Chitosan-Derived Iron Oxide Systems for Magnetically Guided and Efficient Water Purification Processes from Polycyclic Aromatic Hydrocarbons

Chitosan and pyrolyzed chitosan, acting as protective layers of magnetic nanoparticles (Fe3O4 magnetite and/or metallic Fe) have been investigated to be used in magnetically-guided water remediation processes from polycyclic aromatic hydrocarbons (PAHs). Chitosan-derived magnet-sensitive materials were first obtained by a one-step co-precipitation method, then two carbon-derived magnetic chitosan materials were obtained under N2 gas flow at 550°C and 800°C, respectively. The obtained materials were investigated by means of X-ray diffraction (XRD), FTIR spectroscopy, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Magnetic Force Microscopy (MFM), and magnetization curves. Thermal treatment conditions along with the amounts of chitosan used in the synthesis processes played a critical role in the crystal structure and magnetic properties of the obtained nanomaterials. The adsorption capacity of chitosan-derived magnet-sensitive materials was tested towards PAHs, in order to evaluate their application in wastewater tertiary treatment plants. Interestingly, due to the obtained results, the use of chitosan is encouraged as a platform for the creation of green adsorbents for further developments in wastewater purification treatments.