Adsorption of heavy metal ions on olive leaves: Equilibrium and kinetic studies

In this study the adsorption of Cu2+، Pb2+ and Cr3+ ions from aqueous solution using olive leaves ash were investigated. The equilibrium adsorption level was determined as a function of the solution pH، temperature، contact time and adsorbent doses. Adsorption isotherms of heavy metal ions on adsorbents were determined and correlated with common isotherm equations such as Langmuir، Freundlich and Tempkin models. These studies were showed that the Langmuir isotherm model was fitted well with adsorption data. Kinetic studies were carried out on various kinetic models such as pseudo-first order، pseudo-second order and intra particle diffusion model. The pseudo-second order kinetic model was fitted very well with experimental data. Base on thermodynamic studies، this process was both endothermic and spontaneous، enthalpy and entropy were negative.