There are several technologies for the treatment of oily wastewater generated by the oil industry, not only to separate the emulsified oil in water, but also to reduce its concentration in the aqueous effluent. Among the processes of separation, the separation using membranes should be highlighted when they become an effective material and it also resistant to high temperatures, have good corrosion resistance, easy to clean, and have long life operation, among others. This work aims to synthesize the material (ZSM-5, γ-alumina membrane, and zeolite membrane ZSM-5/γ-alumina) and to evaluate the membranes in the oil/water separation in a continuous flow system. From the XRD results of the individual materials, it can be observed the formation of all the characteristic peaks for each material. The EDX analysis of zeolite ZSM-5 showed the formation of this material with a Si/Al = 19. From the SEM image of these materials, it can be seen that the surface of the γ-alumina is completely covered with ZSM-5 zeolite crystals. The oil/water removing, using ZSM-5 γ-alumina membrane, showed high retention of the oil, obtaining a higher performance in relation to γ-alumina membrane. This reveals that the insertion of ZSM-5/γ-alumina in the material makes that this new material acquires a lower porosity, obtained by decreasing the passage of oil molecules through the membrane structure.

This work aimed to produce zeolite membranes MCM-22 using two methods of synthesis, dip coating (DC) and vapor phase transport (VPT), to be evaluated in the oil/water emulsion separation process. The membranes were prepared at 150 °C for 10 days and characterized by X-ray diffraction and scanning electron microscopy. They were evaluated in tests of pure water permeation and oil/water emulsion separation system of a synthetic effluent, using a stainless-steel module under the conditions of the initial concentration of the emulsion of 100 mg/L, temperature of 25 °C and pressure of 2.0 bar. The results showed that the MCM-22 zeolite membrane by DC had the final value of the permeate concentration of 3.2 mg/L and the membrane prepared by VPT presented a final value of 3.9 mg/L which were within the standards required by Resolution No. 392 of CONAMA which is up to 20 mg/L of mineral oils.

The hydrothermal synthesis of MCM-22 zeolite was carried out using silica, sodium aluminate and hexamethyleneimine, under static conditions at 150°C for a period of 10 days, followed by washing with deionized water, drying overnight and calcination at 650°C. The obtained material was characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The XRD analysis evidenced that MCM-22 presented a well defined MWW structure. The FT-IR spectrum confirmed the efficiency of the hexamethyleneimine as an organic template used to direct the structure of the MCM-22 zeolite under static conditions. The SEM image indicated that the particles are spherical in shape, with a diameter of ca. 10 µm. The acid properties of the MCM-22 zeolite, as determined by n-buthylamine adsorption, were investigated in the temperature ranges of 105 to 300°C and 300 to 525°C, relative to medium and strong acid sites, respectively.

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This study proposed the development of an efficient membrane composed of zeolite-alumina to be used for water-oil separation of wastewater effluents contaminated by oil extraction processes. The efforts made to care for the environment and to decontaminate bodies of water are extremely valuable and constantly being updated. Little research has been done on this subject and this study contributed to remedying this lack. Membrane technology is a reasonable alternative to conventional procedures if economics and eco-sustainability are considered. The objective of this study was to examine the performance of a composite membrane produced through mechanical mixing. The potential of the composite membrane (NaA zeolite/gama-alumina) to separate oil-water emulsions was tested. The results obtained demonstrated that the composite membrane is an excellent alternative for the oil/water emulsion separation process; the membranes are efficient and low-cost alternatives for treating oily wastewater.