Our patent pending technology is based on a deposition technique to adhere Polydopamine, a highly hydrophilic polymer onto the surface of commercial membranes. The technology allows modification of all wetted parts, including membranes, housing, spacers and the module by simply flowing a specialized solution through the module. The ease of coating method allows modification of existing membrane systems without any additional infrastructure. Polydopamine deposition is possible on variety of membranes, including but not limited to Polysulfone ultrafilteration, Polyamide reverse osmosis and Nanofiltration, Polypropylene microfiltration and Polytetrafluoroethylene microfiltration membranes. Lab data has shown 30-50% improvement in anti-fouling properties of the commercial membranes while maintaining the flux performance.
There are many general water purification technologies available, each of which has a relatively specialized application. These include activated carbon filters for removal of organic compounds and chlorine, ultraviolet radiation and chlorine treatment for sterilization of microorganisms such as bacteria and viruses, distillation for separating water from nonvolatile contaminants, and deionization (or ion exchange) for desalination. However, none of these technologies has the capability to completely purify water by itself (i.e., carbon filters cannot remove bacteria or ions from water, distillation cannot separate some volatile organic compounds from water, UV cannot kill cysts and does not remove any other contaminants, etc.).
Membranes are an attractive solution to water purification based on their versatility (i.e., membranes can remove nearly all water contaminants), small environmental and spatial footprint and inherent economic advantages over alternative technologies. One of the major road blocks to widespread use of membranes for water purification is membrane fouling. Fouling occurs when certain impurities in water deposit on a membrane’s surface or in its internal pore structure. This deposition leads to a dramatic reduction in water flux, which increases operating costs and decreases membrane lifetime. Therefore, a new material which could be coated on existing membranes or new membrane materials are needed in the marketplace. Our technology addresses this need by providing a coating technology for existing membranes. Furthermore, as fouling is seen on multiple parts of a membrane module, such as the membrane housing and membrane spacers. Modification of these vital parts are also achieved during the flow-through process while treating the membranes for enhance fouling resistance.
