Main factors affecting the desalination rate and normal operation of reverse osmosis pure water systems

Components of a Reverse Osmosis Pure Water System

Pre-treatment system, reverse osmosis unit, post-treatment system, cleaning system, and electrical control system, etc.

1. The pretreatment system generally includes raw water pump, dosing device, quartz sand filter, resin softener, activated carbon filter, ultrafiltration device, precision filter, etc. Ultrafiltration technology, namely bipolar reverse osmosis pure water treatment technology, is applied in the reverse osmosis system.

2. The reverse osmosis unit mainly includes multi-stage high-pressure pumps, reverse osmosis membrane elements, membrane shells, and brackets. Its main function is to remove impurities from the water to meet the requirements of use.

3. The post-treatment system is an additional configuration when reverse osmosis cannot meet the water output requirements. It mainly includes one or more devices such as anion bed, cation bed, mixed bed, sterilization, ultrafiltration, and EDI. The post-treatment system can further improve the water quality of reverse osmosis to meet the requirements of use.

4. The cleaning system mainly consists of a cleaning water tank, a cleaning water pump, and a precision filter. When the reverse osmosis system is polluted and the water output index cannot meet the requirements, the reverse osmosis needs to be cleaned to restore its effectiveness.

5. The electrical control system is used to control the normal operation of the entire reverse osmosis system. It includes instrument panels, control panels, various electrical protections, and electrical control cabinets.

Main factors affecting the desalination rate and normal operation of the reverse osmosis pure water system:

1. Ion valence: The desalination rate increases with the increase of ion valence; the desalination rate of divalent and trivalent salts is higher than that of monovalent salts;

2. Molecular size: The desalination rate increases with the increase of molecular diameter;

3. Raw water temperature: When the raw water temperature increases, the desalination rate increases due to the decrease in water viscosity;

4. Raw water concentration: When the raw water concentration increases, the desalination rate decreases;

5. Operating pressure: When the operating pressure increases, the desalination rate increases slightly but not significantly;

6. PH value: Although the membrane is not easily blocked under acidic conditions, the desalination rate will decrease;

7. Dissolved gases: Soluble gases in the free state are easily permeated without being removed, such as CO2, SO2, O2, Cl2, H2S, etc.;

8. Hydrogen bond tendency: For compounds containing strong hydrogen bonds, the removal rate is very low, such as water, phenol, and ammonia, etc.; (This is why the removal of impurities and dissolved substances in water is achieved to achieve the purpose of separating water from other substances);

9. Organic matter: Organic matter in water has a polluting effect on the membrane, and the more organic matter, the easier the membrane performance deteriorates;

10. Water hardness: The higher the water hardness, the easier the membrane is to block. For high-hardness water, it should be softened first to reduce the hardness before reverse osmosis;

11. Solid particles: Solid particles are extremely harmful to reverse osmosis membranes and must be pre-treated;

12. Microorganisms: Microorganisms and bacteria in water are harmful to the membrane and must be pre-treated (our company uses ultrafiltration membranes for treatment, which is at the advanced level in China);

13. Oxides: Metal oxides entering reverse osmosis cannot be removed automatically and should be removed regularly with chemical drugs.