Biosorption of Cr(VI) from aqueous solutions by Eichhornia crassipes

This paper reports the research findings of a laboratory-based study on the removal of Cr(VI) from solution using the biomass (both roots and stems) of the non-living Eichhornia Crassipes as a biosorbent. The effect of physico-chemical parameters like pH, sorbent dose, contact time and initial concentrations were investigated. Although the Lagergren first order model was applicable to some of the data, the pseudo-second-order reaction model was applicable to all data. The Freundlich isotherm was found to represent the measured sorption data well. The Fourier transform infrared spectrometry showed that the hydroxyl group was the chromium-binding site within pH range (pH 1-5) where chromium does not precipitate. The results indicated that the biomass of E. Crassipes is suitable for development of efficient biosorbent for the removal of chromium from wastewater of chemical and allied process industries. (c) 2005 Elsevier B.V. All rights reserved.