Adsorption of azo dyes onto a corncob in packed column at the constant velocity of front propagation

Abstract

Practical use of adsorption involves conducting the process in a packed bed column. The sorbent bed allows removing the contaminants from water or another solvent. Adsorption is most often applied to the treatment of aqueous solutions such as removal of hardness, heavy metal ions, colorants, pesticides, humus, and other organic and inorganic pollutants appearing in the water environment. Adsorption from low-concentration solutions is the main area of application of this process. Description of column adsorption presented in this paper uses a moving observer whose velocity is equal to the velocity of concentration front movement. This approach reduces the system of partial differential equations to ordinary differential equations. The method is able to predict the breakthrough time, saturation time as well as calculate the changes in concentrations with time and at different locations inside the column. Direct orange azo dye and properly prepared corncobs were used in the experiments. The column was operated at various initial dye concentrations, volumetric flow rates, and bed heights.