Abstract: The present invention is directed to methods for using an improved reverse osmosis membrane that shows surprisingly improved solute rejection and permeation properties. The membrane includes a separating layer of a polyamideurea formed in situ by reaction of isocyanate-substituted acyl chloride and a diamine-treated microporous substrate.

Abstract: Non-brackish water can be produced from the brackish water found in many inactive oil wells. The inactive well is perforated at the level known to have brackish water and the water is pumped out. The brackish water is desalinated producing non-brackish water, preferably, potable water. A preferred method of desalination is by reverse osmosis.

Abstract: A volume reduction process comprises combinations of a freezing eutectic, bulk, indirect crystallization process and a radwaste electrodialysis process. When employed as a liquid radioactive waste management system (LWMS) for light water reactors (LWR's), this process is designed to process liquid low-level radioactive waste (LLW) and to handle the radioactive influent in nuclear power plants (NPPs) prior to release to the environment and disposal of the radioactive material present in the waste streams.

Abstract: Desalination of water is effected by use of a polyimine membrane which has been cross-linked with a combination of aliphatic and aromatic polyisocyanate or with a polycarbonyl chloride cross-linking agent.

Abstract: Composite membranes are provided comprising an underlying membrane selected from the group consisting of microfiltration, ultrafiltration and reverse osmosis membranes; and a coating thereon comprising at least one member selected from the group consisting of polyaromatic polymers and sulfonated poly(haloalkylenes), which has been subjected to a post-coating crosslinking treatment. These coated membranes are useful for various separation processes, especially in the food industry.

Abstract: Semipermeable membranes comprising polyesters which are resistant to chlorine are prepared by casting on a porous support backing material either a solution comprising a blend of a polymeric hydroxyalkyl acrylate and a polymeric monocarboxylic acid, or a polymeric polycarboxylic acid, or a solution containing a prepolymer which has been formed by the reaction of a polymeric hydroxyalkyl acrylate with an acryloyl halide or an anhydride of a dicarboxylic acid. The porous support backing material is contacted with the solution at contacting conditions, following which the excess solution is removed and the solution-coated porous support backing material is then cured at curing conditions. This membrane will possess excellent characteristics of salt rejection and flux as well as being resistant to the action of chlorine which is present in water which is subjected to a desalination process.

Abstract: The invention is directed to an energy recovery pump turbine for use in industrial processes where a fluid is pumped at a high pressure to the process and at least a portion of the fluid is discharged from the process at a high pressure. A turbine is positioned to receive the high pressure discharge from the process. The turbine has an impeller positioned on a shaft and the discharged fluid engages the impeller and causes the impeller and shaft to rotate. A pump is position adjacent to the turbine to receive the fluid being pumped to the process. The pump has an impeller mounted on a shaft and the shaft of the pump is operatively connected to the shaft of the turbine. Rotation of the turbine shaft causes the impeller and the shaft of the pump to rotate whereby the pump assists in supplying the fluid under pressure to the process and to recover energy from the high pressure fluid discharged from the process.

Abstract: A membrane pouch, for rehydrating sterile intravenous and other solutions for non-sterilized fresh water, has a double bag construction. An inner bag made of semipermeable membrane material holds the sterile solutes to be rehydrated. The membrane material is permeable by water but impermeable to contaminants and a large molecular weight solute contained in the bag. An outer waterproof bag encloses the membrane bag and serves as a container for fresh water. Each bag has a sealable valve for providing access to the interior thereof. A high molecular weight dye located in the outer bag provides a visible indication of the existence of any discontinuity in the membrane bag. A low molecular weight, water soluble, non-toxic substance having a high osmotic pressure can be placed inside the membrane bag to accelerate the osmotic transfer of sterile water from the outer bag into the inner membrane bag.

Abstract: Method of crystallizing from aqueous solution an inorganic solute, whose solubility in water varies relatively litter with temperature such that crystallizing by adjustment of temperature results in low yield, such method comprising contacting a concentrated aqueous solution of the solute with a hydrophilic organic solvent at a temperature T.sub.1, T.sub.1 and the organic solvent being selected such that at T.sub.1 a water-rich phase is formed in which the ratio of solute to water is less than the ratio found in the incoming aqueous solution, resulting in formation of crystals of solute. The resulting wet, organic-rich phase is separated and dried by contact with a concentrated aqueous solution of the solute at T.sub.2. T.sub.2 differs from T.sub.1, preferably being less than T.sub.1 if the solute dissolves exothermically in water and preferably being greater than T.sub.1 if the solute dissolves endo- thermically in water. The resulting dried organic phase is recycled to the crystallizing zone.

