Adsorption of La3+, Ce3+ from Aqueous Solutions by Bayberry Tannin Grafted Chitosan

Bayberry tannin grafted with chitosan (CS-BT) had been successfully prepared and their adsorption performance had been studied La3+, Ce3+ rare earth ions aqueous solutions. The as-prepared absorbents were characterized by Fourier transform infrared spectrometer and scanning electron microscopy. The result showed under optimal conditions [T=40 degrees C; C=2.0 g/L; pH=3.0 (La3+), pH=4.0 (Ce3+);] that the saturation adsorption capacities of CS-BT to La3+, Ce3+ were 58.42 mg/g, 800.08 mg/g, respectively, when [T=30 degrees C; C=1.0 g/L; pH=4.0 (La3+, Ce3+);] the difference of adsorption quantity between La3+ and Ce3+ reach up to 101.5 mg/g by using the absorbent (CS-BT). The adsorbent exhibited better adsorption capacity to Ce3+ than that of La3+. The CS-BT had high adsorption rate and could achieve basic saturated adsorption in about 5 min. It was found that the adsorption kinetics was well described by the adsorption isotherms followed Freundlich (La3+, Ce3+) adsorption model and the pseudo-second order kinetic model. The research indicated CS-BT could be used as the cheaper and friendly absorbent in enrichment and separation of RE3+ in aqueous solution.