Highly effective removal of 22Na, 134Cs and 60Co from aqueous solutions by titanosilicate: a radiotracer study

Sorption of Na(I), Cs(I) and Co(II) radionuclides from aqueous solutions by titanosilicate have been investigated. The time dependent studies for metal ions showed relatively rapid sorption kinetics between 5 and 30 min to reach equilibrium. A batch adsorption model based on assumption of the pseudo-second-order mechanism was applied to predict the sorption rate, while the equilibrium capacity was calculated at different temperatures. The adsorption of different radionuclides onto titanosilicate was found to be favored at high ions concentrations and low temperature for Na+ and Co2+ while at high temperature for Cs+. Activation energy of adsorption was computed to be 2.35, 24.11 and 5.74 kJ/mol for adsorption of Na(I), Cs(I) and Co(II), respectively. The results revealed that the adsorption of Cs+ is the highest relative to Na+ and Co2+ at different conditions which may be attributed to its low hydration energy. Further, the equilibrium isotherm for the interested ions was analyzed and it was found to obey Frundlich equation.