Spilled oil absorption from Caspian sea water by graphene/chitosan nano composite

In the present work, spilled oil sorption, which was explored from Sardar-e-Jangal oilfield in Caspian Sea, by Graphene/Chitosan Nano composite (GC Aerogel or GC), was investigated. Graphene oxide was prepared according to the modified Hummers method and Oxidation & thermal reduction methods were used for the GC preparation. GC grains Pyrolysis at elevated temperatures (25 degrees C-800 degrees C) in an inert atmosphere was done and the grains at 700 degrees C was found as the best absorbent with high strength, stability, super hydrophobicity, and sorption capacity. The GC absorbent was characterized by scanning electron microscopy (SEM), and Energy-dispersive X-ray spectroscopy (EDS), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectrometer (FT-IR), X-ray Diffraction (XRD), and RAMAN spectroscopy. Absorbance efficiency was investigated by response surface methodology (RSM) using design expert data analysis. GO 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 48.2 gr oil/gr absorbent. The most exciting advantages of this method are its low-cost, massive scalability, and high sorption performance, indicating that the aerogels are promising materials for the treatment of oil-spill accident oily wastewater.