Reverse osmosis membrane is an important component of water treatment equipment, widely used in fields such as electronics, electricity, automobiles, food, and medical care. All mechanical equipment has a service life, and the service life of water treatment equipment is not only related to factors such as design and material, but also to the service life of reverse osmosis membranes. Here, New Horizon Water Treatment shares with you methods and techniques for maintaining reverse osmosis membranes and extending the service life of reverse osmosis water treatment equipment. After the trial operation of the reverse osmosis equipment, two methods were used to protect the membrane. Test run the equipment for two days (15-24h), and then maintain it with a 2% formaldehyde solution; Or after running for 2-6 hours, use a 1% NaHSO3 aqueous solution for maintenance (the air in the equipment pipeline should be drained to ensure that the equipment does not leak, and all inlet and outlet valves should be closed). Both methods can achieve satisfactory results.
There are residual gases running under high pressure in reverse osmosis equipment, which can cause damage to the membrane due to the formation of a gas hammer. There are often two situations: after the equipment is emptied, when it is restarted, the gas is not completely discharged and quickly pressurized. The remaining air should be exhausted under a pressure of 2-4 bar before gradually increasing the pressure for operation. When the joint between the pre-treatment equipment and the high-pressure pump is poorly sealed or leaks (especially when the microfilter and its subsequent pipelines leak), the microfilter may become clogged due to insufficient water supply for reverse osmosis pre-treatment. In areas with poor sealing, some air may be sucked in due to vacuum. The microfilter should be cleaned or replaced to ensure that the pipeline does not leak. Gradually increase the pressure during operation without any bubbles in the flowmeter. If bubbles are found during operation, gradually decrease the pressure and check the cause. Due to the higher concentration of inorganic salts on the concentrated water side of the membrane compared to the raw water, it is prone to scaling and fouling of the membrane. Rinse with pre treated water containing added chemical reagents. Water containing chemical reagents may cause membrane fouling during equipment shutdown. When preparing to shut down the reverse osmosis equipment, stop adding chemical reagents and gradually reduce the pressure to around 3 bar. Rinse with pre treated water for 10 minutes until the TDS of the concentrated water is very close to that of the raw water.
The common problems in the use of composite polyamide films are poor resistance to residual chlorine, improper addition of chlorine and other disinfectants during use, and insufficient attention to microbial prevention by users, which can easily lead to microbial contamination. At present, many water treatment equipment manufacturers produce pure water with excessive microorganisms, which is caused by inadequate disinfection and maintenance. The reverse osmosis equipment is not maintained with disinfectant; The entire pipeline and pre-treatment equipment were not disinfected after installation of the equipment; Intermittent operation without taking disinfection and maintenance measures; Not regularly disinfecting pre-treatment equipment and reverse osmosis equipment; Maintenance fluid failure or insufficient concentration. During the use of reverse osmosis equipment, in addition to normal performance degradation, the degradation of equipment performance caused by pollution is more severe. The usual pollution mainly includes chemical scale, organic matter and colloid pollution, microbial pollution, etc. The symptoms exhibited by different types of pollution are different Colloidal pollution: When colloidal pollution occurs, it is usually accompanied by the following two characteristics: the microfiltration in the pre-treatment is quickly clogged, especially the pressure difference increases rapidly, and the B and SDI values are usually above 2.5 Microbial contamination: When microbial contamination occurs, the total number of bacteria in the permeate and concentrated water of the reverse osmosis equipment is relatively high, and maintenance and disinfection are usually not carried out as required Calcium scale: can be judged based on the quality of raw water and design parameters.
