Adsorption of ytterbium(III) ions on ivy leaves marc: isotherm, kinetic and thermodynamic studies

This study evaluates the performance of ivy leaves marc (ILM) in adsorbing ¹⁶⁹Yb(III) ions. Optimal adsorption occurred at a pH of 4 ± 0.2, a contact time of 24h, ¹⁶⁹Yb(III) concentration of 200mg/L, and a temperature of 298K. Kinetic analysis indicated that the adsorption process followed a pseudo-second-order model. Langmuir isotherm model best described the adsorption process, with a maximum capacity of 34.736mg/g. Thermodynamic analysis revealed that the adsorption process was spontaneous and endothermic. FTIR and SEM analysis of ILM before and after adsorption indicates that the adsorption process is due to the ion exchange mechanism.