Abstract: Cesium is one of the radioactive elements present in nuclear wastes resulting from industrial and research applications. This radionuclide is one of the major environmental hazards due to its high radioactivity and long half-life (about 30 years). In this study, Nickel Hexacyanoferrate-Analcim composite (NiHCF-Ana) was prepared and used as an adsorbent for the removal of cesium from aqueous solution. Response surface methodology was employed to study the effect of influential parameters, i.e. pH (2, 4, 6, 8 and 10), adsorbent dosage (0.04, 0.06, 0.08, 0.1 and 0.12 g/20 mL), initial cesium concentration (10, 25, 40, 55 and 70 mg/L) and temperature (15, 25, 35, 45 and 55 °C) on cesium removal efficiency. The optimization was performed with a total of 30 experimental runs based on the central composite design (CCD). According to the obtained results, cesium initial concentration and adsorbent dosage were found to be more influential than temperature and pH. Analysis of variance (ANOVA) showed a good agreement between theoretical analysis and experimental data. The validity of the model was verified by an experiment at the optimum conditions which resulted in 98.17% removal of cesium. Also the isotherm study showed a good agreement with the Langmuir isotherm model.
