A high-flux composite nanofiltration (NF) membrane with an electrical double layer (EDL) and a preparation method thereof are provided. The high-flux composite NF membrane includes: a charged support membrane and a charged separation layer, where a charge carried by the support membrane or the separation layer is a positive charge, a negative charge, or an amphiprotic charge. The high-flux composite NF membrane with an EDL solves the technical problem that the composite NF membrane in the prior art has an unsatisfactory retention rate and a limited application range due to a small charge quantity.

An air remediation device includes a housing including an internal chamber, an inlet, an outlet, and a potting material dividing said internal chamber into a first compartment and a second compartment. At least one hollow fiber membrane is supported by the potting material and held in the first compartment. Airborne viral particles are directed (a) through the inlet into the first compartment and then (b) through the at least one hollow fiber membrane, where the airborne viral particles are captured to produce treated air, and then the treated air is directed (c) through the second compartment before being exhausted from the housing through the outlet.

A hollow fiber membrane of the present invention is a hollow fiber membrane having an outer surface and an inner surface, wherein the inner surface has a zebra stripe pattern in which dense portions and porous portions are alternately formed in the longitudinal direction, and the outer surface has a maximum pore size of about 1 μm or less (≤about 1 μm), and wherein the hollow fiber membrane has a water permeability (flux) of ≥about 1,300 LMH/bar to ≤about 5,000 LMH/bar.

A concentration membrane for use in concentrating biological particles, including: a hydrophilic composite porous membrane including: a porous substrate; and a hydrophilic resin with which at least one main surface and inner surfaces of pores of the porous substrate are coated, the hydrophilic composite porous membrane having a ratio t/x of a membrane thickness t (m) to an average pore diameter x (m), as measured with a perm porometer, of from 50 to 630. A concentration device 10 for biological particles 50 including: a housing 20 having an inlet 21 and an outlet 22, in which, due to a differential pressure between the inlet 21 and the outlet 22, a liquid to be treated 40 containing biological particles 50 and water is injected from the inlet 21 and discharged from the outlet 22; a concentration membrane 30 provided to separate the inlet 21 and the outlet 22 from each other in the housing 20, the concentration membrane 30 being a hydrophilic porous membrane onto which the biological particles 50 are not adsorbed, the concentration membrane 30 allowing an effluent 42, which is a liquid having a concentration that is a concentration of the biological particles 50 subtracted from a concentration of the liquid to be treated 40, to permeate from a surface on a side of the inlet 21 to a surface on a side of the outlet 22; and a concentration space portion 24 which is a space on an upstream side of the concentration membrane 30 in the housing 20 and stores a concentrated liquid 41 which is a liquid having a concentration that is a concentration of the biological particles 50 added to a concentration of the liquid to be treated 40 by the concentration membrane 30.

The present disclosure relates to a microporous hollow fiber filter membrane having a large inner diameter and a thin wall. The fiber can be used for sterile filtration of liquids or removal of particles from liquids. The disclosure further relates to a method for producing the membrane and a filter device comprising the membrane.

The present invention provides a porous membrane for water treatment, comprising: a high molecular weight polyethylene, a water-soluble polymer and an antioxidant, the high molecular weight polyethylene having an average molecular weight of 1.0×10.sup.5 to 10.0×10.sup.6 and a density of 0.940 to 0.976 g/cm.sup.3; wherein, the weight of the water-soluble polymer is 5 to 50 parts, the weight of the antioxidant is 0.1 to 10 parts, based on 100 parts of the weight of the high molecular weight polyethylene. The porous membrane for water treatment prepared by the present invention has a thickness of 5 to 30 μm, a pore size of 10 to 100 nm, a porosity of 20 to 60%, and a surface contact angle of 30° to 95°. The porous membrane according to the present invention has good durability, simple preparation process, and relatively thin thickness, a uniform pore size distribution and small pore size, good hydrophilicity, as well as good filtration and adsorption effect.

A porous support for nano-thickness membranes of less than 100 nanometers local surface roughness, suitable for the support of single-layer membranes of from about 1 to 500 nanometers in thickness, and for multiple layer membranes of up to about 2000 nanometers in aggregate thickness. The support also has a surface pore size of less than 100 nanometers and a surface porosity of less than 50 percent.

Disclosed is a method for treating wastewater containing heavy metal. First, the wastewater containing heavy metal is subjected to a homogenization treatment, such that the water quality of the wastewater containing heavy metal from different processes is homogenized. The homogenized wastewater containing heavy metal is subjected to an anaerobic-aerobic circulating treatment in a membrane bioreactor (2), in which heavy metal ions are reduced by the action of microorganisms in the anaerobic treatment process. The membrane bioreactor (2) is filled with a hollow fiber membrane (3) containing a quinone group, which serves as an electron mediator that can accelerate the enzymatic reduction of heavy metal ions during the anaerobic treatment. During the aerobic treatment, the COD and SS in the wastewater are further removed.

Provided is a filter screen having a plurality of slots, each slot having a longest principal axis A1 that has a length L, and each slot having a second axis A2 that is perpendicular to A1 and that has a length W, wherein the distance between adjacent slots in the direction of the axes A2 is XP; wherein XP is greater than W; wherein the distance between adjacent slots in the direction of the axes A1 is YP; either wherein L is 800 micrometers or less and XP is 350 micrometers or less, or wherein L is 1600 μm or less and XP is 180 μm or less.

Also provided is a method of filtering feed water using such a filter screen.

The present invention aims to provide a method for preparing exosomes comprising: (i) a step for ultrafiltering a sample containing at least one exosome; and (ii) a step for subjecting the sample that can be obtained from step (i) to anion exchange column chromatography.