A membrane treatment apparatus (1) comprising: a plurality of flat membrane elements (2) which are immersed in a liquid to be treated, disposed side by side in the first direction so that membrane surfaces face each other; a supporting member (8) for holding the flat membrane element (2) provided at an end part of the flat membrane element on a first side in the second direction; and an aeration means (10) provided below the flat membrane element (2); wherein a lower edge of the flat membrane element (2) is formed to extend upward from the first side to a second side in the second direction, or to extend upward and horizontally from the first side to the second side in the second direction.

A method of operating an immersed membrane filtration system includes a step of providing a liquid flow, for example a recirculation flow, past the surface of the membranes to clean, or help clean, the membrane surface. Since immersed outside-in membranes are effectively filtering out clean water from the effluent, they are also dewatering the effluent. To avoid solids concentration, most immersed membrane systems require that a certain amount of effluent liquid is recirculated back to an area upstream of the membranes. This is called a recirculation flow in general and is, for example, associated with the flow of return activated sludge (RAS) in a membrane bioreactor (MBR). In systems and methods described herein, we control a recirculating flow to have enough energy to scour the surface of the membranes, thus combining its use of providing liquid to the membranes and scouring their surfaces.

In an immersed membrane system, the influent flows into an open membrane tank. The membrane tank can have multiple horizontally spaced immersed membrane units. The immersed membrane units may have flat sheet membrane elements within a membrane case. One or more ducts are provided in the tank for directing the flow of influent to the immersed membrane units. In some examples, the influent is divided into sub-streams that are fed through baffles to a corresponding immersed membrane unit, optionally in generally equal amounts, optionally in a single pass flow pattern. In a process of operating a membrane tank, the influent flow is directed across the bottom of the membrane tank and divided into multiple portions. Each of the multiple portions is fed directly to the bottom of a corresponding immersed membrane unit located in the tank. The influent may be mixed liquor in a membrane bioreactor (MBR).

A membrane element includes a filtration membrane and a flowpath member joined thereto. The flowpath member is made of yarn arranged into a three-dimensional structure, and includes inner spaces through which a permeated liquid permeated through the filtration membrane flows, and an outer bonding surface joined to the filtration membrane. At least part of the yarn forming the outer bonding surface is a low-melting point yarn having a softening point lower than that of a material forming the filtration membrane, or the yarn forming the outer bonding surface is formed by twisting a plurality of constituent yarns, and at least one of the constituent yarns is a low-melting point yarn having a softening point lower than that of the material forming the filtration membrane.

An immersed membranes uses aeration (air bubbles rising past the membranes) as a means to scour the membrane surface and keep it clean from solids, or foulants, allowing for continuous and effective operation. In a module of flat sheet membranes, fine bubble aeration is used to create and maintain space between the membrane sheets. The bubbles inhibit the sheets from touching and clogging together, thus reducing their surface area and their productivity. The aeration may be used for scouring, to supply oxygen to biomass and as a spacer to maintain the working surface area of immersed flat sheet membranes. The face-to-face spacing between the membrane sheets may be 4 mm or less. The bubbles may be less than twice the face-to-face spacing between the membrane sheets.

A method of operating an immersed microporous membrane module includes a step of monitoring membrane performance to sense the onset of sludging in the module. Differences in permeability between permeation in backwashes, or trends in permeability during backwashing and permeability during permeation, or both, are monitored. Solid deposits formed during the onset of sludging may be removed with an in situ de-sludging process. For example, the deposits may be removed by stopping permeation while aerating the module, optionally at an increased rate. At other times, the module is optionally aerated while permeate is withdrawn at an aeration rate correlated to flux. The method may be used in particular with a membrane module having parallel textured flat sheet membranes suspended between a pair of vertically oriented headers. An aerator may be made from an open bottomed channel having an array of holes rising and concentrated towards the center of the channel.

Stack assembly comprising a hollow external housing having a central axis, the external housing extending from a first end to a second end and enclosing a housing space, and a membrane stack comprising a plurality of membranes, wherein the membrane slack is positionable inside the external housing and a number of side plates extending substantially parallel to the central axis, wherein each side plate of the number of side plates is associated with a side of the membrane stack and extending along the associated side and a number of sealing connectors that extend substantially parallel to the central axis and adjacent with an inner surface of the external housing, wherein each sealing connector of the number of sealing connectors is configured to connect two side plates to each other, wherein the sealing connectors and the side plates cooperate to form an enclosing structure, and wherein, in use of the stack assembly, the enclosing structure encloses the membrane stack. The invention also relates to a method for assembling a stack assembly and a method for generating energy or performing an electrodialysis process.

A disc tube reverse osmosis module is provided. In various embodiments, deflector disc assemblies and associated membranes are sequentially alternately disposed from top to bottom. The upper flange is in sealing connection with the central pull rod, the upper lock nut is in threaded connection with an upper end of the central pull rod and located above the upper flange, the yielding water collecting pipe sleeves the central pull rod and is in sealing connection with a lower side of the lower flange, the lower lock nut is in threaded connection with a lower end of the central pull rod, an end of the yielding water receiving pipe is fixedly connected to the yielding water collecting pipe, an inner surface of the shell is respectively in sealing connection with the upper flange and the lower flange, and the water inlet receiving pipe and the concentrated liquid receiving pipe are fixed to the lower flange.

The invention relates to an electrodialysis device for the desalination of water for oil and gas applications comprising: a membrane stack comprising alternating cation- and anion-exchange membranes (2.1, 2.3) and; a plurality of spacers (2.2, 2.4), each spacer being arranged between two successive membranes; wherein at least one of the spacers (2.2, 2.4) comprises a recessed area (3.2) and a non-recessed area (3.3), the non-recessed area (3.3) surrounding the recessed area (3.2), and wherein: the spacer (2.2, 2.4) comprises a central opening (3.1) within the recessed area (3.2); the spacer (2.2, 2.4) is provided with at least four orifices (3.4, 3.5) within the non-recessed area (3.3); the spacer (2.2, 2.4) is provided with respective channels (3.6) which connect at least two of the orifices (3.4) with the central opening (3.1); and one cation-exchange or anion-exchange membrane (2.1, 2.3) is accommodated in the recessed area (3.2). The invention also relates to a water desalination process using the electrodialysis device mentioned above, a process for extracting hydrocarbons from a subterranean formation, as well as a process for the desalination of water performed at a temperature from 35 to 80 C.

There is provided a film separation device 1 equipped with a treatment tank 2 receiving a liquid to be treated, a film unit 3 to be immersed in the liquid to be treated, and a guide mechanism 4. The guide mechanism 4 is composed of holding sections 14 and a guide section 15. The holding sections 14 are provided on a side section of a film cassette 5 constituting the film unit 3, and the guide section 15 is fixed to the treatment tank 2. The guide section 15 has a tank-wall fixed section 15a, an upper extension section 15b, a held section 15c, a lower extension section 15d, and a tank-bottom fixed section 15e. When fixing the film unit 3 to the treatment tank 2, the holding sections 14 are fitted to the held section 15c, thereby guiding the film unit 3 to a predetermined position in the treatment tank 2.