Magnetic removal of nitrate ions from aqueous solution using amino-silica coated magnetic nanoparticles modified by oxovanadium(IV) porphyrin

In this study, we have treated nitrate contaminated groundwater using modified magnetic nanoparticles. The modification of magnetite nanoparticles were conducted by 3-aminopropyl- triethoxysilane followed by oxovanadium(IV) porphyrin in order to enhance the removal of nitrate ions. Fourier Transform Infrared Spectroscopy (FT-IR),diffraction (XRD), Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM) were used to characterize the synthesized nanoparticles. The effect of pH, contact time, sorbent dosage and some co-existing anions present in aqueous solutions were investigated. The isothermal data of nitrate sorption conformed well to the Langmuir model and the maximum sorption capacity of nanosorbent for nitrate was 76.92 mg.g -1 . Thermodynamic study indicated that the adsorption is endothermic and spontaneous. Regeneration of nitrate adsorbed material could be be by NaOH and the modified magnetic nanoparticles exhibited good reusability.. proposed system can provide a fast and efficient removal of the nitrate ion by using just an external magnetic field. The competitive adsorption tests verified that, this system has good adsorption selectivity for nitrate ions.