Many people are curious as to why the reverse osmosis water purifier will discharge waste water. What is the difference between it and the physical filter water purifier? What is its filtration mechanism?
Why is it called 'reverse osmosis' filtering?
When the same volume of dilute solution (such as fresh water) and concentrated solution (such as salt water) are placed on both sides of the semipermeable membrane, the solvent in the dilute solution will naturally pass through the semipermeable membrane and spontaneously flow to the side of the concentrated solution. This phenomenon is called infiltration. When the permeation reaches equilibrium, the liquid level on the concentrated solution side will be higher than the liquid level of the dilute solution, that is, a pressure difference is formed, and the pressure difference is the osmotic pressure. When a pressure greater than the osmotic pressure is applied to the side, the flow direction of the solvent will be opposite to the original permeation direction, and the flow starts from the concentrated solution to the side of the dilute solution. This process is called reverse osmosis.
Simply put, by energizing, applying pressure to the concentrated solution, changing the original direction of penetration, realizing the countercurrent of the concentrated solution, thereby purifying the concentrated solution and producing pure water.
Why does it produce wastewater?
The core part of the pure water machine is actually a liquid concentration process during the working process. The salt content in the water increases with the flow of water through the surface of the reverse osmosis membrane, and the osmotic pressure of the water increases continuously. When the pressure is increased to the pressure of the booster pump, water cannot flow into the clean water end through the reverse osmosis membrane. The water that fails to pass this part is the wastewater generated when the water is produced.
'Wastewater' is really nothing?
First of all, in terms of the development of the current water purification technology, basically a cup of pure water will discharge a glass of wastewater in the same way. That is, if your family can drink 3L of water a day, then 3L of wastewater will be discharged on this day. I feel a lot when I hear it, but with our toilet, mopping, washing, and bowling, this water consumption is much smaller.
Moreover, the waste water is not nothing, but it has also been filtered by the first three levels of the water purifier. These waste water can be used to mop, flush the toilet, and wash things well.