Reverse osmosis membrane cleaning agent, cleaning liquid, and cleaning method

摘要

This reverse osmosis (RO) membrane cleaning agent, which effectively removes contaminants that cannot be sufficiently removed by conventional cleaning agents, when a RO membrane used to treat water, particularly an aromatic polyamide-based RO membrane used to desalinate seawater, becomes contaminated, and the performance thereof in terms of the permeation flux, differential pressure, salt rejection rate, and the like is reduced, includes an aldonic acid and/or a salt thereof. Also provided is a method in which the cleaning agent or a cleaning liquid is used to clean a RO membrane. Accordingly, the heavy metal chelating action of the aldonic acid and/or salt thereof, the contaminant release effect of an anionic surface active agent when an anionic surface active agent is also employed, and the wetting/swelling effect of a polyol compound on contaminants when a polyol compound having a molecular weight of not more than 1000 is also employed, are added to the releasing effect and hydrolyzing effect of alkaline conditions during cleaning, and act synergistically to improve the alkaline cleaning effect.