Seawater desalination plants, one of the solutions to the global shortage of fresh water, are now mainly using a reverse osmosis (RO) membrane method, which has energy saving potential, instead of the conventional evaporation method. The desalination performance of RO membranes degrades over time, and eventually they no longer satisfy the required desalination performance. In such cases, the degraded RO membranes are replaced with virgin ones and disposed of in landfills. Therefore, reduction of the membrane replacement costs and the environmental impact have become issues. To address these issues, Mitsubishi Heavy Industries, Ltd. (MHI) has developed a chemical agent (desalination performance rejuvenation agent) that selectively repairs degraded areas of cellulose acetate RO membranes and rejuvenates the desalination performance, thereby reducing the frequency of membrane replacement (prolonging the membrane life). This report introduces the characteristics and effects of the chemical agent for rejuvenating desalination performance of cellulose acetate RO membranes.
