Preparation of nanopore MFI zeolite membranes for water Desalination

فاقد چكيده

The zeolite membranes were extensively researched for many industrial separations via gas permeation and liquid pervaporation processes. General separation mechanisms in zeolite membranes include molecular sieving and competitive adsorption and diffusion. Recently, possibility of using zeolite membranes to remove ions from aqueous solutions by reverse osmosis (RO) has been explored. RO desalination by zeolite membranes may offer an alternative for some difficult water treatment processes such as concentration of low-level radioactive wastewater and desalination of high-concentration organic water produced in oil and gas operations, where the conventional technologies, including polymeric RO membranes, are either inapplicable or inefficient. The MFI-type zeolite has an effective intracrystal pore diameter of 0.51 nm, which is smaller than the sizes of hydrated ions involved in the current systems. As a result, complete rejection of hydrated ions can occur using MFI-type zeolite membranes. In this research, mullite supported MFI-type zeolite membranes were synthesized via insitu crystallization method. Hydrothermal treatment was conducted in an autoclave at an autogenously pressure. The membranes were fabricated by a single hydrothermal treatment and characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM) after calcinations.