UO22-ZEOLITE( SORPTION IN NATURAL MEXICAN ERIONITE AND Y)

The use of Y zeolite and erionite to remove UO2(2+) ions from aqueous solutions has been investigated. The effect of temperature, the concen tration of UO2(2+) uptake, the diffusion coefficients, and the ion-exc hange isotherms were also studied. X-ray diffraction, thermal analyses , and transmission electron microscopy were used to characterize the s olids. The UO2(2+) content was determined by neutron activation analys is. The diffusion coefficients are not clearly affected by temperature or concentration. They definitely depend on the structure of each zeo lite. The UO2(2+) exchange capacities were 0.2037 and 0.7345 meq UO2(2 +)/g for erionite and Y zeolite, respectively. It was found that UO2(2 +) is exchanged with the cations of the large cavity in Y zeolite. In the case of erionite, UO2(2+) is exchanged with the cations localized in sites where the charge densities are very high.