Mohamad Sarmadi - School of Chemical Engineering, College of Engineering, University of Tehran, P.O. Box ۱۱۳۶۵-۴۵۶۳,Enghelab, Tehran, Iran Nuclear Science and Technology Research Institute, P.O. Box: ۱۱۳۶۵-۸۴۸۶, Tehran, Iran
Alireza Khanchi - Nuclear Science and Technology Research Institute, P.O. Box: ۱۱۳۶۵-۸۴۸۶, Tehran, Iran
Mohamad Ali Moosavian - School of Chemical Engineering, College of Engineering, University of Tehran, P.O. Box ۱۱۳۶۵-۴۵۶۳,Enghelab, Tehran, Iran
Ghasem Shahmoradi - Nuclear Science and Technology Research Institute, P.O. Box: ۱۱۳۶۵-۸۴۸۶, Tehran, Iran

The surface chemistry of inorganic materials is of great significance in a number of industrially important processes such as separation of ore by flotation, catalysis, water purification, papercoating and pharmaceutical industry. Various structure forms of magnetite (Fe3O4) nanoparticles with different surface properties have been synthesized using different methods so far. In this work, surface investigations and adsorption behavior of some lanthanide ions such as La(III), Eu(III), Lu(III), Sm(II), Y(III)in aqueous solutions have been studies using six various methods including Co-precipitation, Oxidation-precipitation,Hydrothermal, Solvothermal (EG-NaOH) & (EG-NaAC) AND Sonochemical method. The adsorption behavior (Kd) of the above mentionedmaterials onto some lanthanide ions in aqueous solutions were studied. Furthermore, X-ray powder diffraction (XRD) and Fourier transform infrared (FT-IR) techniques were employed for their characterization. The result of XRD pattern for these compounds showed that the averagedimension of all magnetites less than 100 nm. The results of adsorption experiments showed that there is a large discrepancy between Kd values. This phenomenon can be related to the difference in the hydroxyl groups concentration of six compounds. Because, the result of infrared spectra confirmed that the hydroxyl groups have different intensify in affirmation methods. It should be noted that hydroxyl groups in a surface magnetite are, indeed, the reactive parts which can react with acid or base. It can be replaced by other organic or inorganic anions, adsorb protons or metal cations, release water by heating etc.

Magnetite nanoparticles, Synthesis method, Adsorption behavior