According to various aspects and embodiments, a system and method for polishing ultrapure water (UPW) is disclosed. The water polishing system includes a source of ultrapure water (UPW), an ultrafiltration (UF) module having an inlet and a permeate outlet, a recirculation conduit communicating the permeate outlet with the inlet and forming a recirculation loop, a recirculation pump disposed along the recirculation conduit upstream from the inlet of the UF module and fluidly coupled to the source of UPW, a supply conduit fluidly coupled to the recirculating conduit and a demand source, the supply conduit positioned downstream from the permeate outlet, and a pressure control valve disposed along the recirculation conduit downstream from the supply conduit and configured to maintain pressure of permeate at a predetermined value.

Processes and systems for filtering a liquid sample are provided. Batches of a liquid sample can be routed to two or more cycling tanks (e.g., first and second cycling tanks). Upon filling a first cycling tank, a first batch of the liquid sample can be routed to a filtration assembly by a continuous diafiltration process that includes routing produced retentate back to the first cycling tank or to a collection vessel. Upon filling a second cycling tank, a second batch of the liquid sample is routed to the filtration assembly by a continuous diafiltration process that includes routing produced retentate back to the second cycling tank or to the collection vessel. The filling and continuous diafiltration of batches of the liquid sample continues to alternate between the two or more cycling tanks until a total product volume is processed.

A filter module (10) has a housing (12) which is subdivided by a membrane filter (14) into an inlet chamber (16), which is connected to an inlet connecting piece (22) arranged rigidly on the housing (12), and an outlet chamber (18), which has a filtrate outlet (20). The inlet connecting piece has two connectors, specifically a first connector (26) and a second connector (28), which connect selectively and fluidically to the inlet chamber with a 3-way valve (24) integrated into the inlet connecting piece. The valve has a first entry, which is connected to the first connector, a second entry, which is connected to the second connector, and an exit, which is connected to the inlet chamber. The first connector is configured as an adapter for outwardly sealed coupling of a culture medium bottle (30), which coupling permits a gravity-driven exchange of liquid with the first entry of the valve.

A chemical liquid purification apparatus includes a tank body, a return tube, a liquid sending pump, a filtration device and a piping. The tank body has a liquid passage port and a circulation port communicated to a storage space inside the tank body. The return tube has one end connected to the circulation port and another end extending to the storage space. The liquid sending pump and the filtration device are located outside the tank body in between the liquid passage port and the circulation port. The piping is connecting the liquid sending pump and the filtration device to the liquid passage port and the circulation port.

A method of operating a dual reverse osmosis/pressure retarded osmosis plant, including when electricity costs less than a first predetermined price, moderate salinity water is pumped into the first portion of a pressure vessel having first and second portions separated by a water permeable/salt impermeable osmotic membrane to yield desalinated permeate in the second portion and brine in the first portion. Further, when electricity costs greater than the first predetermined price, low salinity water is pumped into the second portion and brine is pumped into the first portion to yield pressurized moderate salinity water in the second portion which is run through an energy recovery device to generate electricity. The salinity of the low salinity water is lower than the salinity of the moderate salinity water, and the salinity of the moderate salinity water is lower than the salinity of the brine.

A fluid separation apparatus comprising a fluid separation membrane is provided. The fluid separation apparatus comprises a fluid separation membrane extending in one direction and having a cross-section with a closed curve shape, wherein the fluid separation membrane has a thickness of 0.1 mm to 2 mm, and an outer diameter of 60 mm to 360 mm when the cross-section is adjusted to be circular.

An apparatus for filtering and mineralizing a fluid. The apparatus includes an amount of contaminated fluid located in a reservoir and a cartridge that is located downstream from the reservoir and in fluid communication with it. A filter is in fluid communication with the reservoir and the cartridge. The contaminated fluid is pumped along a pathway from the reservoir to the cartridge so that the contaminated fluid moves through the filter to generate filtered fluid in the cartridge. A pre-determined amount of an additive is associated with the cartridge for adding to the filtered fluid to generate a final fluid with the amount of the additive material.

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

An automated modular filtration system, particularly for low volume tangential flow filtration processes, comprises a plurality of filtration modules formed as separate assemblies and at least one control unit for jointly controlling filtration processes of individual filtration units. Each filtration module contains at least one individual filtration unit for executing a filtration process independent of the other filtration units, first input ports for receiving a first type of fluids, second input ports for receiving a second type of fluids, and exit ports for outputting unused system fluids. First type fluids are process fluids are specific to the filtration processes executed in individual filtration units. Second type fluids are system fluids not specific to filtration processes executed in the individual filtration units. The second input and exit ports establish inter-module connections so system fluids can be forwarded from one filtration module to an adjacent filtration module of the filtration system.

A process for purifying a urea-containing aqueous stream, such as the aqueous stream from the recovery section of a urea plant, comprising a step of removing biuret from the urea-containing stream by reverse osmosis in one or more reverse osmosis stages.