Title : Adsorption of basic dye on grape marc based carbons activated with zinc chloride
Abstract:
Textile industries discharge large quantities of untreated colored wastewater into ecosystems which have adverse effects on the human, living and aquatic environments. The objectives of this study are: to improve and test the adsorption affinity of activated carbons from grape marc (an oenological by-product) as a biosorbents waste towards Basic dye, to verify the effect of modeling the linear form on the values of the adsorption parameters and to find the limit kinetic stage of the adsorption process. The biosorbent was applied to remove an industrial dye (basic dye) from an aqueous solution. The activation of the synthesized charcoal was carried out by two physical and chemical methods using a zinc chloride solution (chemical treatment) and induced in a muffle furnace by heating to 300 °C (physical treatment ). The materials obtained were characterized by FTIR and SEM methods The adsorption efficiency of grape marc waste with respect to the textile dye (Basic dye) tested. The evolution between the adsorption capacity and the operating conditions such as: pH of the solution, mass of adsorbent, contact time and initial dye concentration is determined by kinetic measurements. The effect of a pseudo-first order form, a pseudo-second order form, Elovich and an intraparticle diffusion form are tested for the prediction of kinetic parameters and to find the limiting kinetic step. In order to model the equilibrium data, two isotherm models are tested (Freundlich and Langmuir). The residual concentration of dye in solution was measured by spectrophotometer. All the results obtained show that the adsorption kinetics of the dye on the mate rial is well described by the pseudo second order model with a correlation coefficient R2> 0.99. The adsorption isotherms of the adsorbent/adsorbate systems studied are satisfactorily described by the mathematical model of Langmuir II and Freundlich. The pH of the solution has little influence on the bleaching performance.
