Study of adsorption of Cu(II) ions from aqueous solution by surface-modified Eucalyptus globulus seeds in a fixed-bed column: experimental optimization and mathematical modeling

In this study we investigated removal of Cu(II) ions from synthetic wastewater by use of surface-modified Eucalyptus globulus seeds, a low-cost adsorbent, in a fixed bed column. The surface-modified adsorbent was characterized by FTIR and SEM analysis. Column experiments were conducted to study the effect of such operating conditions as bed depth, concentration of influent Cu(II) ions, and flow rate on breakthrough curves and adsorption capacity. The applicability of different mathematical models, the Thomas, Adams-Bohart, Yoon-Nelson, and bed depth service time (BDST) models, was studied by regression analysis, and the model variables were estimated. The experimental data were examined by comparing experimental breakthrough curves with those from the model. The experimental data obtained were in good agreement with the Adams-Bohart model; for the Thomas, Yoon-Nelson and BDST models, low correlation coefficients were obtained. These results thus indicated that the Adams-Bohart model is best for simulation of breakthrough curves under different conditions.