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 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 method is provided for producing a high flux, high salt rejection cellulose acetate desalination membrane. In this method, cellulose acetate polymer is dissolved in a first solvent such as methylene chloride or 2-methyltetrahydrofuran to produce a solution. Further steps involve stirring the solution, and thereafter permitting the solution to settle, for a time sufficient for a majority of the cellulose acetate to precipitate out of the solution to form a cellulose acetate precipitate. Next, the cellulose acetate precipitate is stirred into an excess methanol. Thereafter, the cellulose acetate is filtered out and used in making the desalination membrane.

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

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

Abstract: A method is provided for producing a high flux, high salt rejection cellulose acetate desalination membrane. In this method, cellulose acetate polymer is dissolved in a first solvent such as methylene chloride or 2-methyltetrahydrofuran to produce a solution. Further steps involve stirring the solution, and thereafter permitting the solution to settle, for a time sufficient for a majority of the cellulose acetate to precipitate out of the solution to form a cellulose acetate precipitate. Next, the cellulose acetate precipitate is stirred into an excess methanol. Thereafter, the cellulose acetate is filtered out and used in making the desalination membrane.

Abstract: A chlorine resistant polyamide is formed from the reaction product of an amine and an acid chloride monomer wherein the acid chloride monomer is modified with electron-withdrawing groups that exhibit sufficient activity to (i) minimize any chlorination on both the amine and acid chloride side and (ii) minimize N-chlorination. A membrane is made from the polyamide and, in one application, the membrane is used 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: Aluminum alloys prepared from commercial grade aluminum and containing minor amounts of indium and zinc, useful as galvanic anodes, are improved by the addition of a small amount of silicon.