▎ 摘　　要

NOVELTY - Preparing nanofiltration membrane involves synthesizing graphene oxide, configuring graphene oxide as a dispersion, and using ultrafiltration membrane separation to obtain a small-sized graphene oxide dispersion. The ultrafiltration membrane base membrane is washed, and the cleaned ultrafiltration membrane base membrane is obtained after drying. The aqueous phase monomer is dissolved in water to form a monomer aqueous solution, and a small-sized graphene oxide dispersion is added to the monomer aqueous solution to obtain an aqueous phase reaction solution. The organic phase monomer is dissolved in an organic solvent by ultrasound to obtain an organic solution. USE - Method for preparing nanofiltration membrane for reducing chromaticity of sewage. ADVANTAGE - The method enables to prepare nanofiltration membrane, which has high cut-off molecular weight, good hydrophilicity, high flux, and the nano-filtration membrane and ultra-filtration basement membrane combined novel nano-filtration membrane tightly, the nano-filter membrane is mainly used in the water to remove the chroma type pollutant. DETAILED DESCRIPTION - Preparing nanofiltration membrane for reducing chromaticity of sewage involves synthesizing graphene oxide, configuring graphene oxide as a dispersion, and using ultrafiltration membrane separation to obtain a small-sized graphene oxide dispersion. The ultrafiltration membrane base membrane is washed, and the cleaned ultrafiltration membrane base membrane is obtained after drying. The aqueous phase monomer is dissolved in water to form a monomer aqueous solution, and a small-sized graphene oxide dispersion is added to the monomer aqueous solution to obtain an aqueous phase reaction solution. The organic phase monomer is dissolved in an organic solvent by ultrasound to obtain an organic solution. The cleaned ultrafiltration membrane base membrane is set on a two-way coating device, under a pressure condition of 0.2-0.4 mega pascals, the aqueous phase solution is passed through the ultrafiltration base membrane multiple times, and then the residual water phase on the surface of the base membrane is purged and removed. The organic phase reaction solution is passed to the interface polymerization reaction on the surface of the ultrafiltration membrane base membrane, the ultrafiltration membrane is placed in a vacuum drying box after the reaction for heat treatment to obtain a nanofiltration membrane that reduces the color of sewage. The aqueous monomer is one or more mixtures of piperazine, m-phenylenediamine, p-phenylenediamine, and hyperbranched amines, and the organic phase monomer is one or more mixtures of trimesyl chloride, phthaloyl chloride, terephthaloyl chloride, and isophthaloyl chloride.