Removal of silica from aqueous solution using magnetic nano-composite

Iron oxide/sepiolite magnetite composite (MSep) was prepared by a chemical precipitation method. The composite was characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and specific surface area (BET) analysis. Batch mode adsorption studies were performed to evaluate the adsorption kinetics, adsorption isotherms, and selective recognition of MSep. The equilibrium data was evaluated using Langmuir and Freundlich isotherm. The kinetic data were analyzed using pseudo-first-order and pseudo-second order equations. The pseudo-second-order exhibited the best fit for the kinetic studies. Equilibrium data fitted by Langmuir adsorption isotherm. The adsorption was analyzed thermodynamically. It was concluded that MSep nanocomposite is an effective material for the removal of silica from aqueous solutions