Abstract: A process for treatment of acidic waters 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 total organic carbon (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 of total organic carbon (TOC) through the membrane is significantly reduced. A recovery ratio at or exceeding eighty percent (80%) 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.

Abstract: 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.

Abstract: 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.

Abstract: 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) (30), mixed bed ion exchange unit (44, 46), micron filter (48), ultraviolet sterilization unit (49), decarbonation unit (20), and electrodeionization unit (150).

Abstract: 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.

Abstract: Unique ultrapure water produced by reverse osmosis equipment. The high purity or ultrapure water is characterized by extremely low levels of Total Organic Carbon that are achieved after a single pass reverse osmosis process step. The feedwater to the reverse osmosis process is preferably pretreated 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. The passage of boron, silica, and TOC is therefore significantly reduced. Consequently, the high purity water is produced with high recovery rates from the entering feedwater. Therefore, a unique ultrapure water product is provided that significantly reduces costs for post-treatment in downstream polishing steps.

Abstract: A process for treatment of water via memhrane separation to remove hardness and nonhydroxide alkalinity by simultaneous removal in a weak acid cation exchange resin. The process includes ionization of sparingly ionizable componients, 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, At hue substantial reduction in cleaning frequency is simultaneously achieved.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An apparatus and method for treating streams containing cyanide, heavy metal and precious metal values to recover those values where the method includes the following steps:a) providing a membrane filtration means having an inlet, a product outlet and an discharge outlet,b) contacting the waste stream to be treated with an effective amount of carbon dioxide to adjust the pH to about 8.0 to about 10.0,c) further contacting the waste stream with an effective amount of a soluble metal compound to react with the cyanide in the waste stream to form membrane rejectable cyanide compounds, andd) passing the treated stream through the membrane filtration means to thereby separate recoverable cyanide and precious metal values from the treated stream and produce an effluent stream for further processing or discharge to the environment.