VALORISATION DES FEUILLES D'OLIVES POUR L'ELIMINATION DU Zn

Abstract

The objective of this study is to investigate the possibility of applying olive leaves as a adsorbant for the removal of heavy metal. The effects of operating parameters such as initial solute concentration, sorbent mass, medium temperature, solution pH and ionic strength were examined. The preliminary study gives satisfactory results with a contact time of 75 minutes and at pH=7 a yield equal to 87.5% and at temperature 13°C. The equilibrium is perfectly described by the Temkin model. Thermodynamic parameters such as Gibbs free energy (ΔG0), enthalpy (ΔH0) and entropy (ΔS0) were also evaluated and they showed that the adsorption process was spontaneously feasible and the enthalpy variation is negative, which indicates the exothermicity of the sorption process. The value of entropy variation is negative demonstrating a slight increase in disorder at the solid-solution interface during zinc sorption. The results of the present study show that olive leaves can be advantageously used as a low cost adsorbant for the removal of zinc from water and industrial effluents.