Abstract: A seawater desalination method of the present invention includes the steps of: obtaining ultrafiltration membrane-treated water by subjecting seawater (2) to an ultrafiltration membrane treatment; obtaining membrane bioreactor-treated water by subjecting organic wastewater (1) to a membrane bioreactor treatment; obtaining mixed water by mixing the ultrafiltration membrane-treated water and the membrane bioreactor-treated water; obtaining ultraviolet irradiation-treated water by subjecting the mixed water to an ultraviolet irradiation treatment; and subjecting the ultraviolet irradiation-treated water to a reverse osmosis membrane treatment.

Abstract: A seawater desalination method of the present invention includes the steps of obtaining ultrafiltration membrane-treated water by subjecting seawater (2) to an ultrafiltration membrane treatment; obtaining membrane bioreactor-treated water by subjecting organic wastewater (1) to a membrane bioreactor treatment; obtaining mixed water by mixing the ultrafiltration membrane-treated water and the membrane bioreactor-treated water; obtaining ultraviolet irradiation-treated water by subjecting the mixed water to an ultraviolet irradiation treatment; and subjecting the ultraviolet irradiation-treated water to a reverse osmosis membrane treatment.

Abstract: It is an object of the present invention to provide a composite semipermeable membrane having an excellent resistance property to contamination, particularly an excellent resistance property to microbial contamination, and a water treatment method using the composite semipermeable membrane. The present invention relates to a composite semipermeable membrane comprising a skin layer formed on the surface of a porous support and containing a polyamide-based resin obtained by reacting a polyfunctional amine component with a polyfunctional acid halide component, wherein an antibacterial layer containing a silver-based antibacterial agent and a polymer component is formed on the skin layer directly or with other layer interposed therebetween, and the weight ratio between the silver-based antibacterial agent and the polymer component in the antibacterial layer is 55:45 to 95:5 (silver-based antibacterial agent:polymer component).

Abstract: It is an object of the present invention to provide a composite semipermeable membrane having an excellent resistance property to contamination, particularly an excellent resistance property to microbial contamination, and a water treatment method using the composite semipermeable membrane. The present invention relates to a composite semipermeable membrane comprising a skin layer formed on the surface of a porous support and containing a polyamide-based resin obtained by reacting a polyfunctional amine component with a polyfunctional acid halide component, wherein an antibacterial layer containing a silver-based antibacterial agent and a polymer component is formed on the skin layer directly or with other layer interposed therebetween, and the weight ratio between the silver-based antibacterial agent and the polymer component in the antibacterial layer is 55:45 to 95:5 (silver-based antibacterial agent:polymer component).

Abstract: A feed side passage material is provided in which sufficient antibacterial activity is obtained even in the spaces among constituent yarns and which hence can effectively prevent biofouling. Also provided is a spiral separation-membrane element employing the feed side passage material. The feed side passage material, which is for use in a spiral separation-membrane element, is a feed side passage material in a net form constituted of yarns (1 and 2) containing a chlorophenol compound antibacterial. The spiral separation-membrane element comprises a perforated hollow core tube and, wound therearound, one or more separation membranes, one or more feed side passage materials, and one or more permeate side passage materials. The element is characterized in that the feed side passage materials each is said feed side passage material.

Abstract: It is an object of the present invention to provide a process for producing, easily and at a low cost, a composite semipermeable membrane having excellent contamination resistance, especially microbial contamination resistance, and a composite semipermeable membrane produced by the process. The process for producing a composite semipermeable membrane of the present invention comprises forming a skin layer including a polyamide resin obtained by a reaction between a polyfunctional amine component and a polyfunctional acid halide component on the surface of a porous support; forming a polymer layer (A) including a silver salt compound on the skin layer directly or through other layers; and reducing the silver salt compound to precipitate metal silver in the polymer layer (A) and/or on the surface thereof.

Abstract: It is an object of the present invention to provide a composite semipermeable membrane having an excellent resistance property to contamination, particularly an excellent resistance property to microbial contamination, and a water treatment method using the composite semipermeable membrane. The present invention relates to a composite semipermeable membrane comprising a skin layer formed on the surface of a porous support and containing a polyamide-based resin obtained by reacting a polyfunctional amine component with a polyfunctional acid halide component, wherein an antibacterial layer containing a silver-based antibacterial agent and a polymer component is formed on the skin layer directly or with other layer interposed therebetween, and the weight ratio between the silver-based antibacterial agent and the polymer component in the antibacterial layer is 55:45 to 95:5 (silver-based antibacterial agent:polymer component).