Study on adsorption of some common metal ions present in industrial effluents by Moringa stenopetala seed powder

• Published in: Journal of environmental chemical engineering 2018-02, Vol.6 (1), p.1378-1389
• Main Authors: Kebede, Temesgen Girma, Mengistie, Alemayehu Abebaw, Dube, Simiso, Nkambule, Thabo T.I., Nindi, Mathew Muzi
• Format: Article
• Language: English
• Subjects: Adsorption; Industrial effluent; Metal ions; Moringa stenopetala seed
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2018.01.012

In this study, the removal of Cd2+, Pb2+ and Cu2+ ions from industrial effluent was investigated using Moringa stenopetala seed powder. The surface functionality, morphology, crystallinity, thermal stability and charge of the Moringa stenopetala seed powder was studied using FTIR, XRD, zeta potential, TGA, SEM and BET. Equilibrium isotherms, kinetic and thermodynamic models for three metal ions removal were also studied. The maximum percentage adsorption under optimum conditions of Cd2+, Pb2+ and Cu2+ ions from synthetic wastewater were 99.65, 99.66 and 99.42%, whereas that from industrial effluent were 94.17, 94.67 and 92.81%. The results of the adsorption equilibria fit the Freundlich isotherm (R2 ≥ 0.926) than Langmuir isotherm. The maximum adsorption capacity was found to be 23.26, 16.13 and 10.20 mg/g for Cd2+, Pb2+ and Cu2+ ions respectively. On the other hand, the adsorption of Cd2+, Pb2+ and Cu2+ ions were well defined by the pseudo-second order model (R2 = 1). Furthermore, the calculated values of ΔH were 54.59, 52.01 and 54.55 KJ mol−1, ΔS were 201.94 J/K−1 mol−1, 194.79 J/K−1 mol−1, and 199.45 J/K−1 mol−1 for Cd2+, Pb2+ and Cu2+ ions respectively. The positive value of ΔH indicated that the adsorption of metal ions on the adsorbent was an endothermic process.