Removing Co(<scp>II</scp>) and Mn(<scp>II</scp>) ions effectively from aqueous solutions by means of chemically non‐processed Mardin stone waste: Equivalent, kinetic, and thermodynamic investigations

Abstract

Abstract Mardin stone waste (MSW) was used to explore the removal of cobalt (II) and manganese (II) ions from aqueous solutions. Kinetic data collected at various temperatures were applied to different kinetic equations. Different adsorption isotherm models were evaluated to better understand the adsorption process. Energy dispersion spectroscopy (SEM), X‐ray diffraction (XRD), and Fourier transform infrared spectroscopy (FT‐IR) were used to analyze the surface characteristics of MSW. Results indicated that the Langmuir isotherm model, which accounts for chemical absorption and potential irreversibility of the process, may be used with the isotherm data. The adsorption of Co 2+ and Mn 2+ ions yielded kinetic data that was best characterized as pseudo‐second‐order with the greatest regression coefficient. While the adsorption capacity of the Co 2+ ion was determined to be 7.34, 7.75, and 8.19 mg g −1 at 298, 308, and 318 K, respectively, the adsorption capacity of Mn 2+ was calculated to be 8.20, 8.42, and 8.78 mg g −1 under the same circumstances. The adsorption of Co 2+ and Mn 2+ ions by means of MSW was natural and exothermic according to thermodynamic analyses.