Nitto-denko Corporation

Yuuji Yamashiro

Yasuhiro Uda

Takahisa Konishi

Kouji Maruyama

Naoki Kurata

Satoru Ishihara

Shinya Nishiyama

Chiaki Harada

Hiroshi Iwahori

A seawater desalination method of the present invention includes the steps of: obtaining ultrafiltration membrane-treated water by subjecting seawater () to an ultrafiltration membrane treatment; obtaining membrane bioreactor-treated water by subjecting organic wastewater () 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.

Seawater desalination method

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).

Composite semipermeable membrane

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Osaka, Japan

Yuuji Yamashiro