An apparatus has a plurality of gas transfer membranes. The apparatus floats in water with the membranes submerged in the water. To treat the water, a gas is supplied to the membranes and is transferred to a biofilm supported on the membranes or to the water. Gas is also used to supply mixing or membrane scouring bubbles to the water. The mixing or scouring bubbles can be provided by a cyclic aeration or other gas supply system, which optionally provides gas at a variable pressure to the membranes in parallel or series with an aerator. Condensates can be removed from the membranes, and exhaust gasses from the membranes can be monitored, optionally through one or more dedicated pipes.

A transverse-mounted membrane filtration apparatus includes an air diffuser device including a shelf-shaped member and a gas-feeding unit, the shelf-shaped member including a plurality of shelf boards being arranged in a flow path segment at an immediate upstream of an end surface of a membrane element with a predetermined distance from the end surface of the membrane element and covering an entire flow path of the membrane element along a vertical direction, the gas-feeding unit feeding a gas to the raw water for washing the membrane element through a gas-feeding port provided at a bottom portion of a flow path of the shelf-shaped member. Herein a shelf board at a lowermost position of the shelf-shaped member is inclined toward a side of the end surface of the membrane element in a vertically upper direction.

In a submerged membrane bioreactor (MBR or SMU), diffusers are used to eject air bubbles, primarily to facilitate the movement of mixed liquor past the membrane surfaces, cleaning and scouring the surfaces of the membranes with the mechanical energy of the combined air/liquid/solids movement. Oxygen transfer from the bubbles into the mixed liquor is often a secondary goal, for supplying oxygen to biological processes. The invention involves the use of a specific bubble diffuser, oriented at a selected upward angle, to enable a single style diffuser to accomplish simultaneous generation of mid-size and fine bubble aeration, with adjustment of the tilt angle varying the percentages of mid-size and fine bubble aeration. The angle selection, along with the number of diffusers and air volume selected, allows achievement of target liquid movement through the MBR.

A membrane filter configured to filter a liquid, the membrane filter including a base element including at least one membrane carrier that is externally flowable by the liquid and a gas; hollow fiber membranes respectively including lumen and attached at a top of the at least one membrane carrier wherein a liquid permeate is filterable from the liquid into the lumen; a one piece extruded circumferentially closed pipe that envelops the hollow fiber membranes; a gas inlet configured to let gas into a bottom of the membrane filter; at least one permeate collection cavity included in the base element and connected with the lumen and configured to collect the liquid permeate from the hollow fiber membranes; a permeate outlet included in the base element and configured to drain the liquid permeate from the at least one permeate collection cavity laterally from the base element.

A method for cleaning a cross-flow filter (20), comprising the steps of: A) providing a cross-flow filter (20), wherein the cross-flow filter (20) comprises a filter membrane (21) and is configured to remove a liquid permeate stream and the filter membrane (21) comprises a first side facing the permeate stream and a second side opposite the first side, the second side facing the feed stream, and wherein at least some of the deposits (1010) to be removed are located on the second side of the filter membrane (21); B) applying a back-flushing liquid stream through the filter membrane (21). Prior to applying the back-flushing liquid stream in Step B), permeate located on the first side of the filter membrane (21) is at least partially displaced from the first side of the filter membrane (21) by a gas, wherein the gas that is in contact with the back-flushing liquid stream has a pressure of >1 bar at least during Step B). The applying of the back-flushing liquid stream in Step B) occurs in such a way that the pressure pulses.

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.

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.

An energy-saving filtering system and a hollow fiber membrane module for the same are disclosed. According to the filtering system of the present invention, pretreated feed water flows into the case of the hollow fiber membrane module by gravity, and the filtrate passing through the hollow fiber membrane is discharged from the hollow fiber membrane module by gravity.

An enclosure assembly configured to receive a plurality of fiber membranes configured to filter fluid may include an elongated tubular member including an elongated wall extending between first and second ends, and a removable hatch coupled to opposing side edges of the elongated wall, thereby forming a hollow enclosure having an interior. The interior of the elongated tubular member may be configured to receive a plurality of fiber membranes configured to filter fluid.

A method of sewage treatment includes: immersing a separation membrane module into sewage, wherein the separation membrane module has a plurality of separation membrane elements, each having a supporting plate, a separation membrane and a filtered water outlet; separating water into filtered water and suspended solids by having the water permeated through the separation membrane; and having the filtered water flow toward the exterior from the filtered water outlet;
wherein the separation membrane has a nonwoven fabric and a porous resin layer on at least one surface of the nonwoven fabric; and
a part of the resin permeates into the nonwoven fabric to form a composite layer with the nonwoven fabric.