Abstract: An efficient method is provided for cleaning hollow fiber membrane modules, the method being capable of efficiently removing substances accumulated inside hollow fiber membrane modules. The internal liquid on the raw liquid side of the hollow fiber membrane module (3) is discharged from a lower end face nozzle (19) of the hollow fiber membrane module (3) while air-cleaning is performed. The method for cleaning hollow fiber membrane modules is characterized in that the rate of liquid discharge from the lower end face nozzle of the hollow fiber membrane module (3) when discharging the internal liquid from the lower end face nozzle is adjusted so that the air supplied from the lower end face nozzle of the hollow fiber membrane module (3) through the aeration holes is supplied to the hollow fiber membrane module (3).

Abstract: A method of sewage treatment includes: immersing a separation membrane module into sewage, wherein the separation membrane module has a plurality of separation membrane elements, each having a supporting plate, a separation membrane and a filtered water outlet; separating water into filtered water and suspended solids by having the water permeated through the separation membrane; and having the filtered water flow toward the exterior from the filtered water outlet; wherein the separation membrane has a nonwoven fabric and a porous resin layer on at least one surface of the nonwoven fabric; and a part of the resin permeates into the nonwoven fabric to form a composite layer with the nonwoven fabric.

Abstract: An efficient method is provided for cleaning hollow fiber membrane modules, the method being capable of efficiently removing substances accumulated inside hollow fiber membrane modules. The internal liquid on the raw liquid side of the hollow fiber membrane module (3) is discharged from a lower end face nozzle (19) of the hollow fiber membrane module (3) while air-cleaning is performed. The method for cleaning hollow fiber membrane modules is characterized in that the rate of liquid discharge from the lower end face nozzle of the hollow fiber membrane module (3) when discharging the internal liquid from the lower end face nozzle is adjusted so that the air supplied from the lower end face nozzle of the hollow fiber membrane module (3) through the aeration holes is supplied to the hollow fiber membrane module (3).

Abstract: A membrane filtration method and membrane filtration device including a pre-treatment membrane module that filters raw water with a filtration membrane and obtains pre-treated water; a reverse osmosis membrane module that filters the pre-treated water obtained from the pre-treatment membrane module with a reverse osmosis membrane and obtains permeate and retentate; a communicating tube channel that directly joins the pre-treated water outlet of the pre-treatment membrane module and the pre-treated water inlet of the reverse osmosis membrane module; and a branch tube channel that branches from the communicating tube channel and diverts a portion of the pre-treated water flowing in the communicating tube channel from the communicating tube channel. The filtration membrane of the pre-treatment membrane module is backwashed using the pre-treated water that has been diverted by the branch tube channel.

Abstract: The present invention provides a hollow fiber membrane filtration device including a hollow fiber membrane module in which a hollow fiber membrane bundle formed of a plurality of hollow fiber membranes is inserted into a cylindrical case having a plurality of side nozzles at a side surface of the cylindrical case, provided with a water feed/drainage function, an upper-end nozzle on an upper-end face of the cylindrical case, provided with a water feed/drainage function and a lower-end nozzle on a lower-end face of the cylindrical case, provided with a water feed/drainage function, and at least one-sided end of the hollow fiber membrane bundle is fixed to the cylindrical case by bonding with resin in a position higher than any of positions of the plurality of side nozzles, in which at least two of the plurality of side nozzles are communicated with each other through a piping.

Abstract: This invention provides a hollow fiber membrane module which can reduce pressure loss in discharging water within a module and can reduce operating power. A hollow fiber membrane bundle is disposed within a cylindrical case having in its side face an opening part for the inflow/outflow of water, and the end of the hollow fiber membrane bundle is bonded at an axially outer position with respect to the opening for the inflow/outflow of water. A distribution holes is provided axially inward of the opening for the inflow/outflow of water and so as to surround the outer periphery of the hollow fiber membrane bundle, and grooves and/or corrugated protrusions are provided on the inner face of the distribution cylinder so as to be in communication with each other among the distribution holes.

Abstract: A method for manufacturing a porous membrane including a three-dimensional network structure and a spherical structure is provided. The method includes forming a porous membrane having a spherical structure, applying a resin solution onto at least one surface of the porous membrane having the spherical structure, followed by immersing the membrane in a solidification liquid, thereby forming the three-dimensional network structure on at least one surface of a porous membrane having the spherical structure.

Abstract: This invention provides a hollow fiber membrane module which can reduce pressure loss in discharging water within a module and can reduce operating power. A hollow fiber membrane bundle comprising a plurality of numbers of hollow fiber membranes are disposed within a cylindrical case having in its side face an opening part for the inflow/outflow of water, and the end of the hollow fiber membrane bundle is fixed by bonding at a position which is located in the axial direction of the cylindrical case at an outer position than the position of the opening part for the inflow/outflow of water on the side face of the cylindrical case.

Abstract: A method of sewage treatment includes: immersing a separation membrane module into sewage, wherein the separation membrane module has a plurality of separation membrane elements, each having a supporting plate, a separation membrane and a filtered water outlet; separating water into filtered water and suspended solids by having the water permeated through the separation membrane; and having the filtered water flow toward the exterior from the filtered water outlet; wherein the separation membrane has a nonwoven fabric and a porous resin layer on at least one surface of the nonwoven fabric; and a part of the resin permeates into the nonwoven fabric to form a composite layer with the nonwoven fabric.

Abstract: The object of the present invention is to provide a porous membrane having a high strength and excellent water permeability and rejection properties. The porous membrane of the present invention has both a three-dimensional network structure and a spherical structure. The porous membrane of the present invention is suitably used for water treatment membranes, battery separators, charged membranes, fuel cells, blood purification membranes, and the like.

Abstract: The object of the present invention is to provide a porous membrane having a high strength and excellent water permeability and rejection properties. The porous membrane of the present invention has both a three-dimensional network structure and a spherical structure. The porous membrane of the present invention is suitably used for water treatment membranes, battery separators, charged membranes, fuel cells, blood purification membranes, and the like.

Abstract: The object of the present invention is to provide a porous membrane having a high strength and excellent water permeability and rejection properties. The porous membrane of the present invention has both a three-dimensional network structure and a spherical structure. The porous membrane of the present invention is suitably used for water treatment membranes, battery separators, charged membranes, fuel cells, blood purification membranes, and the like.

Abstract: A separation membrane has a porous substrate and a porous resin layer on at least one surface of the porous substrate and the porous resin layer contains a resin. Part of the resin permeates through the porous substrate to form a composite layer.