Oh Radicals ◽  
Flow Tube ◽  
Temperature Range ◽  
Uptake Coefficients

Abstract. The uptake coefficients (Γ) for OH radicals on some dry salts of tropospheric interest (NaCl and NH4NO3) have been investigated as a function of temperature using the flow tube technique combined with an EPR spectrometer as a detection method. The temperature dependence of Γ-values measured over the temperature range 245–340 K can be expressed in Arrhenius form: ΓOHNaCl=(1.2±0.7)×10–5exp[(1750±200)/T] and ΓOHNH4NO3=(1.4±0.5)×10–4exp[(1000±100)/T]. These Arrhenius expressions lead to very similar Γ-values (~4×10–3) for both salts studied at 300 K. It is shown that the heterogeneous OH sinks on solids aerosol play a very minor role in tropospheric chemistry in comparison with the homogeneous sinks.

scholarly journals Studying volatility from composition, dilution, and heating measurements of secondary organic aerosols formed during <i>α</i>-pinene ozonolysis

2018 ◽  
Vol 18 (8) ◽  
pp. 5455-5466 ◽  
Author(s):  
Kei Sato ◽  
Yuji Fujitani ◽  
Satoshi Inomata ◽  
Yu Morino ◽  
Kiyoshi Tanabe ◽  
...  
Keyword(s):  
Secondary Organic Aerosols ◽  
Yield Curve ◽  
Volume Fraction ◽  
Organic Aerosols ◽  
Accommodation Coefficient ◽  
Oh Radicals ◽  
Ionization Mass ◽  
Mass Accommodation Coefficient ◽  
Kinetic Inhibition ◽  
Photochemical Aging

Abstract. Traditional yield curve analysis shows that semi-volatile organic compounds are a major component of secondary organic aerosols (SOAs). We investigated the volatility distribution of SOAs from α-pinene ozonolysis using positive electrospray ionization mass analysis and dilution- and heat-induced evaporation measurements. Laboratory chamber experiments were conducted on α-pinene ozonolysis, in the presence and absence of OH scavengers. Among these, we identified not only semi-volatile products, but also less volatile highly oxygenated molecules (HOMs) and dimers. Ozonolysis products were further exposed to OH radicals to check the effects of photochemical aging. HOMs were also formed during OH-initiated photochemical aging. Most HOMs that formed from ozonolysis and photochemical aging had 10 or fewer carbons. SOA particle evaporation after instantaneous dilution was measured at  < 1 and  ∼ 40 % relative humidity. The volume fraction remaining of SOAs decreased with time and the equilibration timescale was determined to be 24–46 min for SOA evaporation. The experimental results of the equilibration timescale can be explained when the mass accommodation coefficient is assumed to be 0.1, suggesting that the existence of low-volatility materials in SOAs, kinetic inhibition, or some combined effect may affect the equilibration timescale measured in this study.

scholarly journals Reactive oxygen species formed in aqueous mixtures of secondary organic aerosols and mineral dust influencing cloud chemistry and public health in the Anthropocene

2017 ◽  
Vol 200 ◽  
pp. 251-270 ◽  
Author(s):  
Haijie Tong ◽  
Pascale S. J. Lakey ◽  
Andrea M. Arangio ◽  
Joanna Socorro ◽  
Christopher J. Kampf ◽  
...  
Keyword(s):  
Public Health ◽  
Reactive Oxygen Species ◽  
Secondary Organic Aerosols ◽  
Mineral Dust ◽  
Organic Aerosols ◽  
Reactive Oxygen ◽  
Oh Radicals ◽  
Oxygen Species ◽  
Aqueous Mixtures ◽  
Cloud Chemistry

Mineral dust and secondary organic aerosols (SOA) account for a major fraction of atmospheric particulate matter, affecting climate, air quality and public health. How mineral dust interacts with SOA to influence cloud chemistry and public health, however, is not well understood. Here, we investigated the formation of reactive oxygen species (ROS), which are key species of atmospheric and physiological chemistry, in aqueous mixtures of SOA and mineral dust by applying electron paramagnetic resonance (EPR) spectrometry in combination with a spin-trapping technique, liquid chromatography-tandem mass spectrometry (LC-MS/MS), and a kinetic model. We found that substantial amounts of ROS including OH, superoxide as well as carbon- and oxygen-centred organic radicals can be formed in aqueous mixtures of isoprene, α-pinene, naphthalene SOA and various kinds of mineral dust (ripidolite, montmorillonite, kaolinite, palygorskite, and Saharan dust). The molar yields of total radicals were ∼0.02–0.5% at 295 K, which showed higher values at 310 K, upon 254 nm UV exposure, and under low pH (<3) conditions. ROS formation can be explained by the decomposition of organic hydroperoxides, which are a prominent fraction of SOA, through interactions with water and Fenton-like reactions with dissolved transition metal ions. Our findings imply that the chemical reactivity and aging of SOA particles can be enhanced upon interaction with mineral dust in deliquesced particles or cloud/fog droplets. SOA decomposition could be comparably important to the classical Fenton reaction of H2O2 with Fe2+ and that SOA can be the main source of OH radicals in aqueous droplets at low concentrations of H2O2 and Fe2+. In the human respiratory tract, the inhalation and deposition of SOA and mineral dust can also lead to the release of ROS, which may contribute to oxidative stress and play an important role in the adverse health effects of atmospheric aerosols in the Anthropocene.

scholarly journals Light induced conversion of nitrogen dioxide into nitrous acid on submicron humic acid aerosol

