Removal and Recovery of Dissolved Oil from High-Salinity Wastewater Using Graphene–Iron Oxide Nanocomposites

oleh: Ahmad Diraki, Hamish R. Mackey, Gordon McKay, Ahmed Abdala

Format: Article
Diterbitkan: MDPI AG 2022-09-01

Deskripsi

We report the synthesis of reduced graphene oxide (rGO)-α-Fe<sub>2</sub>O<sub>3</sub> nanocomposite and its application to remove and recover dissolved oil from a high-salinity oil–water emulsion in batch and column/breakthrough setups. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and nitrogen adsorption characterized the synthesized nanocomposite’s structure, morphology, and surface properties. Both batch and continuous breakthrough adsorption studies were investigated. The effect of the adsorption parameters on the adsorption capacity and removal efficiency was analyzed. The rGO-Fe<sub>2</sub>O<sub>3</sub> nanocomposite (rGO-Fe<sub>2</sub>O<sub>3</sub>-NC) demonstrated a superior adsorption capacity, both when measured experimentally (1213 mg/g) and predicted using the Freundlich isotherm (1301 mg/g). The adsorption process followed pseudo-second-order kinetic, and the rGO-Fe<sub>2</sub>O<sub>3</sub>-NC exhibited a very rapid removal, with more than 60% of oil being removed within 10 min. Breakthrough confirmed the exceptional removal capacities with good regeneration and cycling ability under a short contact time. Moreover, the adsorption capacity was enhanced with an emulsion salinity of up to 100,000 ppm, confirming the suitability for high-salinity wastewater.