Removal of Acid Dyes from Aqueous Solutions using Chemically Activated Carbon

Abstract

Textile dyes (Acid Yellow 17 and Acid Orange 7) were removed from its aqueous solution in batch and continuous packed bed adsorption systems by using thermally activated Euphorbia macroclada carbon with respect to contact time, initial dye concentration, and temperature. The activated carbon was prepared using a cheap plant-based material called Euphorbia macroclada, which was chemically modified with K(2)CO(3). Lagergren-first-order and second-order kinetic models were used to fit the experimental data. Equilibrium isotherms were analyzed by Langmuir and Freundlich isotherms. Equilibrium data fitted well the Langmuir model in the studied temperature (25-55 degrees C) ranges. The maximum adsorption capacity of AY17 and AO7 onto activated carbon was found to be 161.29 and 455 mgg(-1), respectively by Langmuir isotherm at 55 degrees C. Breakthrough curves for column adsorption have also been studied. The desorption of dyes has been experimentally investigated using NaOH solution of pH 11.