Reverse osmosis technology, as the current mainstream membrane water treatment process, is widely used in various water treatment scenarios. However, in practical applications, reverse osmosis equipment often faces the problem of scaling, which not only affects the operational efficiency of the equipment, but also shortens its service life. So, why does reverse osmosis equipment scale? How should we respond?
Analysis of scaling reasons
When the raw water passes through the reverse osmosis membrane, some insoluble salts will precipitate on the membrane layer, forming solid substances, namely scaling. During the operation of the reverse osmosis system, fresh water is generated due to low-pressure flushing, which gradually increases the concentration of water on both sides, especially the concentration of salt, providing conditions for scaling of precipitable substances in the salt.
Response strategy
1. Optimize system design: During design, the replacement efficiency of the concentrated water layer should be ensured, while minimizing the salt content in the concentrated water as much as possible. For specific insoluble salts such as barium sulfate and strontium sulfate, special attention needs to be paid in the design of RO systems.
2. Control water quality: For natural water sources, attention should be paid to the insoluble salt components, such as calcium carbonate, calcium sulfate, etc. Meanwhile, due to human factors, the concentration of certain inorganic salts such as phosphate, iron, aluminum, etc. may increase, which needs to be considered when adding chemicals to the system.
3. Agent selection: When adding agents, it is necessary to ensure compatibility between various agents to avoid interactions between different agents that may cause insoluble substances to precipitate and contaminate membrane components.
4. Pre treatment: In order to better protect the reverse osmosis equipment, the raw water can be pre treated, such as using activated carbon or quartz sand filtration to remove large particle impurities, and then using ion exchange resin softening to remove calcium and magnesium ions from the water, thereby reducing the possibility of scaling.
5. Operation and maintenance: During operation, appropriate filtration rate and backwash time should be ensured to ensure the good operation of the filter. At the same time, the water flow should be uniform to ensure the filtering effect.
In summary, through reasonable system design, water quality control, reagent selection, pretreatment, and daily operation and maintenance, scaling in reverse osmosis equipment can be effectively reduced, thereby extending the service life of the equipment and improving water treatment efficiency.