Air Pollution: Photooxidation of Aromatic Hydrocarbons

Altshuller, A. P.; Cohen, I. R.; Sleva, S.; Kopczynski, Stanley L.

doi:10.1126/science.138.3538.442

Cited by 27 publications

(29 citation statements)

References 3 publications

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“…As in the ethylenenitric oxide system, higher ratios occurred at the lower reactant concentrations and lower ratios of propylene to nitric oxide. These ratios are likely t o be minimum values (Altshuller and Cohen, 1964). Consequently, the present results support the previous work in that they indicate the presence of chains of appreciable length, particularly early in the reactions.…”

Section: Resultssupporting

confidence: 91%

“…Reaction 11 also can be used to explain the inhibition of the over-all reactions by excess nitric oxide. The possible importance of this reaction and related reactions was discussed previously by Altshuller and Cohen (1964) and by Tuesday (1961), Stransz andGunning (1964) also discussed the importance of H N O in the photolysis of formaldehyde with nitric oxide. At high concentrations of reactant, these investigators measured nitrogen and nitrous oxide as products.…”

Section: (7)mentioning

confidence: 92%

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Chemical aspects of the photooxidation of the propylene-nitrogen oxide system

Altshuller¹,

Kopczynski²,

Lonneman³

et al. 1967

Environ. Sci. Technol.

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The photooxidation of part-per-million concentrations of propylene in the presence of similar concentrations of nitric oxide has been investigated. The product yields were measured over a wide range of reactant concentrations and reactant ratios. Series of experiments were carried out with varying light intensities, with both static and dynamic flow conditions. The products measured by colorimetric, gas chromatographic, and various monitoring instruments included nitrogen dioxide, oxidant (ozone and other oxidizing agents), formaldehyde, acetaldehyde, carbon monoxide, peroxyacetyl nitrate, and methyl nitrate. The mechanism of the reactions involved is considered, including stoichiometry and the role of free radical intermediates. Carbon and nitrogen balances are computed, and difficulties in obtaining balances are considered.he photooxidation of various olefin-nitrogen oxide T systems has been studied (Altshuller and Bufalini, 1965;Leighton, 1961 ;Wayne, 1962). Much of this previous work is limited, however, by use of reactant concentrations well above atmospheric levels and by measurements of only a limited number of products over a narrow range of reactant cancentrations. Furthermore, measurements of eye irritation and plant damage often have not been obtained along with the chemical or physical results.Although it is not possible to represent fully all of the diverse effects associated with photochemical air pollution by studies of a single hydrocarbon, propylene was chosen as a representative reactive hydrocarbon. The propylene-nitrogen oxide system when irradiated reacts readily t o produce oxidant, formaldehyde, acetsldehyde, carbon monoxide, peroxyacetyl nitrate (PAN), and methyl nitrate and causes 070ne and PAN-type plant damage and eye irritation. Thus, major "smog" manifestations can be reproduced, although not necessarily at the intensities experienced in the ambient atmosphere.This paper reports the chemical and physical measurements of the photooxidation of propylene-nitrogen oxide over a range of reactant concentrations, a t several light intensity evels, and under static or dynamic flow conditions. Biological indicator measurements will be reported in another paper. ExperimentalThe propylene concentrations used included 0.25, 0.5, 1, 2, and 3 p.p.m. by volume, while the nitric oxide concentrations included0.125,0.20,0.25,0.50,0.6,0.7,0.75,1.0, 1.25, 1.50,2, 3, and 4 p.p.m. by volume. Irradiations also were conducted with 1, 2, or 3 p.p.m. of propylene in the chamber. but with only the background nitric oxide concentrations of 0.02 to 0.04 p.p.m normally present in the dilution air. The molar ratio3 of propylene to nitric oxide were varied from about 100 to 1 to 8.

