The present invention provides an apparatus and method for producing ultrapure water of extremely high purity that sufficiently meets the requirement for its quality at low production cost with reduced footprint. The apparatus for producing ultrapure water includes a pretreatment system, a primary water purification system, and a subsystem, wherein the primary water purification system includes a high-pressure reverse osmotic membrane separation unit, a degassing unit, an ultraviolet oxidation unit, and an ion-exchange unit in this order.

A process for ion-exchanging an exchangeable-ion containing solid material involves several steps. There is a bipolar membrane electrodialysis step, which involves subjecting an aqueous ion-containing solution to a bipolar membrane electrodialysis to produce an acid liquid. The process also contains an ion-exchange step, during which the exchangeable-ion containing solid material is contacted with the acid liquid to conduct ion-exchange to produce a slurry containing the ion-exchanged solid material. It further include a solid-liquid separation step, during which the slurry containing the ion-exchanged solid material is subject to a solid-liquid separation to produce a solid phase and a liquid phase. The pH value of the liquid phase is adjusted to 4-6.5. The pH-adjusted liquid phase is further subject to a solid-liquid separation to produce a treatment liquid.

A greywater recycling system for receiving, storing and recycling household waste influent, comprising: (a) a pre-filtration system comprising an open-ended transversal manifold placed in an elevated position, a series of micron-sized filters for collecting the influent, (b) a reservoir's storage system comprising: (i) a water level sensor for detecting the accumulated influent water level in a predetermined height, (ii) a pump, wherein the pump and the water level sensor are electrically connected together to automatically detect water level and activate or deactivate the pump, (c) the media housing filtration system comprising a series of filtration media for filtering out the effluent odor and contaminants, (d) an ultra-filtration system comprising the sub-micron sized filter, for sanitizing and purifying the outcome effluent, and (e) a check valve for adjusting effluent water pressure and directing the effluent flow direction.

Methods, systems and compositions for recovery of regenerant ions from spent regenerant solution by utilization of electrodialysis are provided. For example, in certain aspects methods for separating spent regenerant using an electrodialysis system comprising selective membranes are described. Furthermore, the invention provides methods for treating a friable solid ion-removal material to prevent fragmentation during regeneration.

The method for purifying oses from hemicellulose originating from lignocellulosic biomass includes eliminating the cellulose matrix and the solid residues and/or the suspended materials from the acid hydrolysate containing oses in order to obtain a clarified hydrolysate, and subjecting the clarified hydrolysate, without adding any basic chemical reagent to increase the pH to at least one step of ultrafiltration and/or to at least one step of nanofiltration, so as to obtain a filtrate containing the majority of the pentoses and a retentate containing the species likely to precipitate under the effect of an increase in the pH. The filtrate is treated by at least one step of electrodialysis so as to recover the acid catalyst from an acid-supplemented solution, and obtain a deacidified filtrate.

The method for purifying oses from hemicellulose originating from lignocellulosic biomass includes eliminating the cellulose matrix and the solid residues and/or the suspended materials from the acid hydrolysate containing oses in order to obtain a clarified hydrolysate, and subjecting the clarified hydrolysate, without adding any basic chemical reagent to increase the pH to at least one step of ultrafiltration and/or to at least one step of nanofiltration, so as to obtain a filtrate containing the majority of the pentoses and a retentate containing the species likely to precipitate under the effect of an increase in the pH. The filtrate is treated by at least one step of electrodialysis so as to recover the acid catalyst from an acid-supplemented solution, and obtain a deacidified filtrate.

A water treatment assembly (10) and method for its operation, comprising a spiral wound hyperfiltration membrane module (12) connected to: i) a feed line (14) adapted for connection to a source of pressurized feed water, ii) a permeate line (16) adapted for connection to a dispenser of treated water and iii) a concentrate line (18) adapted for connection with a drain; wherein the assembly includes a pressurizable reservoir (22) containing weak acid cation exchange resin (25) and further includes at least one valve for selectively diverting flow of pressurized feed water along the feed line (14), through the reservoir (22) and returning to the feed line (14) prior to passing through the hyperfiltration membrane module (12).

A water treatment assembly (10) and method for its operation, comprising a spiral wound hyperfiltration membrane module (12) connected to: i) a feed line (14) adapted for connection to a source of pressurized feed water, ii) a permeate line (16) adapted for connection to a dispenser of treated water and iii) a concentrate line (18) adapted for connection with a drain; wherein the assembly includes a pressurizable reservoir (22) containing weak acid cation exchange resin (25) and further includes at least one valve for selectively diverting flow of pressurized feed water along the feed line (14), through the reservoir (22) and returning to the feed line (14) prior to passing through the hyperfiltration membrane module (12).

A method for concentrating and crystallizing fermentable carboxylic acids, salts, and mixtures thereof may involve the use of carboxylic acids that have a defined temperature dependence of the solubility and of the osmotic pressure. The carboxylic acids may be concentrated by a membrane method and subsequently crystallized out by a cooling crystallization and isolated. In some examples, the membrane method may involve nanofiltration, reverse osmosis, and/or membrane distillation for separation into a concentrate and a permeate. Similarly, an apparatus for implementing such methods may include a nanofiltration, reverse osmosis, and/or membrane distillation unit for concentrating the carboxylic acid, and at least one cooling crystallization unit for crystallizing the carboxylic acid.”

A method for producing ultrapure water includes supplying raw water (industrial water, tap water, well water, or used ultrapure water discharged from semiconductor plants) to a pretreatment system for treating the raw water to produce water, supplying the water to a primary water purification system having a reverse osmosis membrane separation unit to produce a primarily purified water, and supplying the primarily purified water to a secondary purification system to produce ultrapure water.