A gas separation element comprising a membrane sheet and a permeate spacer, wherein the membrane sheet comprises a porous support and a discriminating layer, CHARACTERISED IN THAT: (a) the permeate spacer has an open space volume of at least 0.0004 m.sup.3/m.sup.2; and (b) the membrane sheet has an aspect ratio of at least 1.5.

The co-generation of hydrogen from water produced during pressure driven water desalination/filtration processes, such as reverse osmosis, forward osmosis, pressure retarded osmosis or ultrafiltration, is described herein. A small part of feed, raw saline solution and/or permeate involved in a desalination/filtration processes is subjected to electrolysis thereby splitting the water to produce hydrogen. This is achieved by the provision of novel RO type semi-permeable membranes and UF type membrane that incorporate electrodes within the membrane to allow splitting of the water via electrolysis.

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.

Embodiments of the present invention provide for the deposition of spacing elements for spiral wound elements that prevent nesting of adjacent spacer layers and occlusion of feed space during element rolling.

The invention relates to membranes, membrane modules, and applications therefor. In particular, the invention relates to the construction of membranes and membrane modules for use in osmotically driven membrane processes.

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 discloses membrane modules utilizing innovative geometries of net-type feed spacers for improved performance in separations and spacer-fabrication methods therein. Membrane modules include: a central tube having perforations along its length for collecting a permeate; at least two filtration envelopes, each filtration envelope having two membrane sheets and a porous, fabric-type insert in between the two membrane sheets for facilitating the permeate to flow, wherein each envelope is closed along three edges of the two membrane sheets, and wherein each envelope is configured to allow the permeate to exit from a fourth, open edge attached to the central tube; and a respective feed-spacer sheet in planar contact with an outer membrane surface of a respective filtration envelope; wherein the respective feed-spacer sheet is in the form of net having nodes connected by flexible segments such that the net forms a regular planar net.

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.

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.

According to the present invention, even when a high recovery ratio operation is performed, the influence of concentration of ingredients to be separated in the feed fluid can be reduced, the concentration polarization can be prevented by increasing the turbulence effect on the membrane surface, and the fluid permeation performance and the separation performance of the separation membrane element can be maintained.