Abstract: An electrically-driven separation apparatus can be utilized to desalinate seawater and/or brackish water to provide irrigation water having a desired sodium adsorption ratio (SAR).

Abstract: An electrically-driven separation apparatus can be utilized to desalinate seawater and/or brackish water to provide irrigation water having a desired sodium adsorption ratio (SAR).

Abstract: A method and apparatus for purifying water are provided. A feed water such as seawater can be fed to a filter such as a microporous or nanofiltration membrane to produce a permeate that can, in turn, be fed to an electrodeionization system to produce fresh water.

Abstract: An electrically-driven separation apparatus can be used with a pressure-driven separation apparatus to provide potable water having a desired total dissolved solids (TDS).

Abstract: A low energy system and process for seawater desalination wherein the system has at least an electrodialysis apparatus that produces partially desalinated water and a brine by-product, an ion exchange softener, and at least one electrodeionization apparatus. The softener treats the partially desalinated water stream to remove or reduce the amount of scaling material in order to maintain deionization apparatus efficiency and reduce energy consumption. The softener has the capability of removing a higher ratio of calcium ions to magnesium ions than is in the partially desalinated stream, thereby reducing softener size and energy use. The deionization apparatus produces product water of the desired properties. The brine stream may be used to regenerate the softener.

Abstract: A low energy water treatment system and method is provided. The system has at least one electrodialysis device that produces partially treated water and a brine byproduct, a softener, and at least one electrodeionization device. The partially treated water stream can be softened by the softener to reduce the likelihood of scale formation and to reduce energy consumption in the electrodeionization device, which produces water having target properties. At least a portion of the energy used by the electrodeionization device can be generated by concentration differences between the brine and seawater streams introduced into compartments thereof. The brine stream can also be used to regenerate the softener.

Abstract: A method and apparatus for purifying water are provided. A feed water such as seawater can be fed to a filter such as a nanofiltration membrane to produce a permeate that can, in turn, be fed to an electrodeionization system to produce fresh water.

Abstract: A method and apparatus for purifying water are provided. A feed water such as seawater can be fed to a filter such as a microporous or nanofiltration membrane to produce a permeate that can, in turn, be fed to an electrodeionization system to produce fresh water.

Abstract: A membrane filtration module having a plurality of permeable, hollow membranes is disclosed. In use, a pressure differential is applied across the walls of the permeable, hollow membranes when immersed in a liquid suspension containing suspended solids. Some of the liquid suspension passes through the walls of the membranes to be drawn off as clarified liquid or permeate, and at least some of the solids are retained on or in the permeable, hollow membranes or otherwise as suspended solids within the liquid suspension. The module has a shell or similar structure that at least partially surrounds the membrane module and substantially effects retaining at least portion of fluid flowed into the membrane module.

Abstract: A method and apparatus for purifying water are provided. A feed water such as seawater can be fed to a filter such as a microporous or nanofiltration membrane to produce a permeate that can, in turn, be fed to an electrodeionization system to produce fresh water.

Abstract: An electrically-driven separation apparatus can be utilized to desalinate seawater and/or brackish water to provide irrigation water having a desired sodium adsorption ratio (SAR).

Abstract: An electrically-driven separation apparatus can be used with a pressure-driven separation apparatus to provide potable water having a desired total dissolved solids (TDS).

Abstract: A method and apparatus for evaluating a porous membrane. The method includes supplying a fluid to a first side of a wetted membrane at a pressure that is greater than the pressure on a second side of the membrane which is at a pressure greater than atmospheric pressure. The rate of transfer of the fluid from the first side to the second side is measured. The invention also includes an apparatus that includes a membrane mounted in a housing that divides the housing into a first compartment and a second compartment. A first fluid is contained in the first compartment at a pressure greater than the pressure in the second compartment. A second fluid is contained in the second compartment at a pressure greater than atmospheric pressure, and a measuring device is in communication with the first compartment, the second compartment, or both compartments.

Abstract: Electrodeionization apparatus and method. The electrodeionization apparatus includes an ion-depleting compartment in which alternating layers of an electroactive media are positioned. One of the alternating layers is doped to provide a more balanced current distribution through the apparatus. The method involves providing reducing the difference in conductivity between the alternating layers positioned in the ion-depleting compartment by adding a dopant material to one of the layers.

Abstract: A water treatment system and process for removing weakly ionized and/or organic materials from the water by intra-system pH adjustment. An exemplary embodiment of the system includes an inlet through which a feedstream passes into a first chemical treating unit wherein the pH of the feedstream is maintained below about 7 to substantially reduce a concentration of weakly basic components in the water by chemical conversion to a more ionized state. A first water treatment unit is positioned downstream of the first chemical treating unit to substantially remove ionized components in the stream, and produce a first product stream. In various embodiments, the first water treatment unit can be selected from the group consisting of a media filter unit, a water softener unit, a dechlorination unit, and combinations thereof.

Abstract: Electrodeionization apparatus and method. The electrodeionization apparatus includes an ion-depleting compartment in which alternating layers of an electroactive media are positioned. One of the alternating layers is doped to provide a more balanced current distribution through the apparatus. The method involves providing reducing the difference in conductivity between the alternating layers positioned in the ion-depleting compartment by adding a dopant material to one of the layers.

Abstract: A continuous electrodeionization apparatus and method. The continuous electrodeionization apparatus and method provide improved removal of weakly ionized ions, particularly silica. The apparatus and method involves using macroporous ion exchange resins that are both highly crosslinked and have a high water content. In preferred embodiments, the ion exchange resin beads also have a substantially uniform diameter.

Abstract: Electrodeionization apparatus and method. The electrodeionization apparatus includes an ion-depleting compartment in which alternating layers of an electroactive media are positioned. One of the alternating layers is doped to provide a more balanced current distribution through the apparatus. The method involves reducing the difference in conductivity between the alternating layers positioned in the ion-depleting compartment by adding a dopant material to one of the layers.

Abstract: An improved electrodeionization apparatus and method are provided. The electrodeionization apparatus includes electrolyte compartments, ion-concentrating, and ion-depleting compartments, having electroactive media therein. The electroactive media can be induced to have a reversible change in its chemical or electrical properties upon imposition of an external electrical field or the presence of an electrically charged substance. The change in chemical or electrical properties of the media results in a desired change in the transport or chemical properties of the media. The incorporation of the improved electroactive media also provides for an improved, and more reliable electrodeionization process in applications requiring chemical and temperature resistance media, where localized pH shifts would be harmful to the product being deionized, under temperature and chemical conditions of the liquid to be processed, or under circumstances where traditional media would tend to foul.

Abstract: An improved electrodeionization apparatus and method are provided. The electrodeionization apparatus includes an ion-concentrating compartment, an ion-depleting compartment, and electrolyte compartments, wherein alternating layers of anion exchange resins and cation exchange resins are positioned in the ion-depleting compartment, and the anion exchange resins comprise Type II anion resins. The incorporation of Type II anion material, alone or with Type I anion material, in anion permeable membranes and/or resins improves the electric current distribution, degree of resin regeneration, and deionization performance.