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.

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.

A membrane process unit (MPU) is configured to receive a feed stream, subject the feed stream to membrane purification to generate a product stream and a concentrate stream, and subject the concentrate stream to energy recovery to provide at least a portion of energy for membrane purification. A concentrate recycle unit (CRU) is configured to receive the concentrate stream from the MPU, subject the concentrate stream to flow regulation to generate a waste stream and a recycled concentrate stream, and combine the recycled concentrate stream with a raw feed stream to generate the feed stream which is supplied to the MPU. At least one of a flow rate of the raw feed stream, a flow rate of the waste stream, or a flow rate of the recycled concentrate stream is varied, while each of a flow rate of the feed stream, a flow rate of the product stream, and a flow rate of the concentrate stream is maintained substantially fixed.

A portable water collection, filtration and power generation system is provided. The system is comprised of a holding tank, a filtration system, a reverse osmosis system an electrical power generator a mobile transport unit that holds the holding tank, filtration system, reverse osmosis system, and the electrical power generator. The holding tank is configured to receive water from a water source. The filtration system is fluidly coupled to the holding tank and includes an input configured to receive water from the holding tank, a filter disposed in fluid communication with the input, and an output to configured to discharge filtered water from the filtration system. The reverse osmosis system is fluidly coupled to the filtration system. The reverse osmosis system includes an input configured to receive filtered water from the filtration system and an output to configured to discharge reverse osmosis water. At least one electrical power generator is electrically coupled either the filtration system or the reverse osmosis system.

Separation systems are described that may include forward osmosis (FO) membranes for offshore desalination and sulfate removal. The system may use submerged FO elements (e.g. operating underwater in the ocean). The system may use FO elements in combination with high-pressure reverse osmosis (RO) elements and processes. The system may use FO elements in combination with membrane distillation elements and processes. The system may create a suction and pressurized flow from a submerged FO membrane process to a reverse osmosis system on a platform, ship, or other offshore or “along shore” structure. The product water may be used for enhanced oil recovery (EOR).

An ocean wave-driven sea water desalination plant employs ocean bottom mounted and hinged flaps driven in oscillating motion by wave surge force to drive rotary pumps which directly pressurize filtered sea water for use by a reverse osmosis (RO) plant and a hydraulic motor-generator set which provides electrical power to RO plant peripheral devices. Means are provided to control the filtered sea water pressure presented to the RO membranes to a preferred set point value. Means are also provided to control the pump reaction torque presented to the flap independently of water pressure by adjusting the effective pump displacement with a pulse width modulated valve shunting the pump ports to maximize captured wave power. Control of pump reaction torque may be effected slowly according to average sea state conditions or in real-time to further enhance captured wave power.

Provided is a reverse osmosis treatment apparatus which decreases operation power by utilizing a back pressure caused by regulating an amount of permeated water. The reverse osmosis treatment apparatus includes a first pressure vessel for a primary treatment of untreated water, and a second pressure vessel for a secondary treatment of the water treated by the primary treatment, wherein a reverse osmosis membrane element having a reverse osmosis membrane or the plurality of reverse osmosis membrane elements are arranged in series along a water collection pipe in the first pressure vessel and the second pressure vessel. The first pressure vessel includes a first outlet pipe which discharges permeated water, and a permeated water flow control valve connected to the first outlet pipe and regulating a pressure in the first pressure vessel. An energy recovery apparatus is provided between the first outlet pipe and the permeated water flow control valve.

An apparatus, system and method to purify water is disclosed. Pumps and energy recovery devices for taking water from an intake, filtering the water to remove solid contaminates before running the filtered water through the reverse osmosis system to the discharge device and purified water lines are described. The system may comprise a control panel that controls the plurality of filters, plurality of reverse osmosis membranes, purified water line and effluent discharge device, to achieve favorable water purification. A method that utilizes the apparatus and/or system is described herein.

A source liquid including a solvent with a dissolved impurity flows into a reservoir. The source liquid or a concentration of the source liquid is pumped from the reservoir through a pressure exchanger into an upstream side of a liquid-separation module. The module includes a membrane that at least partially purified solvent as filtrate to a permeate side of the liquid-separation module while diverting the impurity in a feed retentate on the upstream side of the liquid-separation module. The substantially pure water is extracted from the permeate side of the liquid-separation module, while the feed retentate is passed from the upstream side of the liquid-separation module through the pressure exchanger, where pressure from the feed retentate is transferred to the feed from the reservoir. The feed retentate is then passed from the pressure exchanger to the reservoir and recirculated as a component of the feed via the above steps.