Removal of low concentration Cr(VI) from aqueous solution by modified wheat straw

Abstract

AbstractTwo kinds of adsorbents were prepared by modification of wheat straw using succinic anhydride and acrylic acid. The two adsorbents were characterized by Fourier transform infrared spectroscopy, and it was found that the carboxyl groups were introduced into the straw fiber. The use of the modified wheat straws for the removal of low concentration Cr(VI) from aqueous solutions were investigated with a variety of pH value, temperature, contact time, adsorbent dosages, and initial Cr(VI) concentration. The removal percentage achieved 99.7% at an initial Cr(VI) concentration of 1 mg/L. The adsorption kinetics experiments were carried out, and the obtained data were fitted by the pseudo‐first‐order equation, pseudo‐second‐order equation, and intra‐particle diffusion equation. The adsorption kinetics was found to conform to the pseudo‐second‐order equation with a good correlation. This study reports that the modified wheat straws are better absorbents for the removal of low concentration Cr(VI) from aqueous solutions than crude wheat straw. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013