Provided is a water-treatment membrane including a porous support; and a polyamide active layer including chlorine on a surface thereof, wherein CIE L*a*b* color coordinate values after storing for 30 days or longer at 25 C. to 80 C. satisfy Equation 1 to Equation 3:

91<L*<97 <Equation 1>

1.5<a*<1.5 <Equation 2>

1.5<b*<8 <Equation 3>

of the present disclosure, a water-treatment module including the same, and a method for manufacturing the same.

A filtration membrane coating comprising a hydrophilic polymer, a surfactant, and one or more charged compounds, each containing one or more sulfonate functionalities and one or more linkable functionalities selected from the group consisting of amine, monochlorotriazine, and dichlorotriazine. The hydrophilic polymer and surfactant form a thin primer layer which is also superhydrophilic. The primer layer improves flux, and enables improved adhesion of the one or more charged compounds, which form a charged dye layer on top of the primer layer when enhances rejection of charged divalent ions. The coating can be applied while the membrane is packaged in its final form, such as in a spiral wound or other configuration.

A system and method to increase surface friction across a hydrophobic, anti-fouling, and oleophobic coated substrate. The substrate has a hydrophobic surface defined by a surface friction. The system works to increases the surface friction, or roughness, across the hydrophobic surface. The increase in surface friction is accomplished by generating power through an ion source to create an ion cloud. The ion cloud is generated in proximity to the substrate. The ions interact with the hydrophobic surface to create a roughing effect thereon. A gas carrier device introduces an inert carrier gas through the ion cloud to increase density of the ions, which in turn increases surface friction. The system is variable, selectively increasing and decreasing surface friction by: varying the duration that the hydrophobic surface is exposed to the ion cloud; varying power applied to ion source; and varying distance between the ion cloud and the hydrophobic surface.

A conventional media filter such as a gravity sand filter is converted into a membrane filter. The media is removed and replaced by immersed membrane modules. Transmembrane pressure is created by a static head pressure differential, without a suction pump, thereby creating a membrane gravity filter (MGF). Preferred operating parameters include transmembrane pressure of 5-20 kPa, 1-3 backwashes per day, and a flux of 10-20 L/m.sup.2/h. The membranes are dosed with chlorine or another oxidant, preferably at 700 minutes*mg/L as Cl.sub.2 equivalent per week or less. The small oxidant does is believed to provide a porous biofilm or fouling layer without substantially removing the layer. The media filter may be modified so that backwash wastewater is removed from near the bottom of the tank rather than through backwash troughs above the membrane modules. Membrane integrity testing may be done while the tank is emptied after a backwash.

This invention relates generally to a chitosan-graphene oxide membrane and process of making the same. The nanocomposite membrane can filter water and remove contaminants without fouling like other commercially-available polymer-based water filters. The membrane can be used as a flat sheet filter or can be engineered in a spiral filtration module. The membrane is scalable and tunable for many water contaminants including pharmaceuticals, pesticides, herbicides, and other organic chemicals. The membrane uses chitosan, which is low-cost, renewable biopolymer typically considered to be a waste product and the second most abundant biopolymer on Earth, thus making the membrane an environmentally-friendly product choice.

This disclosure relates to the use of a hydrophobic hollow fiber filter for the filtration of cell cultures and other biological perfusions, due to its resistance to fouling, as well as the ability to filter solutions with a high solid content. A hydrophobic hollow fiber filter may be used within a filter housing in conjunction with a process vessel and a traditional separation system. When the system is used with alternating tangential flow or tangential flow filtration, the hydrophobic hollow fiber filter results in more effective filtration of the filtrate, leading to greater concentration of the retentate, even in solution containing high levels of solids.

A hybrid membrane, particularly of polyacrylonitrile (PAN)/graphene oxide (GO)/SiO.sub.2, separates oil and water even from emulsions. The membrane can be made by one-step electrospinning, adding GO and SiO.sub.2 nanofillers in PAN in various concentrations. The nanofillers may be uniformly embedded in the nanofibrous structure of the electrospun hybrid membrane, with GO mainly embedded inside the PAN nanofibers and may cause knots, and/or SiO.sub.2 nanoparticles embedded on the nanofiber surface and may form micro-nano fiber surface protrusions. Hierarchical structures formed can have enhanced hydrophilicity due to oxygen-containing groups on both SiO.sub.2 and GO, and have >99% oil rejection from oil-water emulsions. Separation flux and phase rejection of gravity separation may be enhanced by incorporation of nanofillers, which may also enhance membrane mechanical properties. Separated water flux may be enhanced from 2600 (pure PAN) to 3151 Lm.sup.2h.sup.1 for the hybrid.

The present invention relates to a superhydrophilic biodegradable cross linked foam membrane and a process for preparation of said foam membrane from a seaweed polysaccharides by blending with amino biopolymers/amino acids/proteins/amino compounds followed by crosslinking with a naturally occurring cross linker, genipin. The foam membrane can be used as a substitute for synthetic membrane for varied applications including membrane separation for oil-water emulsions, oil-water mixtures and other aqueous-organic mixtures under ambient conditions. These foam membranes can be recycled and reused more than three times without considerable decrease in flux rate and stability. The separation methodology of the mixtures using the foam membrane of the present invention is gravity-driven and therefore, simple and energy-efficient.

The present specification provides a method for manufacturing a water-treatment separation membrane, the method comprising: preparing a porous support; forming a polyamide active layer on the porous support by using an interfacial polymerization of an aqueous solution comprising an amine compound and an organic solution comprising an acyl halide compound; and coating a coating solution comprising a random copolymer comprising the monomers represented by Chemical Formulae 1 to 3 onto the polyamide active layer, in which a content of the random copolymer is 0.5 wt % to 2 wt % based on a total weight of the coating solution, a water-treatment separation membrane manufactured by using the same, and a water treatment module comprising the water-treatment separation membrane.

A method for filtering gas includes providing a gas filtration structure, and the gas filtration structure includes a porous support and a first gas filtration film pair on the porous support, wherein the first gas filtration film pair includes a first hydrogen permeation layer and a first calcinated layered double hydroxide (c-LDH) layer, and the first hydrogen permeation layer is disposed between the porous support and the first c-LDH layer. The method also provides a hydrogen-containing mixture gas over the first gas filtration film pair, and collects hydrogen under the porous support.