Adsorption of copper (II) ions by using low cost activated carbon from aqueous solution

Abstract

In the present study, adsorption of copper (II) ions from aqueous solution by activated Kigelia africana rind nano carbon (KANC) was investigated under batch mode. The influence of solution pH, sorbent dose, copper (II) ions concentration, contact time, and temperature was studied. The copper (II) ions adsorption was favored with maximum adsorption at pH 6.5. Sorption equilibrium time was observed in 60 min. The equilibrium adsorption data were correlated with Langmuir and Freundlich isotherm models. The kinetics of the adsorption process was tested by pseudo-second order, Elovich and intraparticle diffusion models. It was shown that adsorption of copper (II) ions could be described by the pseudo-second order kinetic model. Thermodynamic parameters such as Gibbs free energy (ΔG⁰), the enthalpy (ΔH⁰) and the entropy change of sorption (ΔS⁰) have also been evaluated and it has been found that the adsorption process was spontaneous, feasible, and exothermic in nature. The results indicated that activated KANC can be used as an effective and low-cost adsorbent to remove Cu (II) ions from aqueous solution.