A high recovery variable volume reverse osmosis system where the volume of concentrate cycled through the RO system is reduced in response to recovery levels increasing. By reducing the volume of concentrate cycled through the RO system, this reduces the cycle time of highly saturated concentrate passing through the RO system. Reducing the cycle time of concentrate passing through the RO system tends to minimize or reduce membrane scaling.

A high recovery variable volume reverse osmosis system where the volume of concentrate cycled through the RO system is reduced in response to recovery levels increasing. By reducing the volume of concentrate cycled through the RO system, this reduces the cycle time of highly saturated concentrate passing through the RO system. Reducing the cycle time of concentrate passing through the RO system tends to minimize or reduce membrane scaling.

An embodiment of this disclosure provides a liquid treatment device, including: a housing 10 having a housing body 16 and a cover body 11, wherein the housing body 16 is open at one end in a length direction and is close at the other end, the cover body 11 is matched with the one end of the housing body 16 for sealing the one end, and the cover body 11 is provided with an inlet 13 for a liquid to flow into the cover body 11; a reverse osmosis membrane unit 20 located in an accommodation space enclosed by the housing body 16 and the cover body 11, the reverse osmosis membrane unit 20 including a reverse osmosis membrane 24 for performing reverse osmosis treatment on the liquid, a collector tube 27 collects a purified liquid obtained by the reverse osmosis treatment, and a support rod 22 supporting the reverse osmosis membrane 24, wherein the reverse osmosis membrane 24 includes a liquid inlet 21 at one end in the length direction; and a filter 30 arranged in the cover body 11 and located between the liquid inlet 21 and the inlet 13 and is used to filter the liquid entering the cover body 11 via the inlet 13, the filtered liquid entering the reverse osmosis membrane 24 via the liquid inlet. According to this disclosure, by providing the filter in the space between the cover body of the liquid treatment device and the support rod, the liquid entering the reverse osmosis membrane may be preprocessed, spaces may be saved, installation is convenient, and cost is relatively low.

An exchanger includes a seal; a first channel with an inlet and an outlet; a second channel alongside the first channel and isolated from the first channel by the seal, the second channel including an inlet and an outlet; and a transfer turbine including a first portion with one or more blades located within the first channel, a second portion with one or more blades located within the second channel, and a shaft connecting the first portion and the second portion such that rotation of the first portion is synchronized with rotation of the second portion, the shaft extending through the seal. Related apparatus, systems, techniques, and articles are also described.

An exchanger includes a seal; a first channel with an inlet and an outlet; a second channel alongside the first channel and isolated from the first channel by the seal, the second channel including an inlet and an outlet; and a transfer turbine including a first portion with one or more blades located within the first channel, a second portion with one or more blades located within the second channel, and a shaft connecting the first portion and the second portion such that rotation of the first portion is synchronized with rotation of the second portion, the shaft extending through the seal. Related apparatus, systems, techniques, and articles are also described.

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.

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.

A membrane distillation module includes a housing having a hot inlet for receiving a hot feed and a hot outlet for expelling the hot feed; a porous membrane located inside the housing and having an outside surface that defines an enclosure, the outside surface being configured to contact the hot feed, wherein the porous membrane is configured to prevent the hot feed from passing from outside the porous membrane to an inside of the enclosure; and a non-porous conduit located inside the enclosure, the non-porous conduit having an inlet for receiving a cold feed and an outlet for expelling the cold feed.

A wave-actuated system for desalination of water by reverse osmosis (RO) having a wave energy converter (WEC) subsystem and a RO desalination subsystem is disclosed. The WEC subsystem has a float, a reaction member, and a hydraulic cylinder connected between the float and the reaction member and defining first and second variable volume chambers The RO desalination subsystem has a RO cell containing a RO membrane and a flow smoothing device (FSD). During a first stroke of the WEC subsystem: the float moves in a first direction; and seawater is supplied from the first variable volume chamber to the RO cell and to the FSD. During a second stroke of the WEC subsystem: the float moves in a second direction; seawater is supplied from a seawater intake to the first variable volume chamber; and seawater is supplied from the FSD to the RO cell.

A method for reusing wastewater by using reverse osmosis, according to the present invention, provides a method for preparing pure water through a primary reverse osmosis step, a secondary reverse osmosis step, a foam generation step, and a reverse osmosis membrane washing step. The present invention prepares pure water through several reverse osmosis steps, thereby enabling prepared pure water to be immediately used as industrial water, and washes a reverse osmosis membrane with foam, thereby improving washing efficiency and saving on maintenance costs of a wastewater reuse apparatus.