In recent years, separation of organic/organic mixtures especially azeotropic , isomer or close boiling mixtures has attracted significant attention in the research community. A group of organic/organic mixtures is polar/non polar mixtures. These mixtures have conventionally been separated by different method such as adsorption. In the present work the feasibility of using a non polar adsorbent known as exfoliated graphite (EG) for separation of polar/non polar mixture of MTBE/MEOH has been studied. To complete a previous work in which separation of MTBE from water had been studied, effect of ultrasound irradiation on this case was also studied. In the case of removal of methanol from MTBE, four main effecting parameters were recognized to study their effects on the adsorption capability of EG. The two parameters of temperature of high temperature thermal treatment and nitric acid/sulfuric acid ratio were related to the synthesis process of adsorbent whereas MTBE/MEOH ratio in the solution and adsorbent to solution ratio were other factors related to adsorption stage. In the experiments of adsorption of MTBE from aqueous solution by the means of EG in the presence of ultrasonic irradiation , effect of three factors of pH, specific volume of EG and amount of EG in solution were studied. To decrease the number of required experiments and determining the contribution of each factor, the Taguchi method was used for design of the experiments of the MTBE removal from MEOH. By using this method and application of orthogonal array of L 16 , optimum condition for eliminating MTBE from MEOH was predicted. According to the obtained results, EG was able to eliminate MTBE from MEOH at optimum condition effectively and at this condition the percentage of MTBE in solution decreased to about 20% of its initial value. Also in other set of experiments it was found that applying ultrasonic irradiation had a considerable positive effect on the removal of MTBE from its aqueous solution. Although applying ultrasonic irradiation had no effect on the separation of MTBE from methanol.
