A theoretical model for {sup 222}Rn adsorption on activated charcoal canisters in humid air based on Polanyi`s potential theory
- Dept. of Energy, New York, NY (United States)
Water vapor interferes with adsorption {sup 222}Rn gas by passive activated charcoal devices used to estimate indoor air concentrations. The {sup 222}Rn adsorption coefficient is the fundamental parameter characterizing charcoal`s ability to adsorb {sup 222}Rn. The Dubinin-Radushkevich equation, based on Polanyi`s potential theory, was modified to include two terms quantifying the effect of both water vapor and sampling time on the {sup 222}Rn adsorption coefficient of passive charcoal devices. A single equation was derived that quantities the {sup 222}Rn adsorption coefficients at any temperature, humidity and exposure time using six experimentally determined physical constants that are unique for a particular passive charcoal device. The theoretical model was verified with published experimental data, and it showed a good correlation between theory and experiment. The model proved to be consistent with experimental data, provided that the amount of water vapor adsorbed by the charcoal device during sampling remains below a critical level, termed the breakpoint. 44 refs., 5 figs., 2 tabs.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 255119
- Journal Information:
- Health Physics, Vol. 68, Issue 3; Other Information: PBD: Mar 1995
- Country of Publication:
- United States
- Language:
- English
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