We