▎ 摘　　要

NOVELTY - A composite nanofiltration membrane comprises reduced graphene oxide and substrate. USE - Composite nanofiltration membrane used for dye wastewater treatment (claimed), biomedicine and water processing field. ADVANTAGE - The method is non-toxic and pollution-free, and has simple operation, and mild reaction conditions. The membrane has good filtering property. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of the membrane comprising preparing graphene oxide film through Langmuir-Blodgett technique, transferring to substrate, repeatedly soaking and pulling, and subjecting to reduction reaction.