Sorption mechanism of Cs+, Co2+ and Eu3+ ions onto EGIB sorbent

The sorption of Cs+, Co2+ and Eu3+ ions onto polyacylamide cerium titanate (EGIB) sorbent has been investigated at different reaction temperatures(30, 40, 50 and 60°C 1±°C). The sorption kinetics of these ions onto EGIB sorbent follows the pseudo-first-order rate equation. The sorption capacity was found to decrease as the reaction temperature increases. The sorption data were subjected to different sorption isotherms and the results verified that Freundlich isotherm is the best model to be applied; the values of 1/n were found to be 0.58, 0.45 and 0.38 for sorption of Cs+, Co2+ and Eu3+ ions, respectively, while, Cm values were 1.15, 2.75 and 1.82 mmol/g for the same ions at 30°C ±1°C. Negative values of ΔH for the uptake process on EGIB reflects the exothermic nature of the process. The calculated ΔH values were −18.23, −29.17 and −26.70 kJ/mol for Cs+, Co2+ and Eu3+ ions, respectively.