The hollow fiber membrane module contains a hollow fiber membrane bundle having bundled hollow fiber membranes, a housing with an internal space formed in which the hollow fiber membrane bundle is housed and a gas supply portion which disperses cleaning gas for the hollow fiber membrane in the internal space. The internal space has an upper space in which an upper-side part of the hollow fiber membrane is positioned and a lower space in which a lower-side part of the hollow fiber membrane is positioned. The gas supply portion is provided with pipe vent holes which disperse gas in the housing at a position in the upper space and diffusing vent holes which disperse gas in the housing at a position below the lower space.

The present disclosure is directed to filtering technologies that combine elements of continuous and batch NF/RO based on the constraints of the end-user facility to achieve a target balance between, for instance, recovery and power consumption, and to reduce long term operating cost of a plant. A method for extending batch operation into a second induction period with antiscalant injection is also disclosed herein, with the second induction period allowing for yet higher water recovery.

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.

A method includes measuring, by a flow sensor (70), a flow rate of a permeate fluid (48) flowing through a filter (20) of a membrane filtration system (12). Further, the method includes receiving, by a control unit (86), the measured flow rate of the permeate fluid (48) and determining, by the control unit (86), a first flux rate of the filter (20) based on the measured flow rate of the permeate fluid (48). Furthermore, the method includes comparing, by the control unit (86), the determined first flux rate with a first predetermined flux rate. Additionally, the method includes operating the membrane filtration system (12), by the control unit (86), in a normal mode or a flux tolerant mode based on the comparison of the determined first flux rate with the first predetermined flux rate. The flux tolerant mode of the membrane filtration system (12) is further based on a determined normalized water permeability value of the filter (20).

A membrane separation process is described. The process comprises pumping of a fluid stream through a membrane module to produce a permeate during a plurality of membrane operating cycles. Each membrane operating cycle comprises a filtration cycle and a relaxation cycle. Concentration polarisation is controlled during the process by controlling duration of filtration cycles and relaxation cycles to relatively short duration to maintain the degree of concentration polarisation below a target.

The present disclosure is directed to filtering technologies that combine elements of continuous and batch NF/RO based on the constraints of the end-user facility to achieve a target balance between, for instance, recovery and power consumption, and to reduce long term operating cost of a plant. A method for extending batch operation into a second induction period with antiscalant injection is also disclosed herein, with the second induction period allowing for yet higher water recovery.

The present disclosure is directed to filtering technologies that combine elements of continuous and batch NF/RO based on the constraints of the end-user facility to achieve a target balance between, for instance, recovery and power consumption, and to reduce long term operating cost of a plant. A method for extending batch operation into a second induction period with antiscalant injection is also disclosed herein, with the second induction period allowing for yet higher water recovery.

Provided herein is a universally applicable biofouling mitigation technology using acoustically excited encapsulated microbubbles that disrupt biofilm or biofilm formation. For example, a method of reducing biofilm formation or removing biofilm in a membrane filtration system is provided in which a feed solution comprising encapsulated microbubbles is provided to the membrane under conditions that allow the encapsulated microbubbles to embed in a biofilm. Sonication of the embedded, encapsulated microbubbles disrupts the biofilm. Thus, provided herein is a membrane filtration system for performing the methods and encapsulated microbubbles specifically selected for binding to extracellular polymeric substances (EFS) in a biofilm.

A water desalination system including at least one reverse osmosis desalination unit, including at least one reverse osmosis membrane and having a saline water inlet at a feed side of the at least one reverse osmosis membrane and a permeate outlet at a permeate side of the at least one reverse osmosis membrane, and an intermittent cleaning control subsystem operative to provide intermittent cleaning of the at least one reverse osmosis membrane by at least one of narrowing or closing the permeate outlet, thereby causing an increase of pressure of the permeate at the permeate side of the at least one reverse osmosis and reducing the feed pressure, without significantly increasing the permeate pressure, thereby causing permeate to flow from the permeate side to the feed side of a membrane and flushing foulants to a location outside of the desalination unit.

A filtration filter is suitable for performing cross-flow filtration by using a metallic porous membrane. A metallic porous membrane has a membrane portion for filtering filtration objects contained in a fluid and a held portion provided at its outer periphery. A first frame member and a second frame member hold the held portion of the metallic porous membrane there between. The held portion has a bent portion bent to a second principal surface side opposing a first principal surface of the membrane portion. The first frame member is in contact with the held portion at the first principal surface side of the metallic porous membrane. The second frame member is disposed at an inner side portion of the first frame member and is in contact with the held portion at the second principal surface side of the metallic porous membrane.