SEPARATION MEMBRANE, SEPARATION MEMBRANE ELEMENT, SEPARATION MEMBRANE MODULE, SEWAGE TREATMENT APPARATUS, AND METHOD FOR MAKING THE SEPARATION MEMBRANE

摘要

A separation membrane having a porous substrate and a porous resin layer on at least one surface of the porous substrate and the porous resin layer contains a resin. Part of the resin permeates through the porous substrate to form a composite layer. At least one of the following relationships (1) and (2) is satisfied: (1) the porous resin layer has an average pore size in the range of 0.01 to 0.2 µm and a standard variation of the pore size of 0.1 µm or less at the surface, and (2) the porous resin layer has macrovoids having short diameters of 0.05xA or more wherein A represents the thickness of the porous substrate, and the rejection of microparticles having an average particle size of 0.9 µm is at least 90%. This separation membrane can be readily produced by a method for making a separation membrane according to the present invention.