Record Display for the EPA National Library Catalog


Main Title Sorption and Reemission of Formaldehyde by Gypsum Wallboard.
Author Chang, J. C. S. ;
CORP Author Environmental Protection Agency, Research Triangle Park, NC. Air and Energy Engineering Research Lab.
Publisher 1993
Year Published 1993
Report Number EPA/600/A-93/078;
Stock Number PB93-180917
Additional Subjects Formaldehyde ; Indoor air pollution ; Sorption ; Desorption ; Mathematical models ; Mass transfer ; Wallboard ; Construction materials ; Buildings ; Gypsum ; Insulation ; Study estimates ; Comparison ;
Library Call Number Additional Info Location Last
NTIS  PB93-180917 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 25p
The paper gives results of an analysis of the sorption and desorption of formaldehyde by unpainted wallboard, using a mass transfer model based on the Langmuir sorption isotherm. The sorption and desorption rate constants are determined by short-term experimental data. Long-term sorption and desorption curves are developed by the mass transfer model without any adjustable parameters. Compared with other empirically developed models, the mass transfer model has more extensive applicability and provides an elucidation of the sorption and desorption mechanism that empirical models cannot. The mass transfer model is also more feasible and accurate than empirical models for applications such as scale-up and exposure assessment. For a typical indoor environment, the model predicts that gypsum wallboard is a much stronger sink for formaldehyde than for other indoor air pollutants such as tetrachloroethylene and ethylbenzene. The strong sink effects are reflected by the high equilibrium capacity and slow decay of the desorption curve.