Removal of dark colored compounds from date syrup using activated carbon: A kinetic study

Dark colored compounds in date syrup have been removed using powdered activated carbon (PAC) at different operating conditions including different temperatures (30, 40, 50 and 60 degrees C), as well as different PAC concentrations (0.04, 0.06, 0.08, 0.1 and 0.12 g ml(-1)). Adsorption isotherms of Langmuir, Freundlich, Tempkin and Harkins-Jura were selected to fit the equilibrium data at different operating temperatures. The isotherms were correlated based on the absorbance intensity and the concentration of a colored compound, which gives the same absorbance intensity as the real date syrup. Among the adsorption models, the Langmuir isotherm best fitted the experimental data with coefficient of 0.99. To study the adsorption kinetics, the pseudo-first order and the pseudo-second order models were evaluated to fit the experimental data. The pseudo-second order equation fitted the experimental data very well. (c) 2012 Elsevier Ltd. All rights reserved.