A reverse osmosis desalination system has a combined displacement pump and displacement pressure recovery motor that propagate feed water with a structurally fixed recovery rate and structurally stabilized volume flow through continuously alternating discharging and recirculation intervals. Thereby enabled is an instantaneous discharge of the entire feed water concentrate and unmixed replacement with low salinity source water that intermittingly and effectively flushes the reverse osmosis membranes. This in turn provides for high recirculation peak salinity and recovery rate that are simple and reliably controlled without impairing membrane longevity.

A filtration apparatus for a container, the apparatus includes a connection portion for securing the apparatus to the container; a housing; a hand pump attached to the housing, the hand pump comprising an inlet, an outlet, and a user-operated actuator, the hand pump is configured to pass filtered water through the inlet in a first direction towards the outlet of the hand pump during a first stroke of the user-operated actuator, and in both the first direction and in a second direction opposite to the first direction during a second stroke of the user-operated actuator; and a filter fluidly connected to the inlet of the hand pump, the housing is configured to house the filter and at least part of the hand pump, the housing is configured to pass water, the filter is configured to be a two-way valve for regulating water flow between the housing and the hand pump.

The disclosure provides a bifunctional composite membrane, a preparation method and use thereof, and a method for removing a plasticizer in liquor. The bifunctional composite membrane includes a supporting membrane and a dense layer which covers a surface of the supporting membrane, wherein the supporting membrane includes a filtering membrane and an adsorbent, and the adsorbent is dispersed in a pore structure of the filtering membrane.

A method for desalination is provided. An electric potential difference is applied across a saline solution, where a salinity of the saline solution is in a range of 2.5 to 7.8 parts per thousand. The saline solution is separated, using electrodialysis, into a concentrated saline solution and a first diluate. The concentrated saline solution is transferred to a reverse osmosis chamber. The concentrated saline solution is pumped through a partially permeable membrane, thereby removing salt ions from the concentrated saline solution, and creating a second diluate and a brine solution. A pressure of the solution is then increased, using a pressure exchanger, by transferring water pressure from the brine solution to the concentrated saline solution. The first diluate and the second diluate are combined, where a first recovery ratio of the first diluate is greater than a second recovery ratio of the second diluate.

A method of desalinating water, including the steps of when electricity costs between a first predetermined price and a second predetermined price, fill water is pumped into a reverse osmosis desalination unit to yield desalinated permeate and saltwater having a first salinity, when electricity costs less than the first predetermined price, fill water is pumped into a reverse osmosis desalination unit to yield desalinated permeate and saltwater having a second salinity, and when electricity costs greater than the second predetermined price, pure water is flowed into a reverse osmosis unit to yield pressurized saltwater which is run through a turbine to generate electricity. The first salinity is lower than the second salinity.

A technique for separating components of a microfluid, comprises a self-intersecting micro or nano-fluidic channel defining a cyclic path for circulating the fluid over a receiving surface of a fluid component separating member; and equipment for applying coordinated pressure to the channel at a plurality of pressure control areas along the cyclic path to circulate the fluid over the receiving surface, applying a pressure to encourage a desired transmission through the separating member, and a circulating pressure to remove surface obstructions on the separating member. The equipment preferably defines a peristaltic pump. Turbulent microfluidic flow appears to be produced.

A fluid processing system includes a disposable fluid circuit and reusable hardware configured to accept the disposable fluid circuit. The disposable fluid circuit includes a spinning membrane separator, first and second syringes, and a flow control cassette. The reusable hardware includes a spinning membrane separator drive coupled to the spinning membrane separator, first and second syringe pumps coupled to the first and second syringes respectively, a control cassette interface coupled to the flow control cassette, and at least one controller coupled to the spinning membrane separator drive, the first and second syringe pumps, and the control cassette interface. The controller is configured to selectively operate the drive, the first and second syringe pumps, and the interface to provide a procedure according to a protocol.

The disclosed technology includes a water filtration unit. A disclosed water filtration unit includes a filtration unit housing defining a filtration unit cavity; an inlet coupled to the filtration unit housing; a pump positioned at least partially within the filtration unit cavity and including a pump inlet and pump outlet, the pump inlet coupled to the inlet; a filter housing positioned at least partially within the filtration unit cavity and including a filter inlet and filter outlet, the filter inlet coupled to the pump outlet and filter outlet coupled to a water dispenser; and a power source in communication with the pump to power the pump to push water through the filter housing when the water filtration unit is coupled to a water source.

This specification describes membrane based filtration and softening systems and methods. A system has a microfiltration or ultrafiltration (MF/UF) membrane unit upstream of a nanofiltration or reverse osmosis (NF/RO) membrane unit, optionally with no intermediate tank. In some cases, the system and method may be used with feed water provided at municipal line pressure to the membranes. NF/RO permeate is collected in a tank and then pumped to a header. Treated water may be drawn from the header for use or recycled to the system, for example to backwash or flush one or both of the membrane units. In a combined process, NF/RO permeate flushes the feed side of the NF/RO unit and then backwashes the MF/UF unit. In another process, the MF/UF unit and NF/RO unit are filled with NF/RO permeate before being placed in a standby mode.

The disclosure relates to systems, devices, and methods for flow control in a reverse osmosis filtration system, such as within a medical device. The systems, devices, and methods can respond to changes in permeate flow rate and solute concentration by adjusting feed water and concentrate water rates. Multiple feedback loops adjust parameters to meet water flow rate and purity requirements.