Bioremoval of hexavalent chromium from aqueous solutions by the brown seaweed Dictyopteris polypodioides

Abstract

In this study, the uptake of hexavalent chromium using biomass of the brown seaweed Dictyopteris polypodioides was studied to evaluate its biosorption capacity. Optimum conditions for Cr (VI) elimination were determined by studying the effect of initial solution pH, biomass dosage, contact time and initial Cr (VI) concentration. The elimination of hexavalent chromium was strictly pH dependent and maximum sorption was obtained at more acidic pH. The removal rate of Cr (VI) was relatively quick during the first 10 min of contact before reaching equilibrium in about 15 min. The isotherm data were found to be well fitted by linear Langmuir equation. Pseudo-second order model was found appropriate to explain the adsorption kinetics more effectively. The results of the present study suggest that Dictyopteris polypodioides biomass could be used as an effective and low-cost biosorbent for Cr (VI) removal from aqueous solution.