Crude oil-water separation with the aid of carbon based materials

Abstract Carbon-based materials are commonly utilized in water filtration and purification due to their affordability and environmental friendliness. This study investigates the effectiveness of four different carbon-based materials: activated carbon (AC), graphene oxide (GO), reduced graphene oxide (rGO), and polyethylene (PE) in crude oil–water separation. To test the effectiveness of the separation, light transmission measurements were carried out with the aid of Arduino UNO using a red, green, and blue (RGB) light spectral sensor. The results revealed that the emulsions with AC was the most effective material in the separation, followed by rGO, and GO was the least effective. To explain the mechanism behind the separation performance, the carbon materials have been characterized by x-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FTIR). The effectiveness of AC and rGO in the separation process was directly related to the quantity of surface oxides. The experimental results are perfectly agreed with published Density functional theory (DFT) calculations of HOMO–LUMO gap energies. AC shows the best performance and the smallest gap, which indicates that it requires less energy for electrons transition between the HOMO and LUMO. This phenomenon can be attributed to the affinity towards hydrogen in the hydrocarbon chains in crude oil.