Described herein is a method of using hollow fiber filter cartridge. The method includes: providing a hollow fiber filter cartridge inside or outside an environmental cleaning equipment; allowing a wastewater to enter the hollow fiber filter cartridge from an outside of the hollow fiber filter under no water pressure or low water pressure (such as under 30 gw/cm.sup.2); allowing the wastewater to cross a plurality of nanopores of the hollow fiber filter cartridge under no water pressure or low water pressure (such as under 30 gw/cm.sup.2) to produce a clean water; and allowing the environmental cleaning equipment to filter wastewater to produce clean water continuously, thereby improving cleaning efficiency and reducing water consumption.

There is provided a semi-crystalline polymer membrane, the membrane being a single-layer membrane and su-perwettable without provision of a coating or additives. There is also provided a method of forming the membrane comprising: depositing a solution on a substrate surface, the solution comprising a semi-crystalline polymer to form a nascent membrane; spraying a fluid on the nascent membrane; and immersing the nascent membrane in a non-solvent to form the semi-crystalline polymer membrane. In preferred embodiments, the fluid sprayed on the nascent membrane is selected from compressed air, water, a mixture of ethanol and water, or a solid suspension of ethanol/water/sodium chloride.

A forward osmosis membrane for seawater desalination and a method for preparing the same. The forward osmosis membrane has a composite membrane structure including a nonwoven fabric layer; a hydrophilic polymer layer; and a polyamide layer. The hydrophilic polymer layer formed on the nonwoven fabric layer facilitates an inflow of water from the feed water to the draw solution to enhance flux and realize high water permeability in the direction of osmosis. The polyamide layer not only secures contamination resistance and chemical resistance but also minimizes the back diffusion of salts of the draw solution in the direction of reverse osmosis. Hence, the forward osmosis membrane of the present invention is greatly useful for desalination of high-concentration seawater.

The apparatus for filtering and dispensing drinking water is disclosed which includes a container having an interior space with a dividing wall defining a first chamber for receiving unfiltered water and a second chamber for storing filtered drinking water, wherein a passage is formed through the interior wall adjacent a bottom surface of the container to provide fluid communication between the first and second chambers, and wherein at least one multi-layered filter pack is disposed across the passage to filter water flowing from the first chamber to the second chamber under force of gravity.

The apparatus for filtering and dispensing drinking water is disclosed which includes a container having an interior space with a dividing wall defining a first chamber for receiving unfiltered water and a second chamber for storing filtered drinking water, wherein a passage is formed through the interior wall adjacent a bottom surface of the container to provide fluid communication between the first and second chambers, and wherein at least one multi-layered filter pack is disposed across the passage to filter water flowing from the first chamber to the second chamber under force of gravity.

A hand-carry gravity-driven water filter with high throughput and water disinfection performance is formed. Membranes used for this water filter can be fabricated using electrospun method and non-solvent induced phase inversion method. A novel composite membrane structure (interwoven composite structure) was designed for further enhances water permeability and mechanical strength. The composite membrane can be composed of nanofibers with different diameter from the same polymer or different polymers. Membrane porosity and surface pore size can be controlled. Silver nanoparticles can be in-situ loaded on the surface of the membranes. The developed filter is effective for removal of a wide range of contaminants (e.g., pathogens, suspended solids and heavy metals). The purification process can be carried out under the drive of gravity (with an option for mechanically-enhanced filtration) without electricity.

A hand-carry gravity-driven water filter with high throughput and water disinfection performance is formed. Membranes used for this water filter can be fabricated using electrospun method and non-solvent induced phase inversion method. A novel composite membrane structure (interwoven composite structure) was designed for further enhances water permeability and mechanical strength. The composite membrane can be composed of nanofibers with different diameter from the same polymer or different polymers. Membrane porosity and surface pore size can be controlled. Silver nanoparticles can be in-situ loaded on the surface of the membranes. The developed filter is effective for removal of a wide range of contaminants (e.g., pathogens, suspended solids and heavy metals). The purification process can be carried out under the drive of gravity (with an option for mechanically-enhanced filtration) without electricity.

The present invention provides a separation membrane that is usable at a high temperature and a high pressure. The solvent-resistant separation membrane of the present invention has an average pore diameter of the separation membrane surface of 0.005 to 1 μm and includes a portion where a degree of cyclization (I.sub.1600/I.sub.2240) as measured by the total reflection infrared absorption spectroscopy is 0.5 to 50.

The present disclosure provides an ion-exchange membrane that includes a supporting substrate impregnated with an ion-exchange material. The supporting substrate includes an imprinted non-woven layer, and the imprinting includes a plurality of deformations at a surface density of at least 16 per cm.sup.2. The supporting substrate may lack a reinforcing layer. In some examples, the supporting substrate may include only a single layer of the imprinted non-woven fabric.

Provided are a polymer having a constituent component represented by formula (I) below, a method for producing the polymer, a diamine compound suitable as a raw material for the polymer, a gas separation membrane haying a gas separation layer including the polymer, and a gas separation module and a gas separation apparatus that have the gas separation membrane.

##STR00001##

In the formula (I), R.sup.A, R.sup.B, and R.sup.C represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a halogen atom. Herein, at least one of R.sup.A, R.sup.B, or R.sup.C represents an alkyl group having 1 to 4 carbon atoms or a halogen atom. The alkyl group having 1 to 4 carbon atoms is not trifluoromethyl and ** represents linking sites.