Water purification by RO method
What is reverse osmosis?
Water purification by RO method or Reverse osmosis is one of the best methods for removing dissolved ions from water. Since only water molecules are able to pass through the pores of the semipermeable membrane, as a result, almost all dissolved ions and molecules (including salt, sugar, and solutes in water) remain behind the membrane and are removed from the water. .
What is natural osmosis?
Natural osmosis occurs when two solutions of different concentrations are separated by a semipermeable membrane. The osmotic pressure directs the pure water through the pores of the membrane into a more concentrated solution and this process continues until the concentration of both solutions is equal.
What is the difference between natural osmosis and reverse osmosis?
The process of migration of salty water to water with higher salinity in nature is called osmosis. This process is observed in all humans as well as the absorption of water from the soil by the roots of plants. Man for RO water purification Nature is inspired by this behavior and uses its opposite to remove salt, ions, salts and pollutants in water with the help of industrial desalination. In this method, a semi-permeable membrane is used and water with a higher concentration that contains pollutants is passed through it by pressure. The passage of water with many pollutants through the semi-permeable membrane causes only water molecules to pass through the membrane and the solutes and pollutants remain on the other side of the membrane. Considering that in Water purification by RO method, water with higher concentration moves towards water with lower concentration and it is the opposite of nature’s behavior, so it is necessary to use pressure pumps for this purpose.
Important steps in RO water purification
A semi-permeable membrane is a filter that prevents the passage of some ions and atoms by having a surface with very small holes. The use of this membrane in reverse osmosis (Reverse Osmosis) greatly reduces pollutants, and on the other hand, excessive accumulation of waste materials on it will lead to a decrease in filter performance. For this purpose, several steps in RO water purification is considered to overcome these limitations.
Among the most important steps in water purification by RO method, the following can be mentioned:
Water pre-treatment
As mentioned, the semi-permeable membrane faces a decrease in performance over time due to the accumulation of various pollutants on it. For this purpose, it is necessary to first remove some of the pollutants in the water by different methods as a pre-treatment, and then the water with less turbidity enters the reverse osmosis device. Among the processes carried out in the pre-treatment stage, we can mention the removal of suspended solids in water. In addition, with the help of disinfectants such as chlorine, the microorganisms in the water are removed to a large extent, and the pH is adjusted and the sedimentation substances are removed. By carrying out these processes, the health of the membrane can be helped to a great extent, and the water is more ready for reverse osmosis treatment.
The last stage of water purification is by RO method
After pre-purification, the water enters the reverse osmosis device and in order for them to pass through the membrane or membranes, pressure is needed, which is provided by special pumps for this pressure. The pores on the membrane are very small and only pure water will be able to pass through it and finally exit the device.
Advantages of water purified by reverse osmosis
Producing lead-free water and helping to reduce diseases such as blood pressure and anemia in children
Removal of parasites and microorganisms in water
Removing sodium in water and reducing liver and kidney diseases
