Removal of Cr(VI) and Cu(II) ions from aqueous solution by rice husk ash—column studies

In this present study, the technical feasibility of rice husk ash for adsorptive removal of Cr(VI) and Cu(II) is examined in packed bed from aqueous solutions. The effects of different operating parameters such as height of the packed bed column (5–15 cm), flow rate of aqueous metal ion solution (10–30 ml min−1), and initial metal ion concentration (10–30 mg L−1) were studied. Capacity of the bed to absorb metal ions was found to increase with an increase in bed height, decrease in flow rate, and metal ion concentration. Adams–Bohart, Yoon–Nelson, and Thomas models were applied to the experimental data for the prediction of breakthrough point and also to determine the model parameters to characterize the column. The Yoon–Nelson model and Thomas model were applicable for Cr(VI) removal, and for Cu(II), Thomas model was suited.