[en] Mordenite is a zeolite mineral that processes a large ratio of silicon to aluminum and a large ion-exchange ability. These excellent characteristics provide thermal stability and nuclide sorption capability. A modified two-stage Freundlich sorption model is proposed based on the major factors of temperature, pH value and nuclide concentration that influence the sorption behavior of mordenite. The dominant sorption mechanism of mordenite is an ion-exchange reaction, while physical adsorption plays a minor role. (orig.)