Removal of Nickel (II) from Aqueous Solution Via Carbonized date Pits and Carbonized Rice Husks

The adsorption of nickel from liquid solutions onto carbonized date pits (CDP) and rice husks (CRH) has been investigated in the current study. The process was studied in a batch system with respect to the initial pH, contact time, temperature, adsorbent dose and nickel initial concentration. The results showed that the experimental data was well represented by first order model for CDP and second order model for CRH. Based on the kinetic modeling, the apparent activation energies calculated were 7.84 kJ and 18.502 kJ/mol for CDP and CRH, respectively. The results also indicated that process of nickel uptake by CDP and CRH was physical adsorption process. The equilibrium data for CDP indicated that it fitted both Freundlich and Langmuir models. However, adsorption onto CRH fitted Freundlich model better based upon the higher value of R2 obtained. The thermodynamic parameters (ΔHº, ΔSº and ΔGº) calculated from the experimental data indicated that the process was endothermic and spontaneous