The adsorption behaviors of Cr(VI) on collagen fiber immobilized bayberry tannin(IBT) , a new kind of adsorbent, were investigated. It was found that the adsorption capacity of Cr(VI) increased with the decrease of pH value. At the pH 2.0 and temperature of 303 K, the adsorption capacity of Cr(VI) on 0.100 g adsorbent was 78.5 mg·g-1in 100 ml of 100.0 mg Cr(VI)·L-1 solution, and decreased with the raise of temperature. The adsorption isotherms could be well described by the Freundlich equation. The adsorption kinetics investigations indicated that the adsorption rate of Cr(VI) on IBT could be well described by the pseudo-second-order rate model, and the adsorption capacities calculated by the pseudo-second-order rate model were closed to measurements. The adsorption mechanism investigations indicated that the adsorption of Cr(VI) on IBT was a redox process. It could be consisted of two reaction steps: firstly Cr(VI) being deoxidized to Cr(III), and then reduced Cr(III) combining with —COO— or the adjacent hydroxylphenyl groups in IBT.
