This article describes the synthesis of an analcime-C zeolite membrane on a ceramic support by in situ hydrothermal crystallization. A circular shaped ceramic support was firstly fabricated using low cost raw materials by a uni-axial pressing method and sintering process. Subsequently, the zeolite composite membrane was prepared with the repeated coating of analcime-C on the ceramic support through an in situ crystallization technique. The synthesized zeolite composite membrane was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), porosity, average pore size and pure water permeability. The influence of the number of coatings on the characteristics of the zeolite membrane was also explored. The obtained results clearly demonstrate that the porosity, pore size and water permeability of the membrane decrease significantly with the multiple coating of zeolite over the ceramic support. The porosity, average pore size and pure water permeability of the zeolite membranes are estimated to be 38-24%, 285-155 nm and 2.18 Â 10 À7 to 4.53 Â 10 À8 m 3 m À2 s À1 , respectively for various coatings (1-3). Finally, the separation performance of three times coated zeolite membrane was evaluated by removal of chromium(VI) from aqueous solution by ultrafiltration (UF) at various operating conditions (applied pressure, concentration and pH). The maximum rejection of 84% is achieved at an applied pressure of 207 kPa. Moreover, the separation performance of membrane is better as compared to other membranes reported in the literature.

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This study aimed to assess the performance of three zeolite membranes in the removal of trivalent metal ions from aqueous solution using a cross-flow mode of operation. Three types of zeolite membrane, MCM-41, MCM-48 and FAU, were prepared on a low-cost, circular ceramic support by hydrothermal treatment. The three zeolite membranes were characterized by using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and contact angle measurements. The XRD results confirmed the formation of zeolites. The deposition of zeolite on the ceramic support and hydrophilicity of zeolite membranes were monitored by FESEM and contact angle measurement, respectively. The pore size of the MCM-41, MCM-48 and FAU membrane was found to be 0.173 μm, 0.142 μm, and 0.153 μm, respectively, which was lower than that of the support (1.0 μm). The fabricated zeolite membranes were used to investigate the separation behavior of trivalent metal ions (Al 3þ and Fe 3þ ) from aqueous solution at various applied pressures. It was observed that an increase of applied pressure leads to a slight decrease in the removal efficiency. Among the various zeolite membranes, the FAU membrane showed the maximum rejection of 88% and 83% for Fe 3þ and Al 3þ separation, respectively.

This study deals with the separation of trivalent salts (FeCl3 and AlCl3) from aqueous solution using Faujasite (FAU) zeolite composite ultrafiltration membrane. The ceramic support was prepared by a facile uniaxial compaction method and sintered at 950°C. The FAU coating on the ceramic support was done at 75°C by hydrothermal method. The structural properties of FAU powder and the composite membrane were performed with X‐ray diffraction, zeta potential measurements, and field emission scanning electron microscope. The porosity of ceramic support and the composite membrane is found to be 47% and 33%, respectively. With the pure water permeation test, the average pore size of the FAU zeolite membrane and ceramic support is evaluated to be 0.153 and 1.0 µm, respectively. Finally, the FAU zeolite composite membrane is employed for separation assessment of trivalent salt solutions. A maximum rejection of 81% for FeCl3 and 75% for AlCl3 is obtained at an applied pressure of 276 kPa for the feed concentration of 250 ppm. © 2016 American Institute of Chemical Engineers Environ Prog, 35: 1047–1054, 2016