STP1205: Critical Evaluation of the Diffusion Hypothesis in the Theory of Porous Media Volatile Organic Compound (VOC) Sources and Sinks

    Dunn, JE
    Professor and chairman, and research assistant, University of Arkansas, Fayetteville, AR

    Chen, T
    Professor and chairman, and research assistant, University of Arkansas, Fayetteville, AR

    Pages: 17    Published: Jan 1993


    Abstract

    Recently, reports by both the U.S. Environmental Protection Agency (EPA) and a study committee of the Commission of the European Communities have alluded to diffusion mechanisms that may play a role in Volatile Organic Compound (VOC) interactions with indoor sinks. This paper proposes three alternative, diffusion-limited mathematical models to account for this interaction, using the linear isotherm model as a reference point. Their taxonomy is keyed to the nature of the vapor-sink interface. While the linear isotherm model gave an adequate description of data when a pillow-sink was challenged with ethylbenzene, a new single-parameter diffusion model gave a much improved description of data when the same pillow-sink was challenged with perchloroethylene. A hybrid, sorption/desorption, diffusion-limited model was the only plausible model when a carpet-sink was challenged with ethylbenzene. Some new computational aids, particularly intervalweighted least squares, are introduced in the context of model validation.

    Keywords:

    mathematical model, weighted least squares, linear isotherm, pillow, carpet, ethylbenzene, perchloroethylene, indoor air


    Paper ID: STP13100S

    Committee/Subcommittee: D22.05

    DOI: 10.1520/STP13100S


    CrossRef ASTM International is a member of CrossRef.