2007 ◽  
Vol 7 (16) ◽  
pp. 4237-4248 ◽  
Author(s):  
K. Stemmler ◽  
M. Ndour ◽  
Y. Elshorbany ◽  
J. Kleffmann ◽  
B. D'Anna ◽  
...  
Keyword(s):  
Humic Acid ◽  
Relative Humidity ◽  
Nitrogen Dioxide ◽  
Nitrous Acid ◽  
Ambient Pressure ◽  
Urban Environments ◽  
Atmospheric Conditions ◽  
Rural And Urban ◽  
Humic Materials ◽  
Uptake Coefficients

Abstract. The interactions of aerosols consisting of humic acids with gaseous nitrogen dioxide (NO2) were investigated under different light conditions in aerosol flow tube experiments at ambient pressure and temperature. The results show that NO2 is converted on the humic acid aerosol into nitrous acid (HONO), which is released from the aerosol and can be detected in the gas phase at the reactor exit. The formation of HONO on the humic acid aerosol is strongly activated by light: In the dark, the HONO-formation was below the detection limit, but it was increasing with the intensity of the irradiation with visible light. Under simulated atmospheric conditions with respect to the actinic flux, relative humidity and NO2-concentration, reactive uptake coefficients γrxn for the NO2→HONO conversion on the aerosol between γrxn <10−7 (in the dark) and γrxn=6×10−6 were observed. The observed uptake coefficients decreased with increasing NO2-concentration in the range from 2.7 to 280 ppb and were dependent on the relative humidity (RH) with slightly reduced values at low humidity (<20% RH) and high humidity (>60% RH). The measured uptake coefficients for the NO2→HONO conversion are too low to explain the HONO-formation rates observed near the ground in rural and urban environments by the conversion of NO2→HONO on organic aerosol surfaces, even if one would assume that all aerosols consist of humic acid only. It is concluded that the processes leading to HONO formation on the Earth surface will have a much larger impact on the HONO-formation in the lowermost layer of the troposphere than humic materials potentially occurring in airborne particles.

scholarly journals Lower than expected volatility of secondary organic aerosols formed during α-pinene ozonolysis

2017 ◽  
Author(s):  
Kei Sato ◽  
Yuji Fujitani ◽  
Satoshi Inomata ◽  
Yu Morino ◽  
Kiyoshi Tanabe ◽  
...  
Keyword(s):  
Secondary Organic Aerosols ◽  
Yield Curve ◽  
Organic Aerosols ◽  
Curve Analysis ◽  
Oh Radicals ◽  
Ionization Mass ◽  
Mass Analysis ◽  
Volatile Products ◽  
Volatile Organic ◽  
Photochemical Aging

Abstract. Traditional yield curve analysis shows that semi-volatile organic compounds are a major component of secondary organic aerosols (SOAs). We investigated the volatility distribution of SOAs from α-pinene ozonolysis using positive electrospray ionization mass analysis and dilution- and heat-induced evaporation measurements. Laboratory chamber experiments were conducted on α-pinene ozonolysis, in the presence and absence of OH scavengers. Among these, we identified not only semi-volatile products, but also less volatile highly oxygenated molecules (HOMs) and dimers. Ozonolysis products were further exposed to OH radicals to check the effects of photochemical aging. HOMs were also formed during OH-initiated photochemical aging. Most HOMs that formed from ozonolysis and photochemical aging had ten or less carbons. SOA particle evaporation after instantaneous dilution was measured at

scholarly journals Light induced conversion of nitrogen dioxide into nitrous acid on submicron humic acid aerosol

2007 ◽  
Vol 7 (2) ◽  
pp. 4035-4064 ◽  
Author(s):  
K. Stemmler ◽  
M. Ammann ◽  
Y. Elshorbany ◽  
J. Kleffmann ◽  
M. Ndour ◽  
...  
Keyword(s):  
Humic Acid ◽  
Relative Humidity ◽  
Nitrogen Dioxide ◽  
Nitrous Acid ◽  
Ambient Pressure ◽  
Urban Environments ◽  
Atmospheric Conditions ◽  
Rural And Urban ◽  
Humic Materials ◽  
Uptake Coefficients

Abstract. The interactions of aerosols consisting of humic acids with gaseous nitrogen dioxide (NO2) were investigated under different light conditions in aerosol flow tube experiments at ambient pressure and temperature. The results show that NO2 is converted on the humic acid aerosol into nitrous acid (HONO), which is released from the aerosol and can be detected in the gas phase at the reactor exit. The formation of HONO on the humic acid aerosol is strongly activated by light: In the dark, the HONO-formation was below the detection limit, but it was increasing with the intensity of the irradiation with visible light. Under simulated atmospheric conditions with respect to the actinic flux, relative humidity and NO2-concentration, reactive uptake coefficients γrxn for the NO2→HONO conversion on the aerosol between γrxn <10−7 (in the dark) and γrxn = 6×10−6 were observed. The observed uptake coefficients decreased with increasing NO2-concentration in the range from 2.7 to 280 ppb and were dependent on the relative humidity (RH) with slightly reduced values at low humidity (<20% RH) and high humidity (>60% RH). The measured uptake coefficients for the NO2→HONO conversion are too low to explain the HONO-formation rates observed near the ground in rural and urban environments by the conversion of NO2→HONO on organic aerosol surfaces, even if one would assume that all aerosols consist of humic acid only. It is concluded that humic materials present on the Earth surface will have a much larger impact on the HONO-formation in the lowermost layer of the troposphere than humic materials potentially occurring in airborne particles.

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