Adsorption Properties of Pr~(3+) and Nd~(3+) Using Silica Grafted with Larch Tannin

摘要

The new adsorption material was prepared by grafting the larch tannin onto aminated silica beads with the glutaraldehyde as the cross-linking agent. The adsorption properties of Pr~(3+) and Nd~(3+) on the new adsorbent material in aqueous solution were investigated. The results showed that the equilibrium adsorption capacities of this adsorbent to Pr~(3+), Nd~(3+) were 402.12mg/g, 305.43mg/g at 303K when the initial concentrations of each ions were 442.7mg/L, 432.6mg/L, respectively and the pH value was 5.5; the maximum adsorption quantities of each ions were 576.34mg/g, 497.02mg/g at 303K when the initial concentrations of each ions were 704.5mg/L, 721.0mg/L, respectively and the pH value was 5.5. The effect of pH value was significant to the equilibrium adsorption capacity, the optimum pH values of this material to Pr~(3+) and Nd~(3+) were both 5.5; while the effect of the temperature was not obvious to the equilibrium adsorption capacity. The adsorption thermodynamics meet Freundlich equation, and the adsorption kinetics data of this adsorbent to Pr~(3+), Nd~(3+) fitted with the pseudo-second-order rate equation dynamics model.