Evaluating the Effect of Thermal Activation on Separation Process of Insoluble Fraction of Gasoline using Red Mud

Contamination of water resources with petroleum products is a serious environmental problem. The current study was carried out to investigate the effect of using raw and heat activated red mud (RM) as adsorbent to remove insoluble fraction of gasoline from aqueous solution. Some parameters such as pH, contact time, adsorbent dose and initial concentration were optimized in adsorption process to obtain the highest removal efficiency. Maximum removal of gasoline by raw and heat activated red mud at pH 8 and 7 were 90% and 92% respectively, during the contact time of 30 minutes, adsorbent dose of 50 g/L and 1% initial concentration of gasoline were the same for both adsorbents. Study of isotherm for raw and heat activated red mud showed high consistency with Langmuir and Freundlich isotherms, respectively. The kinetics of adsorption process was described by a pseudo-second-order model for both adsorbents. Experimental adsorption capacity of raw and heat activated red mud was achieved 0.7 and 0.66, respectively. According to the results, the adsorbents used in this study, have an appropriate efficiency for removal of the insoluble fraction of gasoline from aqueous solution.