Synthesis, Characterization, and Application of EDTA-Coated Maghemite Magnetic Nanoparticles for Oil Spill Cleanup from Water Surface

Oil spills pose significant environmental, ecological, and economic challenges worldwide. Since current remediation technologies proved inefficient in restoring marine ecosystems, this study adopted a straightforward and economical method of utilizing iron oxide magnetic nanoparticles. Maghemite (γ-Fe2O3) magnetic nanoparticles (MNPs) were synthesized using a homogeneous co-precipitation method. The colloidal dispersibility of MNPs was enhanced by applying an ethylene diamine tetra-acetic acid (EDTA) coating, resulting in a reduction of high surface energy and a subsequent decrease in nanoparticle agglomeration. MNPs were characterized using X-ray diffraction (XRD), Fourier transform infrared Spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and vibrating sample magnetometer (VSM). Removal experiments occurred at 25°C with a mass range of adsorbent (0.02-0.06 g). Oil-contaminated magnetic nanoparticles were extracted from the water surface by an external magnetic field using a neodymium magnet. The effects of both the oil API and the mass of adsorbent on gravimetric oil removal (GOR) were investigated. GORs for APIs 23, 28.4, and 40.3 were found to be 10.5±0.2-2.45±0.24, 8.96±0.18-1.15±0.06, and 5.11±015 to 1.01± 0.12g/g, respectively. Experimental results demonstrated an inverse relationship between GOR and the API value, indicating that as the API value decreased, GOR  increased, and vice versa. Furthermore, as the mass of the adsorbent material was increased (0.02-0.06g), the GOR value decreased. The results of this study suggest that EDTA-maghemite MNPs have advantageous properties, including a small nanosize, super-paramagnetic behavior, and a large surface area. These characteristics make EDTA-maghemite a suitable sorbent for removing oil spills from water surfaces.