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

ABSTRACT

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°C–800°C) in an inert atmosphere was done and the grains at 700°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.

KEYWORDS:

• Aerogel
• Caspian sea
• graphene/chitosan
• oil absorption
• response surface methodology

Acknowledgments

This work is supported by Khazar oil exploration and production company (KEPCO) under its research programs. The authors wish to thank school of environment, college of engineering, University of Tehran for support. Also, we want to thank Khazar Exploration and Production Company (KEPCO) for supplying an oil sample which was explored from Caspian Sea.