Algae harvesting and cultivating systems and methods for producing high concentrations of algae product with minimal energy. In an embodiment, a dead-end filtration system and method includes at least one tank and a plurality hollow fiber membranes positioned in the at least one tank. An algae medium is pulled through the hollow fiber membranes such that a retentate and a permeate are produced.

A water treatment membrane washing apparatus includes two ozone dissolving tanks for storing filtrate generated by filtering raw water through a water treatment membrane and gas aspirators provided for the respective ozone dissolving tanks, for mixing the filtrate with ozone gas supplied from an ozone supply unit to generate ozone gas containing filtrate, and is configured such that waste ozone gas generated in one of the ozone dissolving tanks is aspirated by the gas aspirator provided for the other ozone dissolving tank. After the filtrate from the raw water is pretreated by being mixed with the waste ozone gas in the aspirator, the pretreated filtrate is mixed with the ozone gas in the other ozone dissolving tank until it reaches a predetermined concentration. The ozone gas containing filtrate is supplied from the secondary side of the water treatment membrane to the primary side thereof to wash the eater treatment membrane.

A method of filtering a fluid with components includes providing an alternating pressure. The alternating pressure yields an oscillating transmembrane pressure through volume and pressure variations within a filtration chamber while sealing the filtration chamber. A separation surface can be housed in the filtration chamber wherein an influent is introduced. Components can be concentrated on the separation surface, effectively removing some or all of them from the fluid. To flush the filtration chamber and separation surface, a backwash fluid and components can be introduced and removed from the filtration chamber. While both the components are being concentrated and backwashed, the system can maintain the oscillating transmembrane pressure and varying volume and pressure relative to the separation surface.

Systems and methods for exchanging buffer solutions are disclosed. In accordance with some embodiments, the methods and systems for buffer exchange may be automated and/or the methods and systems may include mixing during filtering operations.

A corrugated membrane plate and frame module for use in fluid treatment applications is disclosed, where the corrugated design increases production capacity of a module by more than 200% as compared to conventional modules. The increase is achieved by tripling the membrane packing density per module using an optimized corrugated design. The disclosed corrugated membrane plate and frame also reduces the inactive membrane area per module, which is caused by deactivation of membranes edges attached to the plate and frame core in order to prevent leakage.

A renal therapy apparatus includes a blood filter, a blood pump, a treatment fluid pump, and a control unit configured to control at least one of the blood pump or the treatment fluid pump during a filter cleaning sequence. The blood filter includes a plurality of hollow fiber membranes. During the filter cleaning sequence, a fluid mixture is formed by mixing air with a blood-compatible and physiologically safe fluid. Also during the filter cleaning sequence, the fluid mixture is transferred across insides and/or outsides of the plurality of hollow fiber membranes at least one time. The use of the fluid mixture enables the filter cleaning sequence to be performed during the blood treatment.

A process is disclosed for wetting a filter cartridge used to treat a liquid solvent used in semiconductor manufacture. In the process, a filter cartridge having void spaces wherein the void spaces contain residual gas from the manufacturing process used to make the filter cartridge is connected to a source of purging gas. The purging gas is flowed through the filter cartridge to at least partially displace at least a portion of the residual gas from the manufacturing process used to make the filter cartridge. Next, liquid solvent is pumped through the filter cartridge so that the purging gas dissolves into the liquid solvent and to at least partially fill the void spaces to thereby at least partially wet out the filter cartridge with the liquid solvent.

An ultrafiltration/nanofiltration membrane with gas-tunable pore size is provided. This membrane comprises an active layer arranged between two porous support layers, wherein the active layer is formed of randomly arranged cellulose nanocrystals, wherein pores are defined in the active layer by the free spaces existing between the randomly arranged cellulose nanocrystals, and wherein chains of a CO.sub.2-responsive polymer are grafted on the surface of the cellulose nanocrystals. There are also provided methods for filtering a feed using the membrane, for tuning the apparent pore size/MWCO/charge of the membrane, for cleaning the membrane, and for manufacturing the membrane.

A membrane defect inspection method is for a membrane module set including a plurality of membrane modules connected in parallel under a straight pipe portion of gas detection piping extending in a horizontal direction and communicating with primary spaces in the plurality of membrane modules to which raw water is supplied or secondary spaces. The method includes a gas injection process where gas is injected into spaces opposite to the primary spaces or the secondary spaces communicating with the gas detection piping while the gas detection piping is filled with water, and an echo detection process where an ultrasonic sensor is brought into contact with an end portion of the straight pipe portion of the gas detection piping, and a reflected wave of an ultrasonic wave transmitted from the ultrasonic sensor is detected.

Algae harvesting and cultivating systems and methods for producing high concentrations of algae product with minimal energy. In an embodiment, a dead-end filtration system and method includes at least one tank and a plurality hollow fiber membranes positioned in the at least one tank. An algae medium is pulled through the hollow fiber membranes such that a retentate and a permeate are produced.