Removal of Oil Spills from Salty Waters by Commercial Organoclays

In this study two commercial organoclays, Cloisite 15A and Cloisite 30B, were used to investigate their potential for removing of light and heavy crude oils from salty waters. The results of batch kinetic studies indicated that the equilibrium time can be reached within 25–30 minutes of contact time. In addition experiments were performed to determine the effect of salinity, temperature, pH and mixing time on the adsorption process. The adsorption isotherms were obtained for the crude oils at equilibrium, at an optimum pH value of 11.73 and temperature of 19°C for which the initial oil contents varied in the range of 100 to 2000 ppm. Experimental results showed that oil sorption onto these organoclays can be described by Freundlich isotherm. Further, it was found that the oil removal efficiency for Cloisite 30B is higher than that of Cloisite 15A and the greater sorption was observed for Gachsaran crude oil onto the organoclays over Soroosh crude oil.