Chemical cleaning of reverse osmosis membrane fouled by wastewater

In water and wastewater treatment processes, membrane cleaning is of paramount economic and scientific importance and has significant impact on process operations. In this study, FT-30, hydrophilic polyamide membrane was used for treatment of industrial wastewater.The membrane was fouled with organic and inorganic matters for 540 min and then, cleaned with different chemical solutions to dissolve the deposits from the membrane surface.The cleaning agents were among a wide variety of chemicals including acids (HCl, HNO3, and H2SO4), base (NaOH), complexing agent (EDTA), surfactant (SDS), and their combination. To achieve high cleaning efficiency, the effects of physical factors (velocity, temperature and time) were studied. Resistance removal (RR) and flux recovery (FR) were used for demonstration of the cleaning efficiency. The result showed that the acids were not effective in recovering the flux, however, the two stages caustic and detergent cleaning including NaOH-SDS followed by acid provided effective recovery.