Adsorption of Cr(VI) on crosslinked chitosan–Fe(III) complex in fixed-bed systems

Fixed-bed column studies were conducted to evaluate the performance of crosslinked chitosan–Fe(III) complex (Ch–Fe) for the adsorption of Cr(VI) in aqueous medium under dynamic conditions. Solution pH, column bed height, inlet Cr(VI) concentration and influent flow rate were variable parameters for the present study. The results revealed that the prepared adsorbent had significant adsorption capacity (148.4 mg/g) for Cr(VI). The breakthrough data obtained for Cr(VI) was more adequately described by the Thomas and Clark models indicated that Cr(VI) adsorption mechanism by Ch–Fe was a Langmuir-type sorption and followed pseudo- second order kinetics monolayer chemical sorption. Good agreement was observed between the predicted theoretical breakthrough curves and the experimental results. The high Cr(VI) adsorption capacity and regeneration efficiency of Ch–Fe suggests its applicability in the removal of chromate ions present in industrial wastewater.