Other

Seh America, Inc.

Debasish Mukhopadhyay

Allen R Boyce

Andrew J Bomber

Michael Ferrigno

A process for treatment of water. Hardness and non-hydroxide alkalinity are removed from feedwaters in amounts to substantially avoid scaling when concentrated. Sparingly ionizable components in the feedwater are urged toward increased ionization by increasing the pH of the feedwater, and, in an embodiment, up to about pH 10.5, or higher. In this manner, species such as silica become highly ionized, and (a) their rejection by membranes used in the process is significantly increased, and (b) their solubility in the reject stream from the membrane process is significantly increased. Sparingly ionized species such as boron, silica, and TOC are highly rejected, and thus, their passage through the membrane is reduced by a factor of ten or more. Recovery ratios of ninety percent (90%) or higher are achievable with many feedwaters, while simultaneously achieving a substantial reduction in cleaning frequency of membranes used in the process.

Method for high efficiency reverse osmosis operation

A process for treatment of water. Hardness and non-hydroxide alkalinity are removed from feedwaters to an extent sufficient to avoid scaling when concentrated. Sparingly ionizable components in the feedwater are urged toward increased ionization by increasing the pH of the feedwater. In this manner, species such as silica become highly ionized, and (a) their rejection by membranes used in the process is significantly increased, and (b) their solubility in the reject stream from the membrane process is significantly increased. Sparingly ionized species such as boron, silica, and TOC are highly rejected. Recovery ratios of ninety percent (90%) or higher are achievable with many feedwaters, while simultaneously achieving a substantial reduction in cleaning frequency of membranes used in the process.

High purity water produced by reverse osmosis. A feedwater is pretreated to remove hardness and non-hydroxide alkalinity, and the pH is raised to 8.5 or more to ionize solute species such as boron that are sparingly ionized when in neutral or near neutral pH aqueous solution. Ultrapure water resulting is suitable for industrial use.

High purity water produced by reverse osmosis

A process for treatment of water via membrane separation equipment. A feedwater is maintained or adjusted to a pH of 4.3 or lower, and fed to a membrane separation system. In this manner, species such as TOC become more ionized, and (a) their rejection by the membrane separation process is significantly increased, and (b) their solubility in the reject stream from the membrane process is significantly increased. Passage TOC through the membrane is significantly reduced. A recovery ratio of eighty percent (80%) or higher is achievable with most feedwaters, while simultaneously achieving a substantial reduction in cleaning frequency of the membrane separation equipment. The method is particularly useful for the preparation of high purity water.

Method and apparatus for treatment of feedwaters by membrane separation under acidic conditions

A process for treatment of water via membrane separation to remove hardness and non-hydroxide alkalinity by simultaneous removal in a weak acid cation exchange resin. The process includes ionization of sparingly ionizable components, such as silica, by adjusting the pH up to about 10.5 or higher. Their separation by the membrane is significantly increased. The passage of boron, silica and TOC is reduced by a factor of ten or more. Recovery of 90% or higher is achievable with most brackish feedwaters, while substantial reduction in cleaning frequency is simultaneously achieved. The apparatus used for the water treatment process includes reverse osmosis membrane(s) ( ), mixed bed ion exchange unit ( ), micron filter ( ), ultraviolet sterilization unit ( ), decarbonation unit ( ), and electrodeionization unit ( ).

Method and apparatus for high efficiency reverse osmosis operation

A treatment system for process exhaust streams containing NOx. The system includes a plurality of sequential scrubbing assemblies that collectively receive and contact a process exhaust stream containing NOx and a water stream to produce a product exhaust stream with a concentration of NOx that is below a determined threshold value. The removed NOx forms a portion of a system waste liquid stream that includes a majority of the NOx removed from the process exhaust stream.

Nox scrubbing system and method

A system and method for treating process gas streams containing isopropyl alcohol (IPA) to reduce the concentration of IPA therein. The invented system includes a scrubber unit that receives a process stream containing a concentration of IPA and reduces the concentration of IPA therein to below a determined threshold. The scrubber includes a reverse osmosis assembly that significantly reduces water consumption for the scrubbing process as compared to conventional once-through systems. The system may be operated at an elevated pH to prevent biofouling from inhibiting the operation of the reverse osmosis assembly. The system may contain a softening step on the make up water system to prevent scaling in the reverse osmosis system and a softening step on a sidestream of the scrubber water recirculation loop to reduce scrubber tower salting/scaling and to control the pH of the scrubbing liquid.

Isopropyl alcohol scrubbing system

A process for treatment of water via membrane separation equipment. Hardness and non-hydroxide alkalinity are removed from feedwaters to very low levels, preferably by simultaneous removal in a weak acid cation ion exchange resin. Then, ionization of sparingly ionizable components in the feedwater is substantially accomplished by increasing the pH of the feedwater preferably up to about pH 10.5, or higher. In this manner, species such as silica become highly ionized, and (a) their rejection by the membrane separation process is significantly increased, and (b) their solubility in the reject stream from the membrane process is significantly increased. Passage of weakly ionized species such as boron, silica, and TOC is reduced by a factor of ten or more. Recovery ratio of ninety percent (90%) or higher is achievable with most brackish feedwaters, while simultaneously achieving a substantial reduction in cleaning frequency. The method is particularly useful for the preparation of high purity water. Although the silica level in the reject water in this process is increased from the conventional range of approximately 150 ppm to a level of 450 ppm or better (thus increasing recovery rates), significantly improved levels of silica contamination in the ion-exchanged polished permeate are achieved. New Ultra Pure Water (UPW) systems utilizing this process will have thirty to fifty percent lower capital costs and at least twenty five percent lower operating costs compared to conventional UPW systems.

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Palo Alto, CA, United States of America

Debasish Mukhopadhyay