An object of the present invention is to provide a desalination apparatus in which a high pressure pump can be operated at a high efficient operation point even when temperature, salt concentration or the like of water to be treated vary. The desalination apparatus includes a high pressure pump which is provided in a first flow path and supplies raw water to a first module at high pressure to apply reverse osmotic pressure to a first module and a second module, a third flow path for supplying second concentrated water after separation in the second module to upstream of the high pressure pump in the first flow path, and a fourth flow path for supplying a portion of the first concentrated water after separation in the first module to upstream of the high pressure pump in the first flow path.

Systems and processes for purifying and concentrating a liquid feed stream are disclosed. In the systems, the concentrated liquid output from the high pressure side of a reverse osmosis stage is used as the draw solution in the low pressure side of the reverse osmosis stage in a configuration called osmotically assisted reverse osmosis. This reduces the osmotic pressure differential across the membrane, permitting high solute concentrations to be obtained, hastening the purification of the liquid. Reduced system pressures are also obtained by arranging multiple osmotically assisted reverse osmosis stages in a cross-current arrangement. Overall system energy consumption is reduced compared to conventional thermal processes for high concentration streams.

Embodiments described herein relate to methods and systems for dewatering alcoholic solutions via forward osmosis.

An apparatus, system and method to purify water is disclosed. In addition, the apparatus, system and method can effectively discharge the brine effluent. The apparatus can comprise an offshore structure, wherein the offshore structure comprises a water intake device connected to a pre-desalination filters connected to a plurality of reverse osmosis filters in communication with a purified water line and effluent discharge device. A plurality of filters for filtering the water from the intake, filter the water to remove solid contaminated before running the filtered water through the reverse osmosis system to the discharge device and purified water lines. Herein also disclosed is a wastewater discharge system. In an embodiment, the system comprises a control panel that controls, the offshore structure plurality of filters, plurality of reverse osmosis filters, purified water line and effluent discharge device, to achieve favorable water purification. Herein also described is a method that utilizes the apparatus and/or system disclosed herein. In an embodiment, the method comprises: obtaining an offshore structure comprising a water purification system, flowing water into an inlet device, pumping the water through a filtration system, flowing the filtered water through a plurality of reverse osmosis filters; flowing purified water through a purified water line; and flowing discharge effluent through a discharge device.

Provided are an apparatus for removing boron and a method for removing boron for reducing the boron concentration in water to be treated, and an apparatus and a method for producing pure water wherein the boron concentration is reduced. An apparatus for removing boron includes: a first electrodeionization device to which water to be treated is supplied; an ultraviolet oxidation device to which the water treated by the first electrodeionization device is supplied; an oxide removal device to which the water treated by the ultraviolet oxidation device is supplied; and a second electrodeionization device to which the water treated by the oxide removal device is supplied. A method for removing boron using the apparatus is provided. The oxide removal device is equipped with a platinum group metal catalyst, and the water that has been treated by the oxide removal device has a hydrogen peroxide concentration of less than 1 ppb.

A reverse osmosis treatment device includes: a first pressure vessel for treating an untreated water to produce a primarily treated water and a first permeated water; a second pressure vessel for treating the primarily treated water to produce a secondarily treated water and a second permeated water; a first cleaning solution tank for storing a first cleaning solution for cleaning the first pressure vessel; and a second cleaning solution tank for storing a second cleaning solution for cleaning the second pressure vessel. Each of the first pressure vessel and the second pressure vessel has therein a reverse osmosis membrane element having a reverse osmosis membrane. The first cleaning solution tank is connected to the first concentrate outlet pipe of the first pressure vessel, and the second cleaning solution tank is connected to the inlet pipe for the primarily treated water of the second pressure vessel.

A system and method for producing minerals from divalent ion-containing brine stream includes rejecting sulfate from a divalent-ion rich reject stream in a first nanofiltration seawater reverse osmosis (NF-SWRO) unit, producing solid calcium sulfate dihydrate and a magnesium-rich brine stream in a first concentration unit, concentrating the magnesium-rich brine stream to a saturation point of sodium chloride in a second concentration unit, producing solid sodium chloride and a supernatant product stream in a first crystallizing unit, produce a concentrated magnesium-rich bittern stream from the supernatant product stream in a third concentration unit, and at least one of producing hydrated magnesium chloride from the concentrated magnesium-rich bittern stream in a second crystallizing unit and producing anhydrous magnesium chloride by prilling the concentrated magnesium-rich bitterns stream under a hydrogen chloride atmosphere in a dry air process unit.

A filtering device is for obtaining a chemical liquid by purifying a liquid to be purified, and has an inlet portion, an outlet portion, a filter A, at least one filter B different from the filter A, and a flow path which includes the filter A and the filter B arranged in series between the inlet portion and the outlet portion and extends from the inlet portion to the outlet portion, in which the filter A includes at least one kind of porous membrane selected from the group consisting of a first porous membrane having a porous base material made of polytetrafluoroethylene and a non-crosslinked coating which is formed to cover the porous base material and contains a perfluorosulfonic acid polymer and a second porous membrane containing polytetrafluoroethylene blended with a perfluorosulfonic acid polymer.

Liquid solution concentration methods and related systems involving osmosis units and energy recovery are generally described. In some embodiments, an osmotic system has a pump, a first reverse osmosis unit, a second reverse osmosis unit, and one or more energy recovery devices. Various embodiments are directed to features such as balancing streams, recirculation streams, and/or valving that alone or in combination may afford improved energy efficiency and/or system performance. Some embodiments may improve performance of certain types of energy recovery devices in combination with osmosis units, such as isobaric or turbine energy recovery devices.

Methods and systems for producing urea are provided. Ammonia, carbon dioxide, and a carbamate solution can be combined in a pressurized mixer to produce a carbamate reaction mixture. The carbamate reaction mixture can be transferred from the pressurized mixer to a reactor. The carbamate reaction mixture can be heated in the reactor to produce a urea reaction mixture that can include urea, water, ammonia, carbon dioxide, and ammonium carbamate. The urea reaction mixture can be contacted to a membrane to separate an aqueous filtrate and a urea concentrate that can include urea, ammonia, carbon dioxide, and ammonium carbamate. The urea concentrate can be transferred from the reactor to a urea purification system that can include one or more separators and one or more decomposers. The urea concentrate can flow through the urea purification system to produce one or more urea products and one or more carbamate solutions.