Influence of the support base on the sorption of Co(II) with mixed solvents

Theonyltrifluoroacetone (TTA) mixed with trioctyl phosphine oxide (TOPO) have been supported on Amberlite XAD-4, silica gel and wood powder. The resulting resins have been used to study the sorption of cobalt(II) from acetate buffer and their sorption capacities were determined and were found to be 12.38, 11.61 and 6.51 mg g−1 for TTA + TOPO/Amberlite XAD4, TTA + TOPO/silica gel and TTA + TOPO/wood, respectively. The experimental results showed that the sorption of Co(II) increases with its initial concentration. The results can be fitted by Freundlich isotherm in the studied cobalt concentration range [10−4-10−3 M] and 1/n values are 1.07, 1.17 and 1.73 for Amberlite XAD4, silica gel and wood powder, respectively. The sorption of Co(II) onto the prepared resins was found to follow the pseudo-second order model and the sorption rate have the values 8.79 × 10−3, 10 × 10−3 and 16 × 10−3 g mg−1 min−1 for Amberlite XAD4, silica gel and wood powder, respectively. Thermodynamic parameters have also been calculated for the three systems and sorption process was found to be spontaneous and endothermic one.