Adsorption and Desorption Performance of Acacia nilotica for the Removal of Cobalt(II) by Column and Batch Mode Study from Aqueous Phase and its Suitability in Real Waste Water

This study on the removal of cobalt ions from aqueous solutions by Acacia nilotica was conducted in batch and column method. The operating variables studied were contact time, initial solution pH, initial metal concentration, temperature and adsorbent dosage. Kinetics and isotherm models were validated to understand the mechanism of adsorption of Co(II) ion by Acacia nilotica. Thermodynamic properties such as ΔG˚, ΔH˚ and ΔS˚ were determined for the cobalt adsorption. Further, the adsorption of cobalt ion was confirmed through instrumental analyses such as SEM. In column studies, the decrease of the flow rate resulted in the increase of the removal efficiency. The desorption and recyling ability of adsorbent was found to be good. We conclude that such modified Acacia nilotica can be used for the efficient removal of Co (II) ions from aqueous and industrial wastewater.