An investigation on absorption properties of exfoliated graphite for oil spill from Caspian Sea water

Oil spills are the most important environmental impact in oceans and seas. In this article, Oil absorption, which was explored from Sardar-e-Jangal oilfield in Caspian Sea, by exfoliated graphite (EG), was investigated. Graphite was exfoliated through the reaction of graphite-CrO3 intercalation compounds with hydrogen peroxide. The obtained absorbent was characterized by Brunauer-Emmett-Teller (BET), Fourier transform infrared spectrometer (FT-IR), X-ray Diffraction (XRD), RAMAN spectroscopy, scanning electron microscopy (SEM), and Energy-dispersive X-ray spectroscopy (EDS). Absorption capacity was investigated by response surface methodology (RSM) using design expert data analysis. EG absorbed oil sample from aqueous solution to a great extent due to increasing total pore volume in its structure in comparison with simple graphite. RSM model fitting and its validation was discussed. Identified parameters (weight of absorbent and oil) were investigated by RSM using Perturbation diagram, contour and 3D surface response plots and the maximum absorption ratio was 27.6 gr oil/gr absorbent. The finding presented herein indicated that EG was successfully used in oil removal from seawater due to synthetized easily, low cost and high sorption performance.