Smectite Clay Modified with Quaternary Ammonium as Oil Remover

Clays such as smectite have high technical and economic viability due to their large adsorption capacity. These properties can be improved by treatment with acids or other modifications. This paper describes experiments to prepare and characterize organoclays and to evaluate their ability to remove oil from contaminated water in comparison with clay in its natural state. We used natural smectite clay from the municipality of Presidente Dutra, Maranhao State, modified with the quaternary ammonium salt cetyltrimethylammonium bromide. Characterization was performed by X-ray diffraction, Fourier transform infrared spectroscopy, X-ray fluorescence, thermogravimetry and determination of surface area by the Brunauer-Emmett-Teller (BET) method. The results showed appropriate conditions of the organophilization process, indicating the intercalation of quaternary ammonium cations between the clay layers. The adsorption tests showed that the natural clay reduced the amount of oil contained in the aqueous medium by 76.16%, while the corresponding removal rates of all organoclays tested were above 92%, which makes them potentially applicable to remove oil from wastewaters.