Tropospheric Chemistry of Aromatic Compounds Emitted from Anthropogenic Sources

Tropospheric Chemistry of Aromatic Compounds Emitted from Anthropogenic Sources 

Abstract The kinetics and mechanisms associated with the atmospheric photooxi- 

Arizona State Univeisity, Department of Civil Environmental Engineering and Department of Chemical Engineering, PO Box 875306, Tempe, AZ 85287-5306, USA E-mail jean.andino asu.edu 

Area de Qufmica CuSntica, Departamenfo de Quimica, Universidad Autonoma Metropolitana, Ixtapalapa, C.P. 09340, Mexico D.F., Mexico E-mail aimik xanum.uam.mx 1 Corresponding author. 

The primary tropospheric oxidants are OH, O3, and NO3, with OH and O3 reactions with hydrocarbons dominating primarily during daytime hours, and NO3 reactions dominating at night. Rate constants for the reactions of many different aromatic compounds with each of the aforementioned oxidants have been determined through laboratory experiments [16]. The rate constant data as well as atmospheric lifetimes for the reactions of toluene, m-xylene, p-xylene, m-ethyl-toluene, and 1,2,4-trimethylbenzene appear in Table 14.1. Only these particular aromatic compoimds will be discussed in this review paper, since much of the computational chemistry efforts have focused on these compounds. When considering typical atmospheric concentrations of the major atmospheric oxidants, OH, O3, and NO3 of 1.5 x 10, 7 x 10, and 4.8 x 10, molecules cm , respectively [17], combined with the rate constants, it is clear that the major atmospheric loss process for these selected aromatic compounds is reaction with the hydroxyl 

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