Patent ID: 6406626
Filing Date: 2002-06-18
Classification: B01D,C02F

Abstract:
A composite semipermeable membrane, comprising a microporous support membrane and a membrane layer formed thereon by polycondensation, the membrane layer comprising a cross-linked polyamide ultra-thin membrane layer formed by polycondensation of a polyfunctional amine, a polyfunctional acid halide and a polyfunctional acid anhydride halide,the composite semipermeable membrane exhibiting a rate of flow of water permeate at an operating pressure of 0.3 MPa, a temperature of 25Â° C. and a pH of 6.5 in the range of from 0.8 to 4.0 m3/m2.day and providing a percentage of humic acid removal of at least 98%, the ultra-thin membrane layer having a carboxyl group concentration analyzed using X-ray photoelectron spectroscopy (ESCA) of at least 0.02 but less than 0.06.