Adsorption of Chromium Ions from Aqueous Solution Using Mixed Sorbents Prepared from Olive Stone and Date Pit

Abstract

The aim of this study is to remove chromium ions from aqueous solutions by adsorption. Mixed sorbent prepared from olive stone and date pit, an agricultural solid by-product was used as adsorbent. The adsorption experiments of Cr onto the mixture of olive stone and date pit were conducted at different parameters such as, per cent of olive stone and date pit in the mixture, temperature, initial solution pH and initial chromium concentration. Adsorption isotherms were obtained at different per cent of olive stone and date pit in the mixture. This adsorption data was fitted with the Langmuir, Freundlich and Temkin isotherms. In addition, the thermodynamic parameters, standard free energy (DGº), standartd enthalpy (DHº) and standard entropy (DSº) of the adsorption process were calculated. The results show that the mixture sorbent from olive stone and date pit is an alternative low-cost adsorbent for removing chromium ions.