Oil Recovery from Water under Environmentally Relevant Conditions Using Magnetic Nanoparticles

Large oil spills and oily wastewater discharges from ships and industrial activities can have serious impacts on the environment with potentially major economic impacts. Current oil remediation techniques are inefficient and may have deleterious environmental consequences. However, nanotechnology offers a new route to potentially remediate oil pollution. In this study, a cheap and facile hydrothermal method was developed to synthesize polyvinylpyrrolidone-coated magnetite nanoparticles to separate a reference MC252 oil from oil-water mixture under environmentally relevant conditions. Fluorescence and Proton nuclear magnetic resonance spectroscopy results showed near 100% oil removal from oil-water mixture in the ultrapure water under optimum condition. Based on gas chromatography-mass spectrometry data, approximately 100% of lower molecular mass alkanes (C9-C21) were removed within 10 min of magnetic separation and by increasing the separation time to 40 min, greater than 67% of C22-25 alkanes were removed. Moreover, nanoparticles removed near 100% oil from synthetic seawater solutions in the presence and absence of fulvic acid showing excellent oil removal capacity of the nanoparticles under different conditions. Results show that these nanoparticles can be utilized to remove oil over a short time with a high removal efficiency under environmentally relevant conditions.