New process for the treatment of polluted water using the coupling of nanoparticles (Fe3O4) and intense magnetic system

Abstract

The aim of this study is to reduce the indicators of the amount of oxidizable pollutants present in polluted water, using magnetite Fe3O4 nanoparticles (MNPs) as adsorbents in combination with a high intensity magnet. The MNPs used as adsorbents were synthesised by coprecipitation method and analyzed by Transmission-Electron-Microscopy (TEM), scanning electron microscopy (SEM), X-ray Diffraction Analysis (XRD), Fourier transform infrared spectroscopy (FTIR), surface area analysis (BET) and Thermo-Gravimetric-Analysis (TGA). The performance on the reduction efficiency of the contaminated water was investigated under different conditions: pH (4-9), adsorbent masses (0.5 g/L -1.5 g/L), contact times (15-90min), and stirring rates (50-300 rpm). The nanoparticles produced by co-precipitation showed a smaller size than the other techniques (10 nm). The optimum results of the treatment with Magnetite indicate the reduction conditions: contact time of 50 minutes, pH of 8, mass of magnetite of 1 g/l and stirring speed of 200 rpm. A use with a coupling of nanoparticles and an intense magnetic field (1T) generates better treatments up to 85% COD and 86% BOD5.