Adsorption of nickel(II) ions from aqueous solutions using Malatya clay: Equilibrium, kinetic, and thermodynamic studies

Abstract

This paper evaluates Malatya clay (MC) for the removal of Ni(II) ions from aqueous solutions. For adsorption efficiency, the impacts of several factors, such as pH, starting metal ion concentration, and contact duration, were examined. The optimal initial Ni(II) ion concentration was determined to be 5 mg/L, the adsorption contact duration was 360 min, and the solution's pH was 6.27. Using scanning electron microscopy, energy dispersive spectroscopy, and Fourier transform infrared spectroscopy, the surface characteristics of Malatya clay were examined. The isotherm data fit the Langmuir isotherm model, indicating chemical adsorption and likely irreversibility of the process, according to the results. At 298, 308, and 318 K, the adsorption capacities of Ni(II) were determined to be 10.267, 11.834, and 12.285 mg/g, respectively. Adsorption kinetic data revealed that the adsorption of Ni(II) metal ions followed the pseudo-second-order kinetic model. According to thermodynamic studies, Ni(II) ion adsorption on the MC is spontaneous and endothermic. MC has proven to be an effective and alternative material for the removal of Ni(II) ions from aqueous media due to its excellent removal ability, availability, and low cost, as well as its features such as being able to be used without any chemical treatment and being environmentally friendly.