The application of moment analysis to the dynamic adsorption of radon by activated carbon

The adsorption of radon by activated carbon has received a great deal of attention within the academic press because of the importance of determining the radon concentration in the living environment. The deposition of energy from 222Rn decay and the daughter products of 222Rn is considered significant probable cause agent for lung cancer in the general population. Therefore, study of the adsorption by activated carbon has focused on the ability to determine radon concentrations under static conditions. The adsorption of radon under dynamic conditions, from moving air, has not been studied adequately to determine the underlying properties associated with this phenomenon. No method of determining the properties associated with dynamic has been developed. This research has provided a method to accurately determine the attributes that control radon adsorption from moving air at two different temperatures. The characteristics of several common activated carbons were determined and correlated to current theories. Changes in carrier gas velocity were shown to affect the mass transfer characteristics which are represented by the van Deemter equation used in gas chromatography. The methodology can be used to determine specific parameters of gas adsorption from the experimental data and include; (1) the coefficient for axial dispersion (2) the tortuosity factor, and (3) the intraparticle diffusion coefficient. These parameters affect changes in the number of theoretical plates and the height equivalent of a theoretical plate which are related to interparticle and intraparticle diffusion along with resistance to mass transfer.