Preparation of Xanthan Magnetic Biocompatible Nano-Composite for Removal of Ni^2+ from Aqueous Solution

This study investigates the uptake of the nickel (II) metal ions from aqueous sources using the xanthan magnetic biocompatible nano-composites. The desired nano-sorbent was first synthesized, analysed, and evaluated by scanning electron microscope (SEM) and Fourier transform infrared spectroscopy and (FT-IR), then used as adsorbent for removing the nickel from aqueous solution. Then the effect of different parameters such as contact time, adsorbent amount, pH, initial concentration, and temperature on the adsorption rate was investigated. The equilibrium time for the stirring state was 60 min and the optimum adsorbent value was 0.1 g and the acidity of 4 was the best pH. The highest removal efficiency was obtained at 97.6%. The kinetic studies of nickel removal by the synthesized adsorbent were performed and the results obtained for batch experiments follow the pseudo-quadratic kinetic model with (R2=0.9987). Equilibrium adsorption studies also revealed that, the adsorption process was in better agreement with the Freundlich isotherm (R2=0.9978). The positive Gibbs free energy (15.08 KJ/mole-1) showed that the process was spontaneous. Also the entropy changes was positive (0.03 KJ/mole-1), indicated an increase in entropy during the adsorption process in the system. Therefore, the adsorption process was associated with increasing the disorder.

کلیدواژه ها:

Adsorption ، Hydrogel adsorbent ، nickel ، Nickel-xanthan removal