Temperature Dependence of Henry Constants of Radon Adsorption on Activated Carbons

Layer-by-layer gamma-spectrometric measurements of sorbent activity are used to calculate Henry constants and determine parameters of their temperature dependence for dynamic radon adsorption on activated carbon of grades AG-3, VSK-5, SKT-3, and NWC 12x40 in the 20 to 60°C range of temperatures. The logarithm of the Henry constant is a linear function of the inverse temperature throughout the considered range. The linearity of the obtained dependences allows the values of Henry constants to be calculated at temperatures outside the range studied experimentally. The isoteric heat of adsorption of radon on the activated carbon of the considered grades is calculated. The isosteric heat of adsorption grows monotonically upon raising the atomic number of the adsorbate in the series of inert gases Ar–Kr–Xe–Rn, indicating an increase in the sorption capacity of activated carbon in this series.