A Comparative Study on the Performance of Polyaniline-Silica and Reduced Graphene Oxide-Silica Nanocomposites to Demulsification of Oil-in-Water Emulsion

Articles in Press

Document Type : Research Article

Authors

1 1R&D Department of Arak Oil Refinery Company, Arak 3867141111, Markazi, Iran

2 2R&D Department of Arak Petrochemical Company, Arak 3867143111, Markazi, Iran

Abstract

Oily water is one of the most common issues, which is attributed to the petroleum industry in the form of oil-in-water (O-W) emulsion. Therefore, it is necessary to treat it before being released into the environment. In this study, the possibility of two different nanocomposites has been investigated in the demulsification of O-W emulsions. First, silica (SiO2) nanoparticles and graphene oxide (GO) nanosheets were synthesized using the sol-gel process and the Hummers’ method, respectively. Next, polyaniline (PANI)-silica and reduced graphene oxide (rGO)-silica nanocomposites were synthesized by applying in situ chemical oxidative polymerization and sol-gel processes, respectively. EDX analysis showed the proper reduction of GO to rGO nanosheets. In addition, SEM results revealed that the PANI-silica nanocomposite was more functional compared to rGO-silica due to its higher specific surface area and higher demulsification efficiency. Accordingly, bottle tests and optical microscopy images proved that the adsorption capacity of PANI-silica nanocomposite is greater than that of rGO-silica nanocomposite. Furthermore, BET analysis also showed that the surface area of PANI-silica was two times greater than that of rGO-silica, which caused better O-W emulsion separation. The hydrophobicity observations confirmed that the surface of PANI-SiO2 can absorb more oil droplets compared to rGO-SiO2. In addition, the impact of two effectual parameters (pH and temperature) on the demulsification performance was studied. According to the obtained results, pH showed a higher impact on the process in comparison with the emulsion temperature. The removal efficiency was estimated at 96% and 98.5% for rGO-SiO2 and PANI-SiO2, respectively. In addition, isotherm and kinetic models were also studied to gain beneficial information regarding the designing of a real adsorption system using PANI-SiO2. It figured out that the adsorption mechanism of oil on the surface of the prepared nanocomposites followed the Langmuir and pseudo-second-order kinetic models.

Keywords

Main Subjects

Iranian Journal of Chemistry and Chemical Engineering

Articles in Press, Accepted Manuscript
Available Online from 05 March 2024

Files

Share

How to cite

Statistics