Reverse osmosis pure water equipment produces concentrated water while generating pure water. The main issue is that the concentrated water has high levels of calcium, magnesium, and other ions, resulting in high hardness, making it unsuitable for reuse as raw water in pure water systems. So, how should this concentrated water be treated? For most manufacturing enterprises, aside from the reverse osmosis concentrated water generated in the water production workshop, various other types of wastewater are also produced. For example, production wastewater discharged from the manufacturing workshop and domestic wastewater from the factory premises. Treating each type of wastewater separately is often not economical. Therefore, most companies choose to segregate some special types of wastewater and mix the various wastewaters together for collective treatment. The water quality of reverse osmosis concentrated water is characterized by high hardness and high salt content, while key pollution indicators such as turbidity and COD are very low. Mixing reverse osmosis concentrated water with other wastewaters can serve to dilute and regulate, thereby reducing the pollution load of the influent in the mixed wastewater treatment system. Some enterprises produce wastewater containing large amounts of alkaline substances like sodium carbonate, which can react with calcium and magnesium in the reverse osmosis concentrated water to form precipitates such as hydroxides or carbonates, thereby reducing water hardness. For instance, an aluminum company modified its treatment system for the concentrated water from its reverse osmosis system by mixing it with waste alkaline water from the production process. After removing calcium and magnesium hardness, the treated water is reused in production, reducing the cost of production water. Pure water resistivity refers to the resistance between two opposite sides of a 1 cm3 cube of water at a specific temperature, measured in Ω*CM. It is generally a parameter used to indicate the quality of high-purity water. Pure water treatment technology is a method of producing pure water that combines ion exchange technology, ion exchange membrane technology, and ion electromigration technology.

During the use of reverse osmosis pure water equipment, certain factors may occasionally affect its operational status. Generally, aside from proper usage methods, one important factor is the inlet water pressure. Changes in water pressure can have a tangible impact on the operational status of reverse osmosis pure water equipment. Therefore, when using reverse osmosis equipment, it is essential to ensure that the inlet water pressure is maintained within a reasonable range. Multi-stage centrifugal high-pressure pumps are used to provide the operating pressure for the main unit of the reverse osmosis pure water equipment to meet desalination requirements. Typically, low-pressure reverse osmosis membranes require an inlet pressure of about 0.6-1.0 MPa, while high-pressure membranes require an inlet pressure of about 1.2-1.5 MPa. If the inlet water pressure of the reverse osmosis pure water equipment is too low, the desalination efficiency will significantly decrease, and the water production will fail to meet design requirements. Prolonged operation under low pressure can lead to membrane fouling, causing premature failure of the membrane elements.