Desalination with Novel Ceramic Reverse Osmosis Membranes

Polymeric reverse osmosis membranes are widely used for water and wastewater purification. However, their lack of chemical and especially oxidant (chlorine, oxone) stability, susceptibility to fouling, poor storage/shelf life, and a variety of other disadvantages has limited their effectiveness. By comparison, ceramic membranes display a number of materials advantages over polymeric. Of particular importance in RO applications is the excellent resistance to chlorine, oxidants, radiation, and solvents; the high thermal and pressure stability; and the long reliable life of ceramic membranes. Hence, unlike polymeric membranes, the basic physiochemical properties necessary to produce high quality RO membranes are available from the outset with ceramic materials. However, up to now their excessive cost and limited performance capabilities in RO type applications has halted successful introduction of this type of technology. Recently, Media and Process Technology, Inc. has developed a low cost molecular sieving ceramic membrane in a composite hollow fiber configuration. This membrane has demonstrated NaCl rejections of >50% at fluxes comparable to commercially available nanofiltration/reverse osmosis membranes. In this Phase I effort, modifications to the current membrane deposition technique will be developed to deliver NaCl rejections of 95 to 99%. Additionally, storage life, oxidant stability, and fouling resistance will be examined. The commercial potential for a low cost ceramic based reverse osmosis (and nanofiltration) membrane is tremendous. All of the physiochemical limitations of commercially available polymeric reverse osmosis membranes can be overcome with this innovative new product. Hence, not only are the more routine applications accessible by this technology, but applications in exotic high temperature, aggressive solvent, radioactive, etc. Environments can now be considered.