Adsorption Kinetics and Adsorption Isotherm of Methylene Blue on Magnetic 0.9NiFe₂O₄/0.1SiO₂ Nanocomposites Prepared via a Rapid Combustion Process.

Abstract

Magnetic 0.9NiFe2O4/0.1SiO2 nanocomposites were successfully prepared via a rapid combustion process, and the morphology and magnetic properties of them were investigated by TEM, XRD, VSM, and BET techniques. The magnetic 0.9NiFe2O4/0.1SiO2 nanocomposites calcined at 400 °C for 2 h with absolute alcohol of 20 mL were characterized with the average particle size of about 28 nm and the specific magnetization of 192.0 Am2/kg. The magnetic 0.9NiFe2O4/0.1SiO2 nanocomposites were employed to remove methylene blue (MB) from aqueous solutions, the adsorption kinetics and adsorption isotherm of MB onto 0.9NiFe2O4/0.1SiO2 nanocomposites at room temperature were investigated, and the regression equations were found in good agreement with the pseudo-second-order model in the initial MB concentrations of 100-600 mg/L; the adsorption equilibrium data of MB onto 0.9NiFe2O4/0.1SiO2 nanocomposites at room temperature were analyzed with Langmuir, Freundlich and Redlich-Peterson models, and the adsorption isotherm was most effectively described by the Redlich-Peterson model based on the value of the correlation coefficient (0.9810).