Synthesis and Characterization of Goethite Nanostructured powder: Application in the Simultaneous Removal of Co(II) and Ni(II) Ions from Aqueous Solution

This study investigates the adsorption efficiency of goethite nanostructured powder for the simultaneous removal of cobalt and nickel ions. The nanostructured powder sample was synthesized via a chemical precipitation technique and characterized using SEM, FTIR-ATR and XRD techniques. From batch adsorption studies, maximum absorption for Co(II) and Ni(II) ions occurred at an equilibrium contact time of 80 min, with an adsorbent mass of 0.1 g, and at pH=7. Co(II) ions showed greater affinity to the nanoparticles as compared to Ni(II). The maximum quantities adsorbed were recorded as 148.5 mg/g for Co(II) and 110.6 mg/g for Ni(II) ions. The best isotherm model fit for both metal ions was the Freundlich model indicating heterogeneity of the surface binding sites. The pseudo-second order kinetic model was the best-fit model: an indication of a strong chemical adsorption between the adsorbent surface and metal ions. The findings show that the goethite nanostructured powder is a very effective adsorbent material and prominent candidate for the simultaneous removal of cobalt and nickel ions from water.