Adsorptive Removal of Trivalent Chromium in Aqueous Solution Using Precipitate Produced from Aluminum Tanning Wastewater

摘要

Precipitate adsorbent was produced from aluminum tanning wastewater by alkali precipitation and characterized by XPF, XRD, and FTIR. The results showed that the main components of the precipitate were Al, Ti, and Zr. The adsorption equilibrium for Cr~(3+) on the precipitate was reached within 60 min. The precipitate had better removal for Cr~(3+) from waste-water at pH 7.0. The kinetic process of adsorption can be described by the pseudo-second-order kinetic equation, and the adsorption isotherm fitted to the Langmuir model very well. Co-existed cations (Na~+, Ca~(2+)) in aqueous solution restrained Cr~(3+) adsorption on the precipitate. The adsorption of Cr~(3+) on the precipitate was mainly through the complexation and ion-exchange mechanisms, and oxide may play a major role in Cr~(3+) adsorption process.