Development of a chlorine-resistant polyamide nanofiltration membrane and its field-test results

For the development of chlorine-resistant nanofiltration membranes, a thin-film-composite membrane was prepared by the interfacial polymerization of N-phenylethylenediamine and 1,3,5-benzenetricarbonyl trichloride on a microporous polysulfone support substrate. The polymerization on the substrate surface was confirmed by Fourier transform infrared measurements, and membrane surface properties such as the roughness and zeta potential were characterized. Rejections of NaCl and isopropyl alcohol of the prepared membrane were 95 and 50%, respectively. The membrane showed much higher chlorine resistance than a commercial polyamide membrane when the membranes were immersed in art aqueous NaOCl solution. A field test was carried out with a spiral-type membrane module. Tap water was treated by this module for more than 70 days under the condition of continuous NaOCl injection. The prepared membrane module was quite stable, and no distinguished change in the rejection and flux was recognized. (C) 2007 Wiley Periodicals, Inc. J Appl Polym Sci 106: 4174-4179, 2007