Application of nano-magnesso ferrite (n-MgFe 2 O 4 ) for the removal of Co 2+ ions from synthetic wastewater: Kinetic, equilibrium and thermodynamic studies

Abstract

The aim of this research is to investigate the adsorption characteristics of nano-magnesso ferrite (n-MgFe 2 O 4 ) for the removal of Co(II) ions from aqueous solution. n-MgFe 2 O 4 was synthesized by precipitation method. XRD of synthesized particles reveals the formation of single-phase n-MgFe 2 O 4 nanoparticles. TEM confirms the formation of particle size in the range of 25-35 nm. AFM and SEM analysis also support the TEM result. BET surface area of nanoparticles was determined to be 53.83 m 2 /g. The adsorption of Co(II) onto n-MgFe 2 O 4 was found to be dependent on pH and the removal increased in alkaline medium. Co(II) adsorption followed pseudo-second-order model. Thermodynamic study showed that the adsorption process was endothermic and spontaneous. The equilibrium adsorption data was analyzed by two parameters and three parameters isotherm. Langmuir adsorption capacity was determined to be 67.41 mg/g. Chi-square test, standard deviations and the sum of squares of the errors (SSE) were evaluated to find out the better isotherm model. Desorption and reusability test suggested that n-MgFe 2 O 4 can be efficiently used up to three adsorption-desorption cycles. The findings of the present study suggest that n-MgFe 2 O 4 is very efficient for the adsorption of Co(II) ions. Adsorption efficiency of n-MgFe 2 O 4 for Co(II) has not yet been studied, so this study can be helpful for the treatment of Co(II) rich wastewater in near future. © 2015 Elsevier B.V. All rights reserved.