Chromium(VI) removal from aqueous medium by maize cane and agave bagasse biomasses

Abstract

Chromium(VI) is a major water pollutant from industrial effluents whose concentration is to be reduced within the permissible limits. In this paper, the use of maize cane and agave bagasse as inexpensive adsorbent for the removal of Cr(VI) from aqueous solutions is considered. In the first place, they were conditioned and characterized to determine their physicochemical properties with scanning electron microscopy; the elemental composition with energy-dispersive x-ray spectroscopy (EDS); the principal functional groups with Fourier transform infrared spectroscopy; thermal stability with thermogravimetric analysis; and surface properties by specific surface hydration kinetics, point of zero charge determination by mass titration, and active site density are described. In the second place, their adsorption properties for Cr(VI) from aqueous solution were evaluated in a batch system. The kinetics of Cr(VI) sorption with both natural adsorbents were described with a pseudo-second-order model. Equilibrium data were found to be best represented for both adsorbents by the Freundlich isotherm model. Maize cane and agave bagasse can be effectively used as an adsorbents for the removal of Cr(VI) ions from the aqueous solution.