A novel high-flux thin film composite reverse osmosis membrane modified by polysaccharide supramolecular assembly

摘要

Thin film composite reverse osmosis (TFC RO) membrane is widely used in desalination and water reuse applications. With increasing capacity of Reverse Osmosis desalination all over the world, the increasing green-house gas emission for the required power is a cause of concern. TFC RO membrane is composed of the top polyamide layer over which, the linear polysaccharide such as chitosan can bind after activating the surface with oxidizing agent. The present paper analyzes the novel protocol of controlled oxidation of TFC RO membrane by exposing the same to potassium per sulfate with varying concentration of chitosan followed by sodium hypochlorite and sodium hypochlorite followed by potassium per sulfate with varying concentration of chitosan. The optimum performance was obtained when TFC RO membrane was exposed to 1 potassium persulfate with 1000 mg/L chitosan solution followed by 1000 mg/L sodium hypochlorite. Reversing order of the treatment resulted in the decline in permeance of the membrane. The reason of improvement in permeance is super-hydrophilic surface formed by oxidation of chitosan over polyamide surface. Thus, this article demonstrates the novel protocol of significantly improving the flux of TFC RO membrane and thereby reducing the energy consumption. (c) 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45026.