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: Inorganic salts are removed from an unpotable water stream, particularly a salt-containing inland water stream. The stream is passed sequentially through anion and cation exchange beds. Periodically the anion exchange bed is regenerated with sodium hydroxide and the cation exchange bed with hydrochloric acid to form spent regenerant streams which are combined with hydrochloric acid in the presence of calcium ion to precipitate calcium salts of anions from the mixture. The soluble portion is then mixed with sodium hydroxide in the presence of carbonate ion to precipitate insoluble cations from the mixture as hydroxides or carbonates. The soluble portions, comprising essentially an aqueous sodium chloride stream, is separated into a more concentrated and less concentrated portion. The more concentrated stream is electrolyzed to provide a source of hydrochloric acid and sodium hydroxide for the above steps, while the less concentrated stream is recovered as a source of potable water.

Abstract: Water which contains contaminants such as brine may be subjected to a desalination process and made potable thereby by treating the water in a reverse osmosis and ion exchange system, the heat which is present in the water source being utilized to thermally regenerate the ion exchange resin.

Abstract: Ground water which is high in impurity content such as silica, hardness, sulfates, alkalinity, etc., may be made potable by treating the water with thermal ion exchange desalination resins and a reverse osmosis system. The heat which is present in the ground water is utilized to thermally regenerate the ion exchange resin.