Influence of Ammonia and Carbon Dioxide on the Sorption of a Basic Organic Pollutant to Carpet and Latex-Painted Gypsum Board
Sorptive interactions with indoor surfaces strongly influence indoor exposure to organic pollutants. Adsorption itself may be influenced by indoor levels of common indoor gases such as CO2, NH3, and H2O. We quantified sorption characteristics of trimethylamine (TMA) on carpet and painted wallboard, while challenging the surface with gas-phase CO2, NH3 and H2O. We show that the capacity of the carpet to sorb TMA, doubles when the CO2 mixing ratio is increased from 0 to 1000 ppm CO2 at 90% relative humidity. In contrast, NH3 decreases the surface capacity of both carpet and latex paint. Sorption of TMA to these indoor materials is primarily caused by interactions at one or more interfaces. Dissolution of TMA and aqueous acid−base chemistry appear to also contribute to the overall sorptive capacity of carpet at high relative humidity. The reduction in the distribution coefficient, ke, in the presence of NH3 is explained by competition between TMA and NH3 molecules for sites on the substrates at low-to-medium relative humidity conditions.
M. Ongwandee and G. Morrison, "Influence of Ammonia and Carbon Dioxide on the Sorption of a Basic Organic Pollutant to Carpet and Latex-Painted Gypsum Board," Environmental Science and Technology, American Chemical Society (ACS), Jun 2008.
The definitive version is available at http://dx.doi.org/10.1021%2Fes071935j
Civil, Architectural and Environmental Engineering
National Science Foundation (U.S.)
University of Missouri Research Board
Keywords and Phrases
Indoor Surfaces; Organic Pollutants; Sorptive Interactions
Article - Journal
© 2008 American Chemical Society (ACS), All rights reserved.