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.

The invention discloses an automatic off-line gas-water combined-washing membrane bioreactor, comprising a PLC automation control cabinet, a MBR reactor, a MBR membrane assembly, a rotating hood, an annular guide rail, a lifting device, a washing pipe network, an external interface, a gas washing pipe, a water washing pipe, a gas pump and a water pump, wherein the gas pump, the water pump and the three-way change valve are all connected with the PLC automation control cabinet, the washing pipe network is provided with several nozzles. The present invention adopts a full PLC automation control system, the PLC automation control cabinet controls a pressure washing pump (gas pump and water pump), and gas or water is injected into the washing pipe network by flexibly adjusting the three-way change valve, so that the operation is simple, the cleaning is complete, and the manual operation load is reduced.

The present disclosure provides a method for preventing membrane fouling in a fluid treatment system having at least one membrane. The method describes hydrodynamically cavitating a fluid flow prior to injecting it into the fluid treatment system and through the at least one membrane, wherein after undergoing hydrodynamic cavitation in the cavitation reactor, solid components in the fluid change their (i) molecular structure, (ii) a charge, or both, such that the components repulse each other and disperse around an edge of the membrane to prevent fouling. A system for preventing membrane fouling in a fluid treatment system having at least one membrane is also provided.

A membrane filter is treated with formulated oxide powder and submerged in a liquid to be treated. Colloids in the liquid to be treated are separated and removed, and a colloid-free gap is maintained between the filtered colloids and the formulated oxide powder on the surface of the membrane by adjusting the flux rate which may typically range from 250-750 litres per m.sup.2 per hour. A low trans-membrane pressure is maintained across the membrane while the colloid-free gap is maintained, and a low turbidity is achieved in the filtered liquid.

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 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. In a first phase of the filter cleaning sequence, a first fluid including a blood-compatible and physiologically safe fluid is transferred back and forth across the insides and/or outsides of the blood filter. After the first phase, a second fluid is formed by mixing the first fluid with air. In a second phase of the filter cleaning sequence, the second fluid is transferred across the insides and/or outsides of the blood filter at least one time.

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

A purge air regulating unit for a drying device for compressed air, the purge air regulating unit being connectable to a housing in which a membrane filter, such as a bundle of hollow fiber membranes, is arranged such that a sub-flow of dried compressed air flowing out of the housing from an outlet channel can be conducted back to the hollow fiber membranes as purge air by the purge air regulating unit. A method for regulating the flow of dried compressed air flowing out of a membrane dryer back into a housing of the membrane dryer, the membrane dryer being equipped with a membrane filter, such as a bundle of hollow fiber membranes, is also provided.

An apparatus for enhanced anti-fouling of a submerged surface includes a bath of a feed liquid that includes water; a fouling structure in contact with the feed liquid; and a gas feed configured to introduce a gas into contact with the fouling structure and the feed liquid to separate the fouling structure from the feed liquid with a gas layer.

A membrane filter for filtering a liquid to be filtered, the membrane filter including at least one membrane carrier to which membranes are fixed, the membranes allowing a liquid permeate to be filtered out of the liquid, and the membrane carrier includes a permeate collecting chamber to which the membranes are connected in an open manner on the permeate side, and also comprises a permeate outlet for the discharge of the permeate out of the permeate collecting chamber; a gas distribution system which is arranged below the at least one membrane carrier and which has at least one downwardly open and upwardly closed tub which has a wall with downwardly open vertical slots for the distribution of a gas into the liquid to be filtered, at least one gas inlet leading into the gas distribution system. The invention also relates to a method for filtering a liquid.