Preparation of cellulose acetate/zeolite composite fiber and its adsorption behavior for heavy metal ions in aqueous solution

Cellulose acetate (CA)/zeolite (Z) composite fiber was prepared by wet spinning method and studied for the removal of copper and nickel ions from aqueous solutions. Scanning electron microscopy (SEM) showed that the CA/Z fiber possessed highly porous and sponge-like structures. The influence of several variables such as initial pH value of the solution, contact time, initial metal ion concentration and temperature on the adsorption capacity of the fiber was investigated in a batch adsorption mode. The kinetic data were analyzed by the pseudo-first-order, pseudo-second-order and intra-particle diffusion models, and the experimental data were well described by the pseudo-second-order model. The equilibrium data were discussed by the Langmuir, Freundlich and Dubinin-Radushkevich isotherm models, and the adsorption isotherms were better fitted by the Langmuir equation. Thermodynamic parameters were evaluated to understand the nature of adsorption process. Desorption of metal ions was accomplished with hydrochloric acid solution, and the result showed that the adsorbent could be reused without significant loss in adsorption performance. (C) 2012 Elsevier B.V. All rights reserved.