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This post was last edited by hesonchang214 on 2019-11-24 at 10:17. Reasons for the reduced service life of reverse osmosis membranes: 1. Improper operation of the reverse osmosis equipment leads to damage to the membrane’s performance. Residual gases in the reverse osmosis equipment can cause air hammer effects under high pressure, which damages the reverse osmosis membranes. Two situations usually occur: A. After the equipment is emptied and restarted, operation begins with pressure rising rapidly before all the gas has been expelled. The remaining air should be exhausted under a pressure of 2–4 bar before gradually increasing the pressure for operation. B. When the seal at the connection between the pretreatment equipment and the high-pressure pump is poor or there is leakage (especially leakage in the microfilter and the pipelines following it), and when the water supply for pretreatment is insufficient, if the microfilter becomes clogged, air will be drawn in at the poorly sealed areas due to vacuum. 2. Incorrect method of shutting down the reverse osmosis equipment. A. Rapid pressure reduction during shutdown did not result in thorough flushing. Since the concentration of inorganic salts on the concentrated side of the membrane is higher than that in the raw water, scaling occurs easily, leading to membrane contamination. B. Rinse with pretreated water to which chemical reagents have been added. Water containing chemical reagents may cause membrane fouling during equipment shutdown. 3. Inadequate disinfection and maintenance of reverse osmosis equipment leads to microbial contamination. This is a common problem in the use of composite polyamide membranes; since these membranes are not resistant to residual chlorine, disinfectants such as chlorine are not used properly during operation. Coupled with users’ insufficient attention to preventing microbial growth, this easily results in microbial contamination. Currently, the microbial levels in pure water produced by many manufacturers are above acceptable limits, which is caused by inadequate disinfection and maintenance. 4. Inadequate monitoring of residual chlorine in reverse osmosis systems. 1. The membrane can be damaged by residual chlorine if the pump used for adding chemicals fails, if the chemical solution loses its effectiveness, or when the activated carbon becomes saturated. 2. Damage to membrane performance caused by untimely cleaning and incorrect cleaning methods