Composite reverse osmosis membrane having a separation layer with polyvinyl alcohol coating and method of reverse osmotic treatment of water using the same

摘要

A reverse osmosis composite membrane that has a high salt rejection, a high water permeability, and a high fouling tolerance, and permits practical desalination at a relatively low pressure is provided by coating the surface of a reverse osmosis membrane of aromatic polyamide with polyvinyl alcohol (PVA), for example, and controlling the surface zeta potential of the separation layer within±10 mV at pH 6. This reverse osmosis composite membrane is electrically neutral and controls the electrical adsorption of membrane-fouling substances having a charge group present in water. Therefore, a high separation property can be maintained without fouling the membrane even if water containing a surfactant or a transition metal component is supplied as raw water.