화학공학소재연구정보센터
Separation Science and Technology, Vol.46, No.2, 290-299, 2011
Fe2+-modified Vermiculite for the Removal of Chromium (VI) from Aqueous Solution
A novel adsorbent: Fe2+-modified vermiculite was prepared in a two-step reaction. Adsorption experiments were carried out as a function of pH, contact time, and concentration of Cr(VI). It was found that Fe2+-modified vermiculite was particularly effective for the removal of Cr(VI) at pH 1.0. The adsorption of Cr(VI) reached equilibrium within 60min, and the pseudo-second-order kinetic model best described the adsorption kinetics. The adsorption data follow the Langmuir model more than the Freundlich model. At pH 1.0, the maximum Cr(VI) sorption capacity (Qmax) was 87.72mg center dot g-1. Desorption of Cr(VI) from Fe2+-modified vermiculite using NaOH treatment exhibited a higher desorption efficiency by more than 80%. The sorption mechanisms including electrostatic interaction and reduction were involved in the Cr (VI) removal. The results showed that Fe2+-modified vermiculite can be used as a new adsorbent for Cr(VI) removal which has a higher adsorption capacity and a faster adsorption rate.