Seawater desalination pretreatment for separation membrane , seawater desalination pretreatment system , seawater desalination equipment and seawater desalination method

摘要

PROBLEM TO BE SOLVED: To provide a separation membrane for pretreatment of seawater desalination, an apparatus for pretreatment of seawater desalination and a method for seawater desalination by which sufficient amount of raw water can be constantly supplied to a reverse osmosis (RO) membrane by maintaining high flux and without raising pressure while removing TEP (transparent exopolymer particles) at a high removing ratio.SOLUTION: In the separation membrane for pretreatment of seawater desalination used for pretreatment of seawater desalination using the reverse osmosis membrane, filtration is carried out at a constant flux and standard flux A, which is defined as a maximum value of fluxes capable of satisfying P2≤1.5×P1 between average transmembrane pressure difference P1 at a period for initial 30 minutes and average transmembrane pressure difference P2 at a period for 30 minutes after 120 minutes have passed, is not less than 2 m/d and a saccharides removal rate B or a granular carbon removal rate C is not less than 0.3, more preferably not less than 0.5.