The object of the present invention is to provide a spiral membrane element that can make a composite semipermeable membrane high in effective membrane area, and that can restrain the composite semipermeable membrane from being lowered in rejection ratio by a deformation of this membrane while ensuring the flow rate of a permeation liquid flowing in a permeation-side flow-channel sufficiently. The spiral membrane element comprises a layered body which comprises a composite semipermeable membrane, a supply-side flow-channel member, and a permeation-side flow-channel member; and the permeation-side flow-channel member comprises a tricot knitted fabric having a plurality of ribs each formed by repeating loops in a linear form in a longitudinal direction, and a plurality of grooves present between the ribs; has a membrane support index of 60 to 135, the membrane support index being calculated in accordance with the specified numerical relationship.

Disclosed herein are multi-layer structures comprising a first composite layer disposed over a second composite layer, wherein the first composite layer contains a first active material dispersed in a first polymer containing an elastomeric polymer and the second composite layer contains a second polymer which may have a second active material dispersed therein, wherein the first active material chemically or physically interacts with at least one toxic chemical and is selected from the group consisting of metal-organic frameworks (MOFs), metal oxides, metal hydroxides, zeolites, and combinations thereof, and wherein the active material and the second active material (if present) are the same as or different from each other, and the first polymer and second polymer are the same as or different from each other, subject to the proviso that the first composite layer and the second composite layer compositionally differ from each other in at least one respect.

A device for filtering and separating pressurized liquid mixtures by means of a membrane includes a substantially pressure-tight container in which the membranes are accommodated in a pressure-tight manner. The container has at least one intake for the mixture, as well as at least one outlet for the permeate separated from the mixture by means of the membranes, and at least one outlet for the retentate, also referred to as a concentrate. The pressure-tight container is made of plastic.

A cord for supporting a biofilm has a plurality of yarns. At least one of the yarns comprises a plurality of hollow fiber gas transfer membranes. At least one of the yarns extends along the length of the cord generally in the shape of a spiral. Optionally, one or more of the yarns may comprise one or more reinforcing filaments. In some examples, a reinforcing yarn is wrapped around a core. A module may be made by potting a plurality of the cords in at least one header. A reactor may be made and operated by placing the module in a tank fed with water to be treated and supplying a gas to the module. In use, a biofilm covers the cords to form a membrane biofilm assembly.

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.

A cord for supporting a biofilm has a plurality of yarns. At least one of the yarns comprises a plurality of hollow fiber gas transfer membranes. At least one of the yarns extends along the length of the cord generally in the shape of a spiral. Optionally, one or more of the yarns may comprise one or more reinforcing filaments. In some examples, a reinforcing yarn is wrapped around a core. A module may be made by potting a plurality of the cords in at least one header. A reactor may be made and operated by placing the module in a tank fed with water to be treated and supplying a gas to the module. In use, a biofilm covers the cords to form a membrane biofilm assembly.

A hollow fiber membrane is formed by embedding a braid having a spiral open weave of monofilaments only, to avoid a whiskering problem. The open weave is characterized by contiguous, circumferential, rhomboid-shaped areas of polymer film separated by monofilaments. When the braid is supported on a plasticized PVA cable having a scalloped periphery, the braid can be infiltrated with membrane polymer which, when coagulated, embeds the braid positioning it around the lumen. The embedded spiral weave, free of any circumferentially constricting monofilament, allows the membrane to be biaxially distensible. The membrane has give not only in the axial or longitudinal direction but also in the radial direction. Give in the radial direction permits soiled membranes to be backwashed under higher pressure than in a comparable braid which is not radially distensible.

Disclosed herein are composite membranes comprising an omniphobic substrate having a reentrant structure. The omniphobic substrate comprises a plurality of pores, the plurality of pores forming the reentrant structure. The omniphobic substrate further comprises a surface, the surface being coated with a dual functional layer that is hydrophilic in air and oleophobic under water, such that the composite membrane has a top portion and a bottom portion, the top portion comprising the coated surface of the omniphobic substrate, such that the top portion of the composite membrane is hydrophilic in air and oleophobic under water and the bottom portion of the composite membrane is omniphobic. The composite membrane can be antiwetting and/or antifouling in the presence of a hydrophobic contaminant, an amphiphilic contaminant, or a combination thereof. The composite membranes can be used for membrane distillation of a contaminated brine solution.

The invention relates to obtaining a nanofiber membrane by coating a hollow braided rope (3) with a nanofiber layer (2), to the usage of said tubular nanofiber membrane as a support layer membrane, and to the fabrication of forward osmosis membrane by coating the surface thereof with thin composite film (1). Particularly, a tubular nanofiber forward osmosis membrane used in water & waste water treatment and desalination processes with high water flux, low reverse salt flux, as well as a low tendency of fouling, and the manufacturing method thereof are disclosed herein.

The present invention relates to a method of preparing a nanocomposite membrane, comprising: (a) providing a nanocomposite solution comprising a polymer solution and nanomaterials; (b) subjecting the nanocomposite solution to a cold water bath to produce the nanocomposite membrane in a gel-like form; and (c) subjecting the gel nanocomposite membrane to a heat treatment to solidify the nanocomposite membrane, wherein the nanomaterials are dispersed within the polymer matrix of the nanocomposite membrane.