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 diffuser membrane and a method for manufacturing the same are provided. In the method for manufacturing, a first material is heated and extruded to form a base layer and a second material is heated and extruded to form a coating layer. The base layer and coating layer may be extruded substantially simultaneously in a coextrusion process. Accordingly, the coating may be applied to the base layer in a manner that optimizes the bonding between the two layers and provides the ability to control the thickness of the coating layer. Alternatively, the base layer is formed initially and the coating layer is subsequently formed thereover. The first and second materials have differing properties. The first material may comprise polyurethane and the second material may comprise polyurethane and PTFE.

A container system includes a collapsible bag having an interior surface at least partially bounding a chamber, the chamber being adapted to hold a fluid. A sparger is disposed within the chamber of the bag, the sparger bounding a compartment and having an inside edge that encircles an opening passing through the sparger. At least a portion of the sparger is gas permeable. A tubular member is coupled to the sparger and is in communication with the compartment. A shaft passes into the chamber of the bag and through the opening of the sparger. A mixing element is secured to the shaft and is disposed within the chamber of the bag.

A water aeration diffuser has a base with an internal cavity defining an air pocket, and a ceramic plate removably attached to the base. The base is in flow communication with air supply such that air is received in the cavity and then diffused by the ceramic plate to create an aeration column in a body of water. To allow for repair and servicing, the ceramic plate is removably attached to the base by one or more fasteners. The base includes a perimeter lip around its top portion that supports the ceramic plate and maximizes the exposed surface area of the plate. A water and air-tight gasket is provided between the lip and the ceramic plate. An eye-bolt may be provided through the ceramic plate and attached to the base to provide an attachment point for a ballast or other means used to position the diffuser.

A container system includes a bag comprised of one or more sheets of flexible polymeric material, the bag having an interior surface at least partially bounding a chamber, the chamber being adapted to hold a fluid. A flexible sparging sheet is secured to the interior surface of the bag so that a compartment is formed between the interior surface of the bag and the sparging sheet, at least a portion of the sparging sheet allowing gas to pass therethrough. A tubular port or tube is secured to the bag so that a passage bounded by the tubular port or tube communicates with the compartment. A mixing element is disposed within the chamber of the bag, the mixing element being spaced apart from the flexible sparging sheet.

An air diffuser includes: a bottom panel provided in a horizontal direction in a tank in which water is filled; an air diffusion body installed to cover the bottom panel from above; and air diffusion holes arranged to penetrate through the air diffusion body, gas fed to a gap between the bottom panel and the air diffusion body is discharged into water through the air diffusion holes, and an air diffusion region of the air diffusion body where the air diffusion holes are arranged has a width equal to or larger than 10 mm and smaller than 120 mm. A method of treating water using the air diffuser includes supplying air to the air diffuser at a volume of equal to or smaller than 60 [Nm.sup.3/(m.sup.2.Math.hr)].

A system for mixing and mixing processes and structures are disclosed. In addition a nozzle used for mixing is disclosed.

The device includes a vessel for filling with a mixture of water and a foam-forming component. The vessel comprises a device for injecting air into the foam generation mixture. The device has at least two vessels arranged one above the other in a vertical direction in a leveled form for filling with the mixture and for injecting air into the foam generation mixture. The vessels are open towards an outlet region in such a way. The foam generated in the vessels is merged in the outlet region.

A system may include a nanobubble generator that uses a shearing force applied by a fluid received through a fluid inlet and a negative pressure applied to an outlet by a pump to provide a vacuum-assisted shear flow nanobubble generator system. In some implementations, the system may include a nanobubble generator including a porous component including a chamber coupled to receive a gas and including a surface having a plurality of gas-permeable openings. The nanobubble generator may include an inlet and an outlet on opposing sides of the porous component to direct the fluid across the openings. The system may include a pump to apply a negative pressure to the outlet of the nanobubble generator. The negative fluid pressure and the fluid flow across the openings cooperate to form nanobubbles at low injected gas pressures, increasing the efficiency of production of nanobubble solutions with pressure sensitive gasses, such as ozone.

An elongate diffuser is disclosed comprising a diffuser body and a membrane attached to the diffuser body. The membrane is connected to the diffuser body so that introduction of gas at a working pressure into the diffuser displaces part of the membrane from contact with the diffuser body to provide an elongate sealed compartment between the membrane and a surface of the diffuser body. The compartment has a first lateral side interface region where the membrane contacts the diffuser body, a laterally intermediate region where the membrane is spaced apart from the diffuser body and a second lateral side interface region where the membrane contacts the diffuser body. The diffuser body surface which bounds the compartment comprises a recessed portion which is recessed away from the membrane between the first second lateral side interface regions.