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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 2:13 |
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Conference: Bucharest University Faculty of Physics 2003 Meeting
Section: Atmosphere and Earth Science; Environment Protection
Title:
Study on photochemical model applied to the assessment of ozone concentrations in ambient air
Authors:
Silviu-Laurentiu Badea
Affiliation:
University of Bucharest, Faculty of Chemistry, Environment Chemistry
E-mail
Keywords:
Abstract:
The development of photochemical smog is dependent upon solar radiation, source emissions of hydrocarbons and nitrogen oxides, and atmospheric stability (for enhanced concentrations). Early in the morning, commuter traffic releases NO and hydrocarbons. At the same time, NO2 may decrease through because the sunlight can break it down to NO and O. The O is then free to react with O2 to form O3. Shortly thereafter, oxidized hydrocarbons react with NO to increase NO2 by midmorning. This reaction causes NO decreassing and O3 to build up, producing a midday peak in O3 and minimum in NO. Analyses of photochemical oxidants in the ambient air have revealed the presence of a number of phytotoxic compounds, including ozone (O3), peroxyacetyl nitrates (PANs), and nitrogen dioxide (NO2).
Ozone concentration depends on its precursors` concentration ( NOx, hydrocarbons). By using a photochemical model based on PSSA (Pseudo Steady State Approximation), we have calculated the ozone concentration in ambient air, depending on NO and NO2 concentration. The chart of the calculated ozone renders a similar form to the chart of the measured ozone. The study suggests new photochemical reactions that could take place into the atmosphere.
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