Magnetic hollow buoyant alginate beads achieving rapid remediation of oil contamination on water

Oil spills are a worldwide concern because of their negative impact on the environment. Thus, the development of simple yet effective methods for oil pollution remediation remains a significant global challenge. Of remediation techniques for oil removal, those involving adsorption are superior, but most reported adsorbents sink in water and are, consequently, difficult to collect after adsorption, generating secondary pollution. Thus, we developed magnetic maleic anhydride-alginate graphene oxide hollow beads (GO-MAGB-MA). Here, we report the characterization of GO-MAGB-MA, involving scanning electron microscopy, energy dispersive X-ray spectrometry, Raman spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, and vibrating sample magnetometry. The experimental data fit the pseudo-second order kinetic model, having a chi-squared (χ2) ≤ 0.0069, average relative error (ARE) ≤ 0.4094, and coefficient of determination (R2) ≥ 0.9998, and the Freundlich isotherm, having χ2 ≤ 3.33 × 10-4, ARE ≤ 0.2349, and R2 ≥ 0.9966, indicating that removal of oil was the rate-limiting step on heterogenous multilayer system. In comparison with other previous reported adsorbents, the GO-MAGB-MA shows superiority in term of adsorption process which was pH independent, rapid equilibrium adsorption and high adsorption capacity. GO-MAGB-MA also remained buoyant and magneto-responsive during adsorption process made it easy to be-recollected and regenerated while other reported adsorbents tend to sink during adsorption, and difficult to be re-recollected and ended as secondary pollutants. For future application, Combination with other technologies such as skimmer and continuous column adsorption experiment can be conducted for larger-scale oily water remediation.