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Section: Resultssupporting

confidence: 91%

Section: (7)mentioning

confidence: 92%

Chemical aspects of the photooxidation of the propylene-nitrogen oxide system

Altshuller¹,

Kopczynski²,

Lonneman³

et al. 1967

Environ. Sci. Technol.

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“…Photolysis of aldehydes can be a major source of hydroxyl radicals via reaction with NO 2 during the day (Possanzini et al 2002). Xylenes also participate in ancillary photo-oxidation reactions including the conversion of nitric oxide to nitrogen dioxide, with m-xylene being the most reactive isomer (Altshuller et al 1962). …”

Section: Photochemical Reactivity Of Vocs Towards Oh Radicalmentioning

confidence: 98%

Mixing ratios of carbonyls and BTEX in ambient air of Kolkata, India and their associated health risk

Dutta

Som

Chatterjee

et al. 2008

Environ Monit Assess

106

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Mixing ratios of 15 carbonyls and BTEX (benzene, toluene, ethyl benzene, xylenes) were measured for the first time in ambient air of Kolkata, India at three sites from March to June 2006 and their photochemical reactivity was evaluated. Day and nighttime samples were collected on weekly basis. Formaldehyde was the most abundant carbonyl (mean concentration ranging between 14.07 microg m(-3) to 26.12 microg m(-3) over the three sites) followed by acetaldehyde (7.60-18.67 microg m(-3)) and acetone (4.43-10.34 microg m(-3)). Among the high molecular weight aldehydes, nonanal showed the highest concentration. Among the mono-aromatic VOCs, mean concentration of toluene (27.65-103.31 microg m(-3)) was maximum, closely followed by benzene (24.97-79.18 microg m(-3)). Mean formaldehyde to acetaldehyde (1.4) and acetaldehyde to propanal ratios (5.0) were typical of urban air. Based on their photochemical reactivity towards OH. radical, the concentrations of the VOCs were scaled to formaldehyde equivalent, which showed that the high molecular weight carbonyls and xylenes contribute significantly to the total OH-reactive mass of the VOCs. Due to the toxic effect of the VOCs studied, an assessment for both cancer risk and non-cancer hazard due to exposure to the population were calculated. Integrated life time cancer risk (ILTCR) due to four carcinogens (benzene, ethyl benzene, formaldehyde and acetaldehyde) and non-cancer hazard index for the VOCs at their prevailing level were estimated to be 1.42E-04 and 5.6 respectively.

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“…Good carbon balances have been reported for irradiated systems in which the hydrocarbons were ethylene (Altshuller and Cohen, 1964), propylene (Altshuller et al, 1967), and 1-butene and trans-2-butene (Schuck and Doyle, 1959;Tuesday, 1961). Often, however, only gas-phase organic nitrogen products are considered; when surface-adsorbed products are analyzed, the nitrogen balances are greatly improved.…”

mentioning

confidence: 97%

Nitric acid and the nitrogen balance of irradiated hydrocarbons in the presence of oxides of nitrogen

Bufalini¹

1971

Environ. Sci. Technol.

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This restricts the sample size, resulting in a lowered effective sensitivity. An alternate technique could be the use of glacial HOAc as the extraction solvent. If the material were dissolved directly into the acid, the reagent concentration could be adjusted accordingly, and considerable sensitivity could be gained. Because the Br determination can be accomplished in the presence of large excesses of C1, this method, coupled with a C1 analysis technique, can be used for measuring Cl/Br ratios. Acknowledgment volume air filter samples. Literature Cited

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Air Pollution: Photooxidation of Aromatic Hydrocarbons

Cited by 27 publications

References 3 publications

Chemical aspects of the photooxidation of the propylene-nitrogen oxide system

Chemical aspects of the photooxidation of the propylene-nitrogen oxide system

Mixing ratios of carbonyls and BTEX in ambient air of Kolkata, India and their associated health risk

Nitric acid and the nitrogen balance of irradiated hydrocarbons in the presence of oxides of nitrogen

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