Abstract: A halogen resistant polyamide is formed from the reaction product of an amine monomer and an acid chloride monomer wherein the amino group of the starting amine monomer is separated from the aromatic amine ring system by an alkyl group and (i) minimizes halogenation on the amine and (ii) minimizes N-halogenation at a pH range of approximately 7 to approximately 10.5. A membrane is made from the polyamide for use, for example, in a reverse osmosis desalination unit.

Abstract: A chlorine resistant polyamide is formed from the reaction product of an amine and an acid chloride monomer wherein both the amine and the acid chloride monomer are modified with electron-withdrawing groups that exhibit sufficient activity to (i) minimize any chlorination on both the amine and acid chloride and (ii) minimize N-chlorination. A membrane is made from the polyamide for use, for example, in a desalination unit.

Abstract: A method of degassing a volume of supersaturated liquid is provided which comprises introducing a plurality of microbubbles of gas substantially near the bottom of the volume of supersaturated liquid so that the microbubbles percolate up through the volume of supersaturated liquid to thereby effect removal of dissolved gas in the volume of the supersaturated liquid at the top of the volume. In one embodiment, the step of introducing microbubbles comprises introducing the microbubbles by recirculating deionized water through a hollow fiber microfiltration membrane. In another embodiment, the step of introducing microbubbles comprises introducing the microbubbles through a pipe from the turbine of a dam. In most applications, the volume of supersaturated liquid is water and the microbubbles of gas comprise air. The volume of supersaturated water advantageously comprises a volume of a river, lake or stream which is near a dam with a turbine.

Abstract: A method is provided for producing L-ascorbic acid (Vitamin-C) in a single process step. Starting material, particularly a mixture of compounds from the group consisting of glucose, sorbitol, sorbose, and 2-keto-L-gulonic acid, is catalytically oxidized in aqueous solution by hypochlorous acid. L-ascorbic acid then can be separated from the aqueous solution, and the unconverted reactants recycled for greater conversion. The reaction occurs in the aqueous state at ambient temperature near a pH of 5.5 when an optimum amount of hydrous cobalt-oxide is present in the solution.

Abstract: A water denitrification process is provided which comprises stopping the reduction of nitrate at nitrite, lowering the pH of the water, and then gas stripping the nitrite out of the water by using air as the gas in a sparger. This allows considerable savings to be realized based on the reduced chemical removal costs as compared to other water denitrification processes.

Abstract: An ion exchange process utilizes a chemical system in which sodium nitrate is reacted with an acidic solution of urea to selectively precipitate nitrate ions from waste brine in the presence of chloride ions, thereby allowing for the recycling of the brine regenerant.

Abstract: Chemical-free autodecomposition of chlorine species to chloride ion and oxygen gas by contacting a chlorine containing liquid solution with a decomposition catalyst consisting of transition metals and their compounds in association with a high surface area per mass. The catalyst comprises Raney metals selected from the group including Raney Cu, Raney Ni, and Raney Co, and aluminum doped with transition metals selected from the group including vanadium, chromium, manganese, iron, cobalt, nickel, copper and zinc.

Abstract: An indicator device indicates that the temperature in a location in which the device is placed has exceeded a predetermined maximum temperature value. The he device includes a liquid receptacle comprising frangible bulb portion and an integral capillary portion and an absorbent card to which said receptacle is secured. The bulb portion contains a first liquid and the capillary portion contains a second liquid which is insoluble in said first liquid. The second liquid has a freezing point higher then that of the first liquid and close to but greater than the predetermined temperature value so that when the device is placed in a location which has temperature lower than the predetermined value and in which the predetermined value is to be maintained, the second liquid freezes in the capillary tube and prevents the first liquid from expanding.

Abstract: A chemical process for selectively removing organometallic compounds from water supplies. The process utilizes a combination of a transition metal selected from the group consisting of nickel, copper, iron and zinc, and an electropositive metal selected from the group consisting of magnesium and aluminum to effectively remove organometallic compounds from water whether present in ionic or non-ionic form.

Abstract: This invention concerns a method and apparatus for collecting and preserving field water samples on site in which a salt solution, contained in a syringe by a rupturable thin film membrane, is injected through a strong acid or base ion exchange filter to produce a required amount of either nitric acid, sulfuric acid or sodium hydroxide for sample collection and preservation.

Abstract: A chemical process for the catalytic oxidation of formaldehyde and other organic compounds contained in a dilute aqueous solution, particularly waste water. The inventive feature resides in the use of a cobalt catalyst, at ambient temperature, at a pH of 5.5, to increase the rate of oxidation of the organic compounds when hypochlorous acid is the oxidant. The latter may be provided by a chlorine compound, such as sodium hypochlorate, calcium hypochlorite or chlorine gas dissolved in water.

Abstract: A chemical process for selectively removing organoselenium compounds and selenate from water supplies. The process utilizes a combination of transition metal selected from the group consisting of nickel and copper and an electropositive metal selected from the group consisting of magnesium and aluminum to effectively remove selenium whether present in the water as organic or inorganic compounds or in ionic or non-ionic form.

Abstract: A chemical process for the denitrification of water comprising treating water with a metal sufficiently electropositive to decompose the water while regulating the pH within a range effective to permit efficient reduction of nitrate ion. The pH is regulated with alkali in a manner that avoids metal oxide formation and loss of metal by decomposition of water and results in the selective reduction of nitrate ion in the presence of sulfate and chloride ions.

Abstract: A method of selectively removing selenium ions from an aequeous solution containing selenium ions comprises contacting the solution with an amount of ferrous ion effective to reduce the selenium ions to elemental selenium. The contacting is preferably conducted at a pH of about 9 and the ferrous ions are preferably provided in situ in the form of ferrous hydroxide. The method may further comprise removing ferric oxides to which the ferrous ions are oxidized, these ferric oxides containing the elemental selenium produced by the reduction of the selenium ions, and separating the ferric oxides from the elemental selenium by adding a strong acid thereto.