| 摘要 |
PROBLEM TO BE SOLVED: To provide a water treatment method and apparatus which can improve separation performance and maintainability for water treatment, and can perform efficient filtration using a separation membrane. SOLUTION: This method carries out water treatment by the filtration using the separation membrane 3. The separation membrane 3 is made of vinyl chloride-based resin and/or chlorinated polyethylene to which hydrophilicity is given. The filtration is carried out while maintaining the concentration of a membrane surface contamination preventing agent in water to be treated or membrane permeate of the separation membrane within a range capable of preventing the propagation of microorganisms. It is desirable that the separation membrane has such a permeability that pure water flux at an operating pressure of 0.1 MPa is equal to or larger than 5 m<SP>3</SP>/m<SP>2</SP>/day (at a water temperature of 25°C). The separation membrane can be made of a material with hydrophilicity derived by adding a compound with a hydrophilic group to vinyl chloride-based resin or chlorinated polyethylene and reacting them with each other. The separation membrane is a hollow fiber membrane, and it is desirable that tensile breaking strength per one hollow fiber is equal to or larger than 3.5 N. COPYRIGHT: (C)2007,JPO&INPIT
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