método para melhorar a retenção de membrana de osmose reversa, agente de tratamento para melhorar a retenção, e membrana de osmose reversa

摘要

A method capable of effectively improving a rejection of a reverse osmosis membrane without remarkably reducing a permeation flux, even if the membrane is seriously degraded. An aqueous solution containing a first organic compound having a molecular weight of less than 200, a second organic compound having a molecular weight of 200 to less than 500, and a third organic compound having a molecular weight of 500 or more is passed through the reverse osmosis membrane. The first organic compound is preferably an amino acid or an amino acid derivative. The total concentration of the first organic compound and the second organic compound and the concentration of the third organic compound are each preferably 1 to 500 mg/L.