Membranes and filtration modules for producing a concentrated feed stream and a diluted feed stream during operation in a water purification or wastewater treatment system. Filtration modules are provided that include a semipermeable membrane having a first side and a second side, the first side configured to receive a first feed solution stream from a first feed solution source and the second side configured to receive a second feed solution stream from a second feed solution source. The semipermeable membrane may be configured to operate at a hydrostatic pressure on the second side of the membrane from about 1% to about 40% of the hydrostatic pressure on the first side of the membrane, and may in some cases exhibit a salt rejection of from about 60 percent to about 90 percent during operation.

The present invention provides compact spiral-wound filter elements having cassette-like performance. The invention further provides filtration systems (e.g., TFF systems) and processes (e.g., SPTFF processes) employing compact spiral-wound filter elements having cassette-like performance.

Spacers for filtration membranes that are formed from perforated films. The spacer include unperforated regions, which can serve as integrated lamination strips, advantageously omitting the need for separate lamination steps required with woven and nonwoven spacer fabrics while also providing a spacer with a uniform thickness.

According to the present invention, it is possible to obtain a separation membrane element which has an element configuration having high fresh water production performance and high removal performance, has an improved membrane surface linear velocity whereby fouling due to hardly-soluble salts (scales) or organic matters is less likely to occur on the membrane surface particularly in high recovery ratio operation, and is excellent in fresh water production performance and removal performance over a long period of time.

The present invention provides compact spiral-wound filter elements having cassette-like performance. The invention further provides filtration systems (e.g., TFF systems) and processes (e.g., SPTFF processes) employing compact spiral-wound filter elements having cassette-like performance.

An osmosis element comprising a central permeate tube and a membrane element, the membrane having a first part and a second part, the first part having a top edge for location adjacent the central tube, the second part being disposed at the opposite edge, the first part comprising a material to allow water to flow therethrough, the second part comprising at least two adjacent permeate spacers extending from the first part to allow water to flow therethrough, the permeate spacers having a semi-permeable membrane attached to opposed faces of the two adjacent permeate spacers, the first part comprising a barrier extending from the vicinity of the top edge, the central tube comprising an external wall and a longitudinally extending internal separator defining a first channel and a second channel each extending longitudinally of the central permeate tube, at least one first aperture extending from the first channel though the external wall and at least one second aperture extending from the second channel through the external wall.

Provided is a spiral membrane element that has a restricted outer diameter and is capable of being decreased in operation energy therefor. The element is a spiral membrane element including plural membrane leaves in each of which a permeation-side flow-channel member is interposed between opposed separation membranes; a supply-side flow-channel member interposed between any two of the membrane leaves; a perforated central pipe on which the membrane leaves and the supply-side flow-channel member are wound; and a sealing part that prevents a supply-side flow-channel member from being mixed with a permeation-side flow-channel member. This element has an efficiency index E of 0.005 to 0.10, the index being calculated in accordance with an expression described below, and the thickness of the supply-side flow-channel member is from 10 to 110 mil. Efficiency index: E=0.0024X0.2373+(Y/(D.sup.2L)) wherein X is a thickness [mil] of the supply-side flow-channel member, Y is an effective membrane area [ft.sup.2] of the separation membranes, D is an outer diameter [inch] of the membrane element, and L is a length [inch] of the membrane element.

The present invention provides compact spiral-wound filter elements having cassette-like performance. The invention further provides filtration systems (e.g., TFF systems) and processes (e.g., SPTFF processes) employing compact spiral-wound filter elements having cassette-like performance.

A component for a spiral wound membrane, suitably for water filtration. The component includes an integrally formed non-uniform lattice structure. The lattice structure includes a first and second repeating unit cell, wherein the first and second unit cell are different.

This invention relates to a multi-element membrane separator and separation method based on spiral-wound membrane elements. It includes a membrane housing, spiral-wound membrane elements, and baffles on both sides of the membrane housing, designed to secure the spiral-wound membrane elements. The permeate tubes of the spiral-wound membrane elements are connected to the openings in the perforated plates. Sealing rings are respectively provided at the connections of the permeate tubes and the perforated plate openings. This multi-element membrane separator enables a more compact arrangement of membrane elements, reducing the footprint of the membrane separation device. It also reduces the use of materials such as membrane housing, pipelines, and connecting fittings, thereby lowering equipment costs and the difficulty of membrane device assembly.