Thermodynamic and kinetic studies for environmentaly friendly Ni(II) biosorption using waste pomace of olive oil factory

The objective of this study is to assess the environmentaly friendly Ni(II) adsorption from synthetic wastewater using waste pomace of olive oil factory (WPOOF). Batch kinetic studies were performed in order to investigate the adsorbent and adsorbate dose, solution pH, agitating speed and temperature. The maximum Ni(II) adsorption was obtained at pH 4.0. The equilibrium nature of Ni(II) adsorption at different temperature was described by the Freundlich, Langmuir and Temkin isotherms. The equilibrium data fit well the Temkin and Langmuir isotherm. The monolayer adsorption capacities of WPOOF as obtained from Langmuir isotherm at 60 °C was found to be 14.80 mg/g. The adsorption mechanism was examined by the FTIR technique. The results of the thermodynamic investigations indicated that the adsorption reactions were spontaneous (ΔG < 0), slightly endothermic (ΔH > 0) and irreversible (ΔS > 0). The pseudo first-order, pseudo second-order, Elovich and intraparticle diffusion kinetic models were used to describe the kinetic data.