Desalination methods that include carbonate compound precipitation are provided. In certain embodiments, feed water is subjected to carbonate compound precipitation conditions prior to desalination. In certain embodiments, desalination waste brine is subjected to carbonate compound precipitation conditions. In yet other embodiments, both feed water and waste brine are subjected to carbonate compound precipitation conditions. Aspects of embodiments of the invention include carbone dioxide sequestration. Embodiments of the invention further employ a precipitate product of the carbonate compound precipitation conditions as a building material, e.g., a cement. Also provided are systems configured for use in methods of the invention.

Desalination methods and systems that include carbonate compound precipitation

Preparation and characterization of polypiperazine amide/PPESK hollow fiber composite nanofiltration membrane

An asymmetrical, microporous, hollow fiber membrane is made from a polymeric dope mixture of polysulfone and polyvinyl pyrrolidone dissolved in an aprotic solvent. The physical morphology of the hollow fiber membrane, i.e., the asymmetric microporous wall, is rapidly formed by passing the polymeric dope mixture through an outer annular orifice of a tube-in-orifice spinneret while simultaneously passing a precipitating solution through the central tube of the spinneret. The emerging hollow fiber travels substantially downward for about 0.01-10 m before submersion into a quenching bath. The asymmetrical, microporous, hollow fiber membrane is biocompatible and suitable for use in, for example, dialysis, hemodialysis, ultrafiltration, and water filtration applications.

Hollow fiber membranes and method of manufacture

Microporous membranes can be prepared which comprise a polymer which is a hydrophobic polymer in bulk form and which has an equilibrium water absorption from about 2% to about 4%, but is hydrophilic when precipitated as a membrane. The membranes are further characterized by high water flow rates at any given bubble point.

Filtration membranes and method of making the same

Thin-film composite hollow fiber membranes: An optimized manufacturing method

A composite lumen-side feed reverse osmosis membrane and its preparation are disclosed, the membrane comprising a polymeric microporous-walled hollow fiber support with an interfacially-polymerized ultrathin semipermeable salt-rejecting layer engrafted on the lumen or bore of the hollow fiber support, the support having walls that are substantially completely free of finger-like voids in excess of about 5 microns in the area of the wall adjacent the lumen. The preparation of the support comprises coaxially spin-casting (1) a fiber-forming solution containing a pore-forming material with (2) a lumen-forming fluid comprising from about 50 to about 70 vol % organic solvent in water.

Composite membrane for reverse osmosis

A reverse osmosis composite membrane is in the form of a hollow fibre which provides support. Its inner surface defines a lumen extending along the interior of the fibre and having a dia. of 0.125-1.25 mm. An interfacial salt-rejecting membrane is coated on the inner fibre surface. The wall of the fibre is microporous but free of voids visible at 100 x magnification in the region surrounding and including said surface. Desalination of brackish water, which is fed to the lumen of the fibres. The fibres can withstand the internal pressures and the composite membrane has good salt rejection with high flux rate.

Richard William Baker

Papers

Composite membrane for reverse osmosis

Reverse osmosis composite membrane is hollow fibre - whose inner surface is coated with interfacial salt rejecting membrane