Determination of adsorption characteristics for different Cs selective ion-exchangers

Cesium-137 is often used for industrial and medical gamma sources. These could consist of Cs-137 which is adsorbed on inorganic or organic ion-exchangers, preferably vitrified to form a fixed source. Kd values of the five ion-exchangers for Cs (using Cs-137 as a tracer) were determined which reduced the further investigations (capacity and exchange rate) to three ion-exchangers. The ion-exchangers investigated are, according to the literature, all selective for Cs and therefore viewed as suited for these specific applications. Ion-exchangers investigated were Gelwhite L, Clinoptilolite, Chabazite, Cabsorb (all inorganic) and Resorcinol formaldehyde (organic resin). Similar data recently published by Zhang et al., for the ion-exchanger ZMPP (zirconyl molybdo pyrophosphate) was used as a bench. mark to compare the recorded results with. Results of the Kd experiments (batch method, contact time is 24 h) showed that at initial ph 1 to 4, the Chabazite and clinoptilolite performed the best. Ph >9, the RF resin and Cabsorb had the higher Kd values, with RF resin 7 times higher than Chabazite. This correlate with literature results for the RF resin. The capacity experiments (batch method and column method) showed that the RF resin has the highest capacity for Cs