Study of adsorption behavior of cesium and strontium ions with banana fiber adsorbent

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. (author)