AN ALUMINUM PILLARED MONTMORILLONITE WITH FAST UPTAKE OF STRONTIUM AND CESIUM FROM AQUEOUS-SOLUTIONS

The uptake of Sr and Cs by 2 types of aluminum pillared layered clays (Al-PILC), a reference sample (AZA) and a specially tailored sample (F RAZA), were investigated. The AZA sample was prepared from air-dried p recursors and the FRAZA sample from freeze-dried precursors. X-ray dif fraction (XRD), pore and grain size measurements revealed that freeze- drying leads to a very fine-grained material with substantial mesoporo sity. In contrast, air-drying results in coarse grains and an essentia lly microporous material. Four different methods were tested for resto ring the cation exchange capacity (CEC) of the prepared PILCs. The mos t effective method proved to be exposing the material to ammonia fumes , then soaking it in a NaCl solution at pH = 10. Strontium and Cs kine tic experiments were carried out with PILCs after restoring their CEC by this method. The results revealed 1 fast uptake component in both m aterials but with different relaxation times for each PILC.