Application of hydrophilic macromolecules on thin film composite polyamide membranes for performance restoration

► Salt rejection of degraded RO membranes is improved by treatment with polymers. ► Compounds used are Polyvinyl methyl ether, polyvinyl pyrrolidone, and polyvinyl alcohol. ► Treatment by solutions of polymeric additives is followed by tannic acid application. ► The treatment can be performed online without interrupting plant operation.