SEPARATION MEMBRANE FOR SALTWATER DESALINATION PRETREATMENT AND SALTWATER DESALINATION PRETREATMENT DEVICE

摘要

Provided are a separation membrane for saltwater desalination pretreatment and a saltwater desalination pretreatment device with which it is possible to remove TEP at a high removal rate while maintaining a fast current speed and constantly feeding a sufficient amount of raw water to an RO membrane without raising pressure. Also provided is a saltwater desalination method. The separation membrane for saltwater desalination pretreatment is used for pretreatment prior to saltwater desalination using a reverse osmosis membrane. The standard flux A, which is defined as the maximum flux with which P2 < 1.5 × P1 can be satisfied between the average membrane pressure difference P1 during the first 30 minutes and the average membrane pressure difference P2 during the 30 minutes once 120 minutes have passed when filtration is being performed at a constant flux, is 2 m/d or greater and the saccharide removal rate B or carbon particle removal rate C as defined by the following formula is 0.3 or greater, preferably 0.5 or greater. Saccharide removal rate B = (1 - filtered water saccharide content/raw water saccharide content) Carbon particle removal rate C = 1 - (filtered water POC/raw water POC), where POC = the suspended organic carbon content (difference between total organic carbon content and soluble organic carbon content)