Effects of Zeolitic Parameters and Irradiation on the Retention Properties of Silver Zeolites Exposed to Molecular Iodine

We have investigated the iodine retention behavior of silver zeolite sorbents under a variety of conditions. First, a preliminary study was achieved for the liquid phase in order to determine (i) the main kinetic and thermodynamic characteristics pertaining to the adsorption behavior and (ii) the influence of some zeolitic parameters (nature of the framework, silver content, preparation method, etc.) on the adsorption capacities. Thanks to the online monitoring of gas phase 12 concentrations by UV vis spectroscopy, the iodine dynamic adsorption/desorption behavior of some selected sorbents was then studied at 100 degrees C. It was found that faujasite sorbents with silver content higher than 20 wt % could maintain a high working capacity (up to 330 mg/g) and present a high ability for irreversible trapping. Finally, the stability of trapped iodine species was evidenced using additional tests performed at 120 degrees C in the presence of irradiation and humidity.