Application of nano-magnesso ferrite (n-MgFe2O4) for the removal of Co2+ ions from synthetic wastewater: Kinetic, equilibrium and thermodynamic studies

• Published in: Applied surface science Vol. 338; pp. 42 - 54
• Main Authors: Srivastava, Varsha, Sharma, Y.C., Sillanpää, Mika
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 30.05.2015
• Subjects: Adsorption; Cobalt; Ferrite; Isotherm; Isotherms; Mathematical models; Nanoferrite; Nanostructure; Surface chemistry; Thermodynamic study; Transmission electron microscopy; Wastewater treatment; Isotherm; Nanoferrite; Adsorption; Cobalt; Thermodynamic study
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2015.02.072

•The removal efficiency of n-MgFe2O4 for Co(II) ions was investigated.•Rapid removal efficiency was observed within 60min of contact time.•The kinetic data of Co(II) followed the pseudo-second-order model.•Thermodynamic studies revealed that the adsorption reaction was spontaneous.•Desorption study demonstrated its reusability upto three adsorption–desorption cycles. The aim of this research is to investigate the adsorption characteristics of nano-magnesso ferrite (n-MgFe2O4) for the removal of Co(II) ions from aqueous solution. n-MgFe2O4 was synthesized by precipitation method. XRD of synthesized particles reveals the formation of single-phase n-MgFe2O4 nanoparticles. TEM confirms the formation of particle size in the range of 25–35nm. AFM and SEM analysis also support the TEM result. BET surface area of nanoparticles was determined to be 53.83m2/g. The adsorption of Co(II) onto n-MgFe2O4 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 67.41mg/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-MgFe2O4 can be efficiently used up to three adsorption–desorption cycles. The findings of the present study suggest that n-MgFe2O4 is very efficient for the adsorption of Co(II) ions. Adsorption efficiency of n-MgFe2O4 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.