Adsorption kinetics and thermodynamics of Azure C dye from aqueous solution onto activated charcoal

Adsorption thermodynamics and kinetics of Azure C and from the aqueous solution on activated charcoal was examined. The charcoal was activated by concentrated sulphuric acid and the adsorption kinetic and thermodynamic was tested in batch experiment. An experiments used the adsorption batch method to observe the effect of the variable parameters, i.e. concentration of dye, time of contact, pH, temperature and adsorbent dose. The ideal dosage of adsorbent was 0.3 g for Azure C. The equilibrium state was reached within 60 min for dye Azure C at activated charcoal. The isotherms of equilibrium were investigated to characterize the adsorption operation. The data for the kinetics study were adjusted utilizing the equation of pseudo- second-order and the model of diffusion (intra-particle). All data were evaluated by means of equilibrium Freundlich, Langmuir and Temkin isotherm on activated charcoal surface. Based on the adsorption isotherm evaluation on activated charcoal the result was 4S by using Giles classification. The thermodynamic factors like ΔH, ΔG and ΔS were estimated.