N-chlorosuccinimide as a novel agent for biofouling control in the polyamide reverse osmosis membrane process

• NCS showed a potential as an effective biofouling control agent in RO process.
• NCS achieved higher inactivation of bacteria on biofilms than chlorine.
• There were no significant changes in membrane performance after NCS exposure.

One of the biggest challenges in reverse osmosis membrane process is formation of biofilms on membrane surface (biofouling) which significantly lowers membrane performance and shortens life cycle of the membrane. In an effort to find a more effective biocide to control biofouling, we investigated the potential of N-chlorosuccinimide (NCS) as a biofouling control agent in polyamide membrane. The results of this study show that there are no significant changes in the surface characteristics of polyamide membrane (measured by X-ray photoelectron spectroscopy (XPS) and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR)) when it is exposed to a high concentration of NCS (5000 mg/L as Cl2). Also, there were no significant changes in membrane performance based on permeate flux and salt rejection after exposure to the same concentration of NCS. Most importantly, inactivation of Pseudomonas aeruginosa PAO1 GFP biofilm cells by 10 mg/L of NCS was 2.2 log after 30 min, which is far greater than that of chlorine. Overall, the results of this study suggest that NCS is a promising novel agent for biofouling control in polyamide membrane processes due to its effective inactivation of biofilm cells on membrane and minimum effect on membrane structure and performance.