Modeled Emission of Hydroxyl and Ozone Reactivity from Evaporation of Fragrance Mixtures

2021 ◽  
Author(s):  
James F. Hurley ◽  
Elizabeth Smiley ◽  
Gabriel Isaacman-VanWertz
Keyword(s):  
Ozone Reactivity

scholarly journals KINETICS OF OZONE REACTIONS WITH ADENINE AND CYTOSINE IN AQUEOUS SOLUTIONS

2020 ◽  
Vol 63 (10) ◽  
pp. 17-22
Author(s):  
Aigul A. Maksyutova ◽  
Elvina R. Khaynasova ◽  
Yuriy S. Zimin
Keyword(s):  
Aqueous Solutions ◽  
Rate Constants ◽  
Correlation Coefficients ◽  
Activation Parameters ◽  
Second Order ◽  
Order Kinetic ◽  
Temperature Dependences ◽  
Ozone Reactivity ◽  
Kinetics Of ◽  
Ozone Reactions

The ultraviolet spectroscopy method has been applied to study the kinetics of the ozone reactions with nitrogenous bases (NB), namely adenine and cytosine in aqueous solutions. At the first research stage, the range of NB working concentrations has been determined. It was found that linear dependences between optical densities and concentrations of nitrogenous bases aqueous solutions are quite reliable, with correlation coefficients r ≥ 0.998, are satisfied up to [NB] = 2.3 ∙ 10–4 mol/l. According to the Bouguer-Lambert-Beer law, adenine and cytosine extinction coefficients in aqueous solutions were determined and subsequently used to calculate their residual concentrations. At the next stage, the kinetics of nitrogenous bases ozonized oxidation was studied with equal initial concentrations of the starting substances ([NB]0 = [О3]0). The results revealed that the kinetic consumption curves of the starting reagents are fairly well linearized (r ≥ 0.996) in the second-order reaction equation coordinates. As found with the bubbling installation, 1 mol of the absorbed ozone falls on 1 mol of the used NB. Thus, the reactions of ozone with adenine and cytosine explicitly proceed according to the second-order kinetic laws (the first – according to О3 and the first – according to NB). The rate constants were calculated by the integral reaction equations, the values of which indicate a higher ozone reactivity in relation to nitrogen bases. The temperature dependences of the second-order rate constants was studied ranging 285-309 K, and the activation parameters (pre-exponential factors and activation energies) of the ozone reactions with adenine and cytosine in aqueous solutions were determined.

scholarly journals Forest-atmosphere exchange of ozone: sensitivity to very reactive biogenic VOC emissions and implications for in-canopy photochemistry

2011 ◽  
Vol 11 (15) ◽  
pp. 7875-7891 ◽  
Author(s):  
G. M. Wolfe ◽  
J. A. Thornton ◽  
M. McKay ◽  
A. H. Goldstein
Keyword(s):  
Vertical Mixing ◽  
Trace Gas ◽  
Reaction Products ◽  
Ozone Flux ◽  
Aerosol Mass ◽  
Ozone Sensitivity ◽  
Biogenic Voc ◽  
Volatile Organic ◽  
Urban Rural ◽  
Ozone Reactivity

Abstract. Understanding the fate of ozone within and above forested environments is vital to assessing the anthropogenic impact on ecosystems and air quality at the urban-rural interface. Observed forest-atmosphere exchange of ozone is often much faster than explicable by stomatal uptake alone, suggesting the presence of additional ozone sinks within the canopy. Using the Chemistry of Atmosphere-Forest Exchange (CAFE) model in conjunction with summer noontime observations from the 2007 Biosphere Effects on Aerosols and Photochemistry Experiment (BEARPEX-2007), we explore the viability and implications of the hypothesis that ozonolysis of very reactive but yet unidentified biogenic volatile organic compounds (BVOC) can influence the forest-atmosphere exchange of ozone. Non-stomatal processes typically generate 67 % of the observed ozone flux, but reactions of ozone with measured BVOC, including monoterpenes and sesquiterpenes, can account for only 2 % of this flux during the selected timeframe. By incorporating additional emissions and chemistry of a proxy for very reactive VOC (VRVOC) that undergo rapid ozonolysis, we demonstrate that an in-canopy chemical ozone sink of ~2 × 108 molec cm−3 s−1 can close the ozone flux budget. Even in such a case, the 65 min chemical lifetime of ozone is much longer than the canopy residence time of ~2 min, highlighting that chemistry can influence reactive trace gas exchange even when it is "slow" relative to vertical mixing. This level of VRVOC ozonolysis could enhance OH and RO2 production by as much as 1 pptv s−1 and substantially alter their respective vertical profiles depending on the actual product yields. Reaction products would also contribute significantly to the oxidized VOC budget and, by extension, secondary organic aerosol mass. Given the potentially significant ramifications of a chemical ozone flux for both in-canopy chemistry and estimates of ozone deposition, future efforts should focus on quantifying both ozone reactivity and non-stomatal (e.g. cuticular) deposition within the forest.

scholarly journals Photolysis, OH reactivity and ozone reactivity of a proxy for isoprene-derived hydroperoxyenals (HPALDs)

2012 ◽  
Vol 14 (20) ◽  
pp. 7276 ◽  
Author(s):  
Glenn M. Wolfe ◽  
John D. Crounse ◽  
Jonathan D. Parrish ◽  
Jason M. St. Clair ◽  
Melinda R. Beaver ◽  
...  
Keyword(s):  
Ozone Reactivity

Ozone Reactivity with Seawater Components

1979 ◽  
Vol 1 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Lynn Kosak-Channing ◽  
George R. Helz
Keyword(s):  
Ozone Reactivity

scholarly journals An instrument for in-situ measurement of total ozone reactivity

2019 ◽  
Author(s):  
Roberto Sommariva ◽  
Louisa J. Kramer ◽  
Leigh R. Crilley ◽  
Mohammed S. Alam ◽  
William J. Bloss
Keyword(s):  
Total Ozone ◽  
Diurnal Pattern ◽  
Aromatic Plants ◽  
Ambient Conditions ◽  
Mixing Ratios ◽  
Ozone Reactivity ◽  
Ambient Levels ◽  
Made In

Abstract. We present an instrument for the measurement of total ozone reactivity (RO3), i.e. the reciprocal of the chemical lifetime of ozone (O3) in the troposphere. The Total Ozone Reactivity System (TORS) was developed with the objective to study the role of biogenic organic compounds (BVOCs) as chemical sinks of tropospheric ozone. The instrument was extensively characterized and tested in the laboratory using individual compounds and small plants (lemonthyme, Thymus citriodorus) in a Teflon bag and proved able to measure reactivities corresponding to > 4.5 × 10−5 s−1, corresponding to 20 ppb of α-pinene or 150 ppb of isoprene in isolation – larger than typical ambient levels but consistent with levels commonly found in environmental chamber and enclosure experiments. The functionality of TORS was demonstrated in quasi-ambient conditions with a deployment in a horticultural glasshouse containing a range of aromatic plants. The measurements of total ozone reactivity made in the glasshouse showed a clear diurnal pattern, following the emissions of BVOCs, and is consistent with mixing ratios of tens ppb of monoterpenes and several ppb of sesquiterpenes.

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