Oil content removal from oil water emulsion by super magnetic nanoparticles

Oily wastewater treatment processes are facing challenges due to strict regulations in the quality of effluent standards and waste production. The reuse of oily wastewater treatment effluents is rapidly gaining attention for achieving sustainable water supply. Fe3O4 magnetic nanoparticles (MNPs) are widely applied as super adsorbents in industry. In the present study, the MNP was sprayed and mixed with oil-water emulsion, after the application of a magnetic field, a clear effluent was seen within minutes. The effects of the varying process parameters including, adsorbent dose, particle size, mixing time, American Petroleum Institute gravity (API gravity), pH, temperature, and oil concentration, on the percentage of oil removal and the removal capacity (mg/g) were studied. In this paper, six types of Fe3O4 magnetic nanoparticles (A:50 nm, B:15–20 nm, C:3 nm) and functionalized NH2/-COOH (A1:20–30 nm, B1:15–20 nm and C1:3 nm) were used as oil adsorbent. The highest percentage of oil removal was reached at 20 min, using 150 mg/L oil concentration, 100 mg adsorbent dose, room temperature, 28 API, and at 4 pH, and the results were 60 % (A), 72 % (B), 81 % (C), 85 % (A1), 88 % (B1) and 94 % (C1). Functionalized Fe3O4 nanoparticles exhibited higher reusability than uncoated MNPs (A-C). The results showed that Fe3O4 were highly effective, reusable, and suitable for oil removal from the oil-water emulsion. Kinetic models fit effectively with pseudo-second-order mode, and Freundlich model. This work also matches the research conducted by various researchers for oil removal from oily water using magnetic nanoparticles. [Display omitted] •Fe3O4 magnetic nanoparticles with different particle sizes and functional groups were used as an oil adsorbent.•Optimal adsorption efficiency was obtained for the functionalized Fe3O4 MNP and reached 94%.•Fe3O4 magnetic nanoparticles can be collected, cleaned, and recycled for at least 9 treatment cycles.•The adsorption kinetics follows the pseudo-second-order kinetic and Freundlich isotherm.