Industrial & Engineering Chemistry Research, Vol.44, No.12, 4221-4226, 2005
Adsorption behaviors of Pt(II) and Pd(II) on collagen fiber immobilized bayberry tannin
It was found that the collagen fiber immobilized bayberry tannin exhibited high adsorption capacity to Pt(II) and Pd(II). The adsorption isotherms of Pt(II) and Pd(II) could be well described by the Langmuir equation, and their adsorption capacities increased with the rise of temperature. The adsorption kinetics investigations indicated that the adsorption rate of Pt(II) and Pd(II) on the immobilized bayberry tannin could be well described by the pseudo-second-order rate model, and the adsorption capacities calculated by the pseudo-second-order rate model were close to those determined by actual measurement. The adsorption column could be easily regenerated by dilute HCl solution after adsorption of Pd(II), but it was somewhat difficult to regenerate the adsorption column after adsorption of Pt(II). The influence of pH value on the adsorption of Pd(II) and Pt(II) was not significant, and the immobilized bayberry tannin kept high adsorption capacity for these two precious metal ions even at acidic pH. In consideration of this fact, the studies on selective adsorption of Pt(II) and Pd(II) from the mixture solution containing Fe(III), Cu(II), Ni(II), and Zn(II) were carried out by using immobilized bayberry tannin. The experimental results indicated that the adsorption selectivity of the immobilized bayberry tannin to Pt(II) and Pd(II) was remarkable at pH 2.0.