Magnetically recoverable magnetite-reduced graphene oxide as a demulsifier for surfactant stabilized crude oil-in-water emulsion

Abstract

Oily wastewater, especially water-oil emulsion has become serious environmental issue and received global attention. Chemical demulsifiers are widely used to treat oil-water emulsion, but the toxicity, non-recyclable and non-environmental friendly characteristic of chemical demulsifiers had limited their practical application in oil-water separation. Therefore, it is imperative to develop an efficient, simple, eco-friendly and recyclable demulsifiers for breaking up the emulsions from the oily wastewater. In this study, a magnetic demulsifier, magnetite-reduced graphene oxide (M-rGO) nanocomposites were proposed as a recyclable demulsifier to break up the surfactant stabilized crude oil-in-water (O/W) emulsion. M-rGO nanocomposites were prepared via in situ chemical synthesis by using only one type Fe salt and GO solid as precursor at room temperature. The prepared composites were fully characterized by various techniques. The effect of demulsifier dosage and pH of emulsion on demulsification efficiency (E D) has been studied in detailed. The demulsification mechanism was also proposed in this study. Results showed that M-rGO nanocomposites were able to demulsify crude O/W emulsion. The E D reaches 99.48% when 0.050 wt.% of M-rGO nanocomposites were added to crude O/W emulsion (pH = 4). Besides, M-rGO nanocomposites can be recycled up to 7 cycles without showing a significant change in terms of E D. Thus, M-rGO nanocomposite is a promising demulsifier for surfactant stabilized crude O/W emulsion.

Tuning Electro-Magnetic Interference Shielding Efficiency of Customized Polyurethane Composite Foams Taking Advantage of rGO/Fe3O4 Hybrid Nanocomposites

“…Figure 3b shows the Raman spectra for the rGO and Fe 3 O 4 @rGO composites (MR5, MR10, MR20, and MR30). For the Fe 3 O 4 @rGO composites, the A 1g mode displayed at wave number 668 cm −1 confirmed the formation of magnetite in the acquired hybrid nanocomposites [35]; in the line with this, D and G bands can be easily distinguished for the rGO and Fe 3 O 4 @rGO composites. The in-plane breathing vibration of the sp 2 carbon rings is attributed to the G band recorded at a wavenumber of 1590 cm −1 for rGO [36].…”

Demulsification of Water-Containing Crude Oil Driven by Environmentally Friendly SiO2@CS Composite Materials

“…The change in pH in the waterin-crude oil emulsion may affect the flocculation/aggregation of water droplets and the demulsifying efficiency. 32 The effect of different pH values on the demulsification of the water-in-oil emulsion was investigated when the dosage of SiO 2 @CS-50 was 300 mg/L and the temperature was 70 °C. As shown in Figure 11a, when the pH value is 6, the best efficiency of 89.5% is shown.…”

Effect of Magnetic Graphene Oxide on Heavy Oil Demulsification

“…Fourier transform infrared (FTIR) spectroscopy was used to determine the functional groups on the surface of MGO and the binding mechanism of pollutants [13]. The FTIR spectra of all the studied compounds are shown in Fig.…”