Abstract: The process of producing a reverse osmosis membrane by the steps of preparing a liquid mixture of N-vinyl pyrrolidone, maleic anhydride and maleimide, wetting a porous membrane with the mixture and irradiating the wetted membrane with laser energy with energy sufficient to polymerize the mixture to form a terpolymer of N-vinyl pyrrolidone, maleic anhydride and maleimide on the membrane.

Abstract: A process for improving the separation rate of water from a stream of aqueous caffeine and coffee bean extract by reverse osmosis by adding to the stream an effective amount of polyvinylpyrrolidone.

Abstract: A method of removing foulants from spiral-wound reverse osmosis cartridges, comprising the steps of:a) freeing the envelopes and webbing from their original confinement;b) soaking the envelopes and webbing in a cleaning solution, specific to the general chemical nature of the foulants found in the webbing and on the surface of the envelopes, for a period of time sufficient to dissolve solubilize soften, and loosen the foulants;c) unwrapping and washing each membrane envelope and layer of webbing to physically remove the foulants therefrom;d) rewinding the membrane envelopes and layers of webbing in spiral configuration about the center product tube while simultaneously drawing a vacuum on the product tube to remove air trapped in the envelopes and enable the memory of the envelopes and webbing to urge themselves into their original tightly-wrapped configuration thereabout; and,e) reconfining the ends of the wrapped layers and resealing the outer surface and one end of the reassembled cartridge against leakage