Cr(III) removal from aqueous solutions: a straightforward model approaching of the adsorption in a fixed-bed column.

Prediction of breakthrough curves for continuous sorption characterization is generally performed by means of simple and simplified equations. These expressions hardly have any physical meaning and, also do not allow extrapolation. A novel and simple approach, based on unsteady state mass balances, is presented herein for the simulation of the adsorption of Cr(III) ions from aqueous onto a low-cost adsorbent (leonardite). The proposed model overcomes the limitations of the commonly used analytical solution-based models without the need for complex mathematical methods. A set of experimental breakthrough curves obtained from lab-scale, fixed-bed columns was used to calibrate and validate the proposed model with a minimum number of parameters to be adjusted.