A desalination system including: a partitioned container having upstream and downstream compartments divided by a movable partition, a first inlet port at an upstream end, and a second inlet port and an outlet port at the downstream end; a membrane container housing a cross-flow semipermeable membrane dividing the membrane container into saline and desalinated compartments, the saline compartment including first and second cross-flow ports, the desalinated compartment including a desalinated water outlet port; a feed pump connected to the first inlet port; a recharge pump having an inlet connected to the second cross-flow port and an outlet connected to the second inlet port; a main valve connected between the outlet port and the first cross-flow port; a bypass valve connecting the inlet port to the second cross-flow port and the recharge pump inlet; and a purge valve connecting the first cross-flow port and the main valve to a purge port.

An example water purification system for purifying high concentration feed solutions includes a high rejection forward osmosis module, one or more low rejection modules, and a high rejection reverse osmosis module. The low rejection modules may have different rejection levels. The system may be pressurized by one or more pumps. One or more of the low rejection modules may include one or more nanofiltration (NF) membranes. The draw solution may comprise a monovalent salt, a multivalent salt, or a combination of both.

Methods and systems for desalinating feedwater are disclosed. The system includes at least one feedwater source, a reverse osmosis module, an input feedwater stream fed to the reverse osmosis module, and a control module. The feedwater stream comprises water from at least one feedwater source, e.g., from two or more feedwater sources of different salinities. The control module analyzes the level of energy available to the system, and increases the salinity of the input feedwater stream proportional to an increase in available energy. Feedwater stream salinity can be adjusted to reach water demand targets and fully utilize variable power inputs from renewable sources.

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 contaminates 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 is a reverse osmosis treatment system capable of simultaneously and efficiently recovering energy generated both at brine and permeate sides. The system comprises a branched portion configured to divide second to-be-treated water into third and fourth to-be-treated water; a high-pressure pump configured to pressurize the third to-be-treated water thereby to feed fifth to-be-treated water having a higher pressure than the to-be-treated water before divided; a displacement type of first energy recovery device configured to exchange pressures between the fourth to-be-treated water and brine thus separated by a reverse osmosis treatment device, thereby to produce sixth to-be-treated water having a higher pressure than the fourth one; and a second energy recovery device configured to raise a pressure of the third to-be-treated water located at a downstream side of the branched portion with a pressure of first permeate thus separated by the reverse osmosis treatment device.

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.

One or more novel processes for producing hydrogen, oxygen, and in some cases, distilled and cleaned water from a contaminated effluent, are disclosed. In one example of utilizing this novel process, the water from contaminated effluent is transferred into a draw solution using an entrochemical system through a vapor-mediated forward osmosis process. The process is enabled by the generation of a wet vacuum in one or more entrochemical cells incorporated into the entrochemical system. This process generates a diluted draw solution that can be utilized as an abundant water feedstock in an electrolyzer for electrolysis, which in turn generates hydrogen and oxygen. In some embodiments, an entrochemical distiller may also be utilized to distill a portion of the contaminated effluent for clean water as a result of thermal transfers during the vapor-mediated forward osmosis process. mediated forward osmosis process.

Provided is a seawater desalination system including reverse osmosis membrane modules each including: a reverse osmosis membrane; and a pressure vessel installing the reverse osmosis membrane, and configured to obtain permeated water and concentrated water using the reverse osmosis membranes housed in the reverse osmosis membrane modules by supplying seawater to the reverse osmosis membrane modules. The seawater desalination system includes a module group including the reverse osmosis membrane modules connected together in parallel. The seawater is supplied to each of the reverse osmosis membrane modules by being supplied to the module group through first and second seawater supply routes. The first and second seawater supply routes are each provided with a liquid transport pump configured to supply the seawater flowing through the seawater supply route to the module group.

A method for treating water high in sulfate includes passing the water at a temperature of 10 C. to 45 C. through a nanofiltration membrane module and a reverse osmosis membrane module in series such that the retentate stream from the nanofiltration membrane module is fed to the reverse osmosis membrane module. A first permeate stream from the nanofiltration membrane module has at least 90% lower sulfate content than the feed stream. A second permeate stream from the reverse osmosis membrane module has at least 95% lower sulfate content than the retentate stream from the nanofiltration membrane module. The first and second permeate streams are combined to form a treated stream containing less than 40 ppm sulfate. A system including the nanofiltration and reverse osmosis membrane modules in series is also disclosed.

Provided is a reverse osmosis treatment system capable of simultaneously and efficiently recovering energy generated both at brine and permeate sides. The system comprises a branched portion configured to divide second to-be-treated water into third and fourth to-be-treated water; a high-pressure pump configured to pressurize the third to-be-treated water thereby to feed fifth to-be-treated water having a higher pressure than the to-be-treated water before divided; a displacement type of first energy recovery device configured to exchange pressures between the fourth to-be-treated water and brine thus separated by a reverse osmosis treatment device, thereby to produce sixth to-be-treated water having a higher pressure than the fourth one; and a second energy recovery device configured to raise a pressure of the third to-be-treated water located at a downstream side of the branched portion with a pressure of first permeate thus separated by the reverse osmosis treatment device.