Evaluation of analytical and numerical solutions of mass transfer model for breakthrough curves simulation: Co2+ adsorption by hydrogen peroxide-bio-originated composite.

Accurate estimation of breakthrough curve (BTC) is required to scale -up the column adsorption process. A mathematical model (unsteady advection-dispersion-diffusion-adsorption equation) was solved analytically and numerically to simulate the dynamic adsorption of Co(II) ions on hydrogen peroxide-modified bone waste. The performance of both analytical and numerical approaches was evaluated under varying initial Co(II) concentrations (25, 50 and 75 mg L-1), bed heights (3, 6 and 9 cm), flow rates (0.6, 1.2 and 1.8 mL min-1), and pH (2, 4, 6, 8). Both analytical (R2 = 0.990) and numerical (R2 = 0.993) approaches described the experimental data well. The comparison results indicate that in spite of the capability of the analytical modeling for predicting the BTC (NRMSE = 9.32%), numerical modeling is more efficient in the simulation of Co(II) adsorption by adsorbent (NRMSE = 7.56%). So, it can be concluded that analytical modeling can be an easy and quick alternative to numerical modeling for predicting BTC with acceptable accuracy.