Raw liquid is fed along a raw liquid and drain liquid mixing line to a liquid purification device. Drain liquid is fed along a recirculation line to be mixed with raw liquid. After a set period of time, the liquid purification process is interrupted to flush the liquid purification device by a liquid to remove contaminants built up on the inside surface of the liquid purification device. Downstream of the liquid purification device, the liquid is discharged at high speed into a drain. Prior to flushing, the purification process is interrupted at least once for a time sufficient to enable disruption of a polarized layer of contaminants. A mixture of raw liquid and drain liquid is used as the liquid medium for flushing such that less raw liquid is used for flushing and the service life of the water purification device increases.

Systems and methods used to control tangential flow filtration are provided, including control systems and methods for use with connected systems with upstream processing units, such as chromatography processing units, in fluid communication with a tangential flow filtration processing unit. Also included are control systems and methods for performing continuous concentration using single-pass tangential flow filtration with permeate flow control.

A desalination system that is deployable in a body of water having a surface and a seafloor and which includes a vessel structure that is capable of travel in water, a reverse osmosis system disposed within an internal space of the vessel structure and a tank connected to the reverse osmosis system, the tank configured to receive filtered water from the reverse osmosis system. A positioning system is provided for controlling the travel of the vessel structure, and a ballast system is configured to control the buoyancy of the vessel structure. A controller is operably associated with the positioning system and the ballast system to control the position of the vessel below the surface of the body of water.

A water purification system includes a tank which stores permeate during periods of standby during which impurities can migrate across a filtration membrane, resulting in impure water on the downstream side of the membrane. During an initial portion of a water draw immediately following a period of standby, the impure water on the downstream side of the membrane is used as a motive fluid to force the permeate out of the tank for delivery to the faucet. Permeate is provided on a continuous bases directly from the membrane to the faucet after the tank is depleted of permeate. The system includes a control system and a plurality of valves to recycle the impure water used as a motive fluid to the membrane to produce permeate. At the conclusion of a water draw, the tank is filled with permeate and the system enters a period of standby until the next water draw.

A top fill water reservoir system that allows the reservoirs to be filled without waiting for a reverse osmosis (RO) filter to produce enough water to fill the system and avoids the need for a service worker to remove the system from the cabinet, or wait for RO filtration, to fill the reservoirs. The top fill water reservoir system comprises a drinking reservoir adapted to store and dispense drinking water. A supply reservoir in fluid communication with the drinking reservoir and adapted to feed water into the drinking reservoir and receive water from a reverse osmosis (RO) filter. An overflow tube adapted to connect an upper portion of the drinking reservoir to the supply reservoir and feed overflow water from the drinking reservoir to the supply reservoir.

A method for the treatment of water using reverse osmosis (RO) membranes and nano-filtration membranes wherein the permeate of the membranes is fluid connected to a feed water source via a pressurized storage buffer tank as well as to the fluid connection to use, the method comprising the steps of supplying treated water through a sanitary fully pressurized buffer tank, and supplying waste water through a recirc loop which contains recirculated concentrate and storing treated water in the buffer tank with low total dissolved solids of less than 10% of feed water, low pH of less than pH 7, and of low total organic carbon of less than 25% of feed water ensuring sanitary storage. It further includes opening a waste valve in the recirc loop which purges recirculated concentrate in order to rapidly reduce the conductivity of the water in the recirc loop. It further includes the steps of operating the waste valve such that it maintains the conductivity of the recirculated waste water in the recirc loop within a pre selected range of values and opening the waste valve when a measured conductivity setpoint is exceeded, and closing the waste valve when a measured conductivity setpoint is met.

Tangential flow filtration systems utilizing flexible bags for permeate collection are provided.

Disclosed herein is a water purifying system, including: a raw water tank configured to store raw water; a filter unit configured to include a plurality of filtration modules for purifying the raw water and a plurality of valves for feeding or cutting off the raw water; a raw water pump configured to feed the raw water from the raw water tank to the filter unit; and a backwash module configured to feed backwash water to the filter unit, in which some of permeate water permeated by the filter unit is fed to the backwash module to be used as the backwash water and a feed pressure of the backwash water is fed by the raw water pump.

A water treatment apparatus is disclosed. The water treatment apparatus, according to one embodiment of the present invention, may comprise: a filter unit comprising a reverse osmosis filter for supplying purified water filtered from raw water, and residential water which could not be filtered from raw water; a storage unit connected to the filter unit and comprising a storage member in which purified water is stored, then discharged, and a housing within which the storage member is provided, and through which residential water inflows and outflows; and a flow path changing valve connected to the filter unit and the storage unit, and which allows residential water to outflow from the housing as purified water is stored in the storage member, or allows purified water to be discharged from the storage member as residential water inflows into the housing.

Disclosed is a water treatment apparatus which can extract clean water by means of the pressure of raw water. The disclosed water treatment apparatus comprises: a filter part which filters raw water; a storage part which stores clean water filtered by passing through at least a part of the filter part, the storage part having a first chamber and a second chamber of which the volume changes according to a change in the volume of the first chamber; an extraction part which is installed so as to provide the filtered clean water to a user; and an air supply part which is installed on a flow path connected to the storage part in order to supply air to either one of the first chamber or the second chamber of the storage part.