Removal of methylene blue from water solution by modified nanogoethite by Cu

In this study, nanocopper goethite (Cu-goethite) was synthesized and used to adsorb of methylene blue (MB) solution. The prepared nanoparticles were characterized by scanning electronic microscopy (SEM), energy dispersed X-ray spectroscopy (EDS), mapping image, X-ray diffraction (XRD), Fourier- transform infrared spectroscopy (FTIR) and the N2 absorption (BET specific surface area) and pore size distribution analysis. The effects of experimental parameters, that is, pH, contact time, temperature, and initial concentration, were studied on adsorption. The results indicated that the optimum conditions for 40 mg L–1 MB solution were pH = 9 and 5 g L–1 Cu-goethite as well as pH of 10 and 7 g L–1 goethite along with the contact time of 30 min. Besides, the equilibrium sorption data were fitted into Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich isotherms. The results also revealed that the equilibrium data were perfectly represented by the Langmuir isotherm for the adsorbents. The pseudo-first-order and pseudo-second-order models were employed to analyze the kinetics data and the adsorption behavior was better described by the pseudo-second-order model. Moreover, thermodynamic parameters have been evaluated and it has been found that the sorption process was spontaneous and exothermic in nature. Cu-goethite as an alternative adsorbent can be used for dye removal in wastewater treatment processes in the future environment governance.