Comparison of Radon Adsorption on Hematite and Charcoal Activated Powder in Air

: Adsorption of radon in the air was investigated on hematite, α -Fe 2 O 3 , and charcoal activated powder. Hematite had almost doubled efficiency in comparison to charcoal activated powder in the same experimental conditions but over a significantly longer per iod. Adsorption isotherms revealed a typical Langmuir shape on hematite and almost linear on activated charcoal. Linear models of Langmuir, Freundlich and Dubinin-Radushkevich isotherms showed that radon adsorption on both adsorbents is a favourable chemical process, with stronger interactions on hematite, that takes place forming a monolayer of ads orbed radon. The kinetic analysis confirmed forming of a monolayer on both adsorbents and two rate-controlling steps during radon adsorption on hematite, instead of one on activated charcoal, which could be considered as a reason of slower rate of process on hematite .