Recent works on the synthesis of ion exchanger from unutilized resources, inorganic wastes, were introduced. Among them, application of alkali fusion on the process of zeolite synthesis from waste stone cake was focused. Silicate minerals with stable crystal structure, such as quartz and feldspar is difficult to be solved into the solution by hydrothermal treatment. By applying alkali fusion process, these minerals can be converted into amorphous gels to form zeolite crystals at low temperature (<100℃).

View full abstract

 Adsorption of cesium (Cs⁺) and strontium ions (Sr²⁺) was studied using banana fiber as adsorbent in an adsorption column. Adsorption was performed by pumping 100 ppb diluted Cs⁺, and 1000 ppb diluted Sr²⁺ solutions into the column at a flow rate of 30 cm³/min. Almost 100% of Cs⁺ and Sr²⁺ were adsorbed. These results show that BF can be employed to serve as a cartridge filter for ⁹⁰Sr, ¹³⁴Cs and ¹³⁷Cs. The breakthrough points of Cs⁺ and Sr²⁺ were about 100 cm³ and 3500 cm³ bed, respectively. Desorption of Cs⁺ and Sr²⁺ was carried out by 1.0 mol dm⁻³ nitric acid. A part of Sr²⁺ was desorbed; whereas, desorption of Cs⁺ was negligible. The results suggest that the adsorption reaction of monovalent Cs⁺ and divalent Sr²⁺ are different. The adsorption site of divalent Sr²⁺ can be considered as weak acid ion-exchange site and unknown adsorption site. The adsorption site of monovalent Cs⁺, however, can not be considered as weak acidity ion-exchange site.

View full abstract