A method for producing a spiral wound separation membrane element includes preparing a composite semipermeable membrane having a skin layer on the surface of a porous support. The method further includes forming on the skin layer a protective layer containing 35 mg/m.sup.2 or more of an anionic polyvinyl alcohol to prepare a protective layer-equipped composite semipermeable membrane, preparing an unwashed spiral wound separation membrane element from the protective layer-equipped composite semipermeable membrane, and passing wash water through the unwashed spiral wound separation membrane element to remove the protective layer on the skin layer.

A process for separating a feed gas comprising polar and non-polar gases into a gas mixture enriched in polar gas(es) and a gas mixture depleted in polar gas(es), the process comprising passing the feed gas through a gas separation unit comprising at least two gas-separation modules in order of increasing selectivity for the polar gas(es), wherein the feed gas entering the gas separation unit comprises more than 35 mol % and up to 90 mol % of polar gas(es).

Disclosed is a central tube set. The central tube set includes: a permeate tube, a peripheral wall of the permeate tube being arranged with a pure water influx hole communicating with an internal channel of the permeate tube; and a plurality of wastewater tubes arranged at intervals. The wastewater tubes are arranged around the permeate tube, a peripheral wall of each wastewater tube is arranged with a wastewater influx hole communicating with an internal channel of each wastewater tube. The plurality of the wastewater tubes and the permeate tube are arranged at intervals, to form a receiving space between each wastewater tube and the permeate tube, for receiving a portion of the reverse osmosis membrane sheet set which is extending into the central tube set. The present application further provides a spiral wound reverse osmosis membrane component and a reverse osmosis water purifier.

Disclosed herein methods for combating biofouling in a liquid, e.g. an aqueous medium by providing a surface coated with at least one laser-induced graphene (LIG) layer in said liquid medium. Particularly disclosed herein method and devices for treating water comprising passing a water stream through a membrane module equipped with at least one spacer coated with at least one layer of LIG, and optionally by applying an electric potential to the at least one LIG layer to achieve a bactericidal effect in the water stream. Specifically, disclosed herein a polymeric mesh suitable for use as a spacer in a membrane module in water treatment application, said mesh being at least partially coated with LIG.

A spiral-wound electrodialysis module includes an inner electrode positioned about a central axis and an outer electrode surrounding the inner electrode. Ion exchange membranes are arranged in a stack, and each membrane extends in a spiral outward from an inner position proximate the inner electrode to an outer position proximate the outer electrode. The spirals expand outward at a greater-than-linear rate as a function of angle along a length of the spiral from the inner positions to the outer positions.

Provide is a reverse osmosis membrane device that is capable of treating raw water containing membrane-fouling substance in large quantities, such as MBR-treated water, in a stable manner while preventing decreases in permeate flow rate, and a method for operating thereof. A method for operating a reverse osmosis membrane device that treats raw water containing high-molecular-weight organic matter, wherein the raw water contains high-molecular-weight organic matter having a molecular weight of 10,000 or more at a concentration of 0.01 ppm or more, wherein the reverse osmosis membrane device is equipped with a spiral-type reverse osmosis membrane element that has a membrane surface area satisfying the below formula (1), and wherein the reverse osmosis membrane device is operated at a permeate flux of 0.6 m/d or less:
membrane surface area(m.sup.2)?n.sup.2?(11/16)(1)
wherein n represents a diameter (inches) of the reverse osmosis membrane element.

The present invention relates to a reverse osmosis filter module including an improved feed spacer, and more particularly, to a reverse osmosis filter module including an improved feed spacer, in which spiral filaments are repeatedly positioned to form the feed spacer, such that a flow of a liquid to be supplied to the feed spacer is concentrated on a surface of a reverse osmosis membrane to effectively mitigate concentration polarization.

The present invention relates to a filter element and a method for manufacturing thereof. The method comprises: Providing the core tube; and rolling a membrane around the core tube. The membrane comprises a porous substrate and a filter layer on top of the porous substrate. The present invention also relates to the corresponding filter element. The filter element relating to the present invention is able to accommodate more membranes inside the same volume, resulting in high throughput and high salt rejection.

Gas separation membranes as may be used in separating gaseous materials from one another and methods of forming the membranes are described. The separation membranes include polymer-grafted nanoparticles (GNPs) as a platform and a relatively small amount of free polymer. The free polymer and the polymer grafted to the nanoparticles have the same chemical structure and similar number average molecular weights. The gas separation membranes can exhibit high ideal selectivity and can be used in a variety of applications, such as carbon capture.

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.