Preparation of Fe3O4 Magnetic Material Modified by Fulvic Acid and Its Adsorption Performance for Methylene Blue

In this paper, a kind of Fe3O4 magnetic nano material modified by fulvic acid (FA) was prepared and used for removing methylene blue in wastewater. The structure and morphology of the material were characterized by FT-IR, PXRD, BET, XPS, VSM, SEM and TEM. The results showed that FA successfully coated on the surface of Fe3O4 magnetic nano particles. The newly prepared magnetic material had large specific surface area and porous structure. The specific surface area of the material was 92.15 m(2)/g. The average pore size of the material was 8.917 nm. Its saturation magnetization could reach to 55.74 emu/g. The magnetic responsiveness of the material was obvious. The magnetic material could be recovered by the magnet so it was easy to separate with the solution. The adsorption kinetic data fitted better with pseudo second order kinetic equation. The isothermal adsorption processes of the modified material to methylene blue had better linear correlation with Langmuir isothermal adsorption model. The thermodynamic parameter results indicated that the adsorption processes of the material to methylene blue were spontaneous exothermic processes. The results of the cyclic experiments indicated that the material had a certain value for reuse.