Osmosis and reverse osmosis are physical phenomena. Water containing salt has a natural osmotic pressure. When the brine (raw water) and pure water are separated by a semi-permeable membrane with a micropore diameter of one ten thousandth of a micron, pure water Water will penetrate the semi-permeable membrane and enter the raw water side due to the osmotic pressure. On the contrary, if a pressure higher than its own osmotic pressure is applied to the raw water side, the molecules in the raw water will pass through the semi-permeable membrane and enter the pure water side, but the salt, fine impurities, organic matter and other components in the raw water cannot enter the pure water. On the water side, this is reverse osmosis. Based on this principle, people invented reverse osmosis membrane and reverse osmosis technology and applied them to water treatment.
Application of reverse osmosis technology Reverse osmosis technology can be used for brackish water desalination, drinking pure water production, high-quality drinking water production, industrial production water preparation with low salt content and low hardness, industrial pure water and high-purity water preparation, industrial wastewater recycling, etc.
The main features of reverse osmosis water treatment: physical method desalination, stable effluent water quality, continuous production, simple operation, low operating cost, low waste water discharge, small footprint, and wide applicable water quality range.
When pure water and brine are separated by an ideal semi-permeable membrane, the ideal semi-permeable membrane only allows water to pass through but prevents the passage of salt. At this time, the water on the pure water side of the membrane will spontaneously flow into the salt water side through the semi-permeable membrane. For osmosis, if pressure is applied to the brine side of the membrane, the spontaneous flow of water will be inhibited and slowed down. When the applied pressure reaches a certain value, the net flow of water through the membrane is equal to zero. This pressure is called osmotic pressure. When the pressure exerted on the brine side of the membrane is greater than the osmotic pressure, the flow of water will be reversed. At this time, the water in the brine will flow into the pure water side. The above phenomenon is the basic principle of water reverse osmosis (RO) treatment.
RO (Reverse Osmosis) reverse osmosis technology is a membrane separation filtration technology that uses pressure gauge differences as the power. Food, beverage, desalination and other fields.
RO reverse osmosis membrane has a pore size as small as nanometers (1 nanometer = 10-9 meters). Under a certain pressure, H2O molecules can pass through the RO membrane, while the source water contains inorganic salts, heavy metal ions, organic matter, colloids, bacteria, viruses, etc. Impurities cannot pass through the RO membrane, so that pure water that is permeable and concentrated water that is impermeable are strictly distinguished.
The conductivity of pure water filtered by RO membrane is 5 s/cm, which meets the third-level water standard of the national laboratory.