Abstract: A hydrophobic semi-permeable membrane process (e.g., using hydrophobic microporous hollow fibers) for the concentration of a dilute solution of low osmotic pressure by osmotic distillation (also known as membrane distillation or membrane evaporation), which is a separation process using as its driving force the difference in the osmotic pressure between two fluids (e.g., fruit juice and seawater) separated by a hydrophobic semi-permeable membrane to achieve a concentration of the fluid having the lower osmotic pressure (.e., fruit juice). When coupled with reverse osmosis means there is provided a method for recovery of solvent (e.g., potable water) from the process, e.g., desalination of seawater. A process is also provided to recover part of the energy available between the two fluids i.e., between two different potential energies, due to the difference in osmotic pressure between the two fluids.

Abstract: A process is provided wherein dissolved salts are selectively extracted from aqueous saline media by contacting the aqueous media with a solvent comprising a water insoluble organic diluent such as kerosene and a surfactant capable of effecting a preferntial transfer of solubilized salts in the aqueous media into the non-aqueous phase.

Abstract: Method of treating an aqueous solution of a non-volatile inorganic solute to produce a more concentrated solution or to crystallize solid solute from the solution. The solution is contacted at a higher temperature T.sub.1 with a suitable organic liquid to extract water and form an organic phase (organic liquid contacting water). The organic phase, separated, cooled and contacted at a lower temperature T.sub.2 with a drying medium to dry the organic liquid which is then re-used to treat a further quantity of aqueous solution. The drying medium may be a portion of the concentrated aqueous solution resulting from the first step, or it may be a concentrated aqueous solution or a slurry from an outside source, or it may be a combination of two such drying media.

Abstract: The invention describes a new separation technique which leads to multi-stage operations by the use of a series (a cascade) of alternated carrier-containing supported-liquid membranes. The membranes contain alternatively a liquid cation exchanger extractant and a liquid anion exchanger extractant (or a neutral extractant) as carrier. The membranes are spaced between alternated aqueous electrolytic solutions of different composition which alternatively provide positively charged extractable species and negatively charged (or zero charged) extractable species, of the chemical species to be separated. The alternated aqueous electrolytic solutions in addition to providing the driving force to the process, simultaneously function as a stripping solution from one type of membrane and as an extraction-promoting solution for the other type of membrane.

Abstract: Method of concentrating aqueous solutions of non-volatile, ionic solutes by extracting water from the solution by means of a polar organic liquid (or a solution of a polar organic liquid and a non-polar organic liquid) at an elevated temperature and cooling the organic liquid to separate a water phase, the extractant and the temperatures being chosen such that water has a relatively high solubility in the extractant at the higher temperature and a relatively low solubility at the lower temperature; the extractant being also chosen to meet certain other criteria such as inertness toward the solution and equipment. Advantage is taken of the diminished activity coefficient of water in polar organic liquids at elevated temperatures and in the case of certain solutions, advantage is also taken of the increased activity coefficient of water in aqueous ionic solution at elevated temperatures.

Abstract: Inorganic salts are removed from an unpotable water stream, which contains suspended living microorganisms and their debris products, particularly seawater or agricultural field drainage water. Chemicals such as caustic soda and/or chlorine, and derivatives therefrom, sterilize the water and remove from it certain dissolved and suspended constituents. From the sterilized water is separated a more concentrated stream of waste brine containing debris and other suspended materials, and most of the dissolved sodium chloride. From the remaining portion of the water is separated a more concentrated stream of sodium chloride, which is electrolized to provide a source of caustic soda, chlorine, and derivatives therefrom; the less concentrated portion is recovered as a source of potable water.

Abstract: Method and apparatus for making separations from aqueous solutions, particularly for removing water from aqueous solutions of electrolytes or other substantially non-volatile solutes, such as saline water. According to the invention, a solvent extraction process is employed which produces streams of lower and higher solute concentration in composition from an aqueous solution by contacting the aqueous solution with a solvent to produce an extract stream and a residual raffinate stream, the solvent having the property of dissolving water at a first lower temperature and substantially releasing it at a second higher temperature without substantially extracting the solute from the aqueous solution. The extract stream is contacted with a hotter aqueous reflux and thereby simultaneously heated and caused to have its content of undesired solute diminished.

Abstract: Separation of certain water soluble organic monomers such as acrylic acid from an aqueous solution can be accomplished by extraction with carbon dioxide, crystallizing the extract to remove carbon dioxide hydrate, and flashing off the remaining carbon dioxide solvent from the extract.