Investigation and Modeling of Surface Sorption/Desorption Behavior of Volatile Organic Compounds for Indoor Air Quality Analysis
Titel:
Investigation and Modeling of Surface Sorption/Desorption Behavior of Volatile Organic Compounds for Indoor Air Quality Analysis
Auteur:
Bouhamra, W. S. Elkilani, A. S.
Verschenen in:
Environmental technology
Paginering:
Jaargang 20 (1999) nr. 5 pagina's 531-545
Jaar:
1999-05-01
Inhoud:
Volatile organic compound contents of 20 Kuwaiti houses were measured by pumped sampling versus time and 17 predominant compounds (namely, benzene, toluene, xylene, styrene, trimethylbenzene, butylbenzene, propylbenzene, dichloroethylene, trichloroethane, dichloropropane, dibromomethane, chloroform, tetrachloroethane, tetrachloroethylene, chlorotoluene, dichlorobenzene and fluorobenzene) have been identified. Other related factors, such as the outdoor concentrations, the surface areas of the walls and the furnishings, and the previously measured air exchange rates were incorporated in a transient mass balance model which also took into consideration the phenomenon surface sorption and the source emission. An integrated form of this model was used to analyze the experimental time-averaged concentration data. A plot of indoor concentration versus outdoor concentration for a specific VOC gave a straight line from which the removal rate by adsorption and the source emission were obtained. It was found that the data correlated satisfactorily if the surface area for sorption was estimated based not only on the surfaces of walls, ceiling and floor (an approach often used by other workers in previous studies) but also those of all components of interior, such as those of furniture. The surface sorption rate constants for each VOC under study were evaluated and they varied between 0.2 to 0.96 m hr-1 depending on the chemical nature of the VOCs. These results showed also that the removal rates of aliphatic and aromatic VOCs by adsorption increased if they were attached to halogen and alkyl groups respectively. On the other hand, relatively low removal rates were observed when unsaturated alkyl and phenyl groups were attached to a halogen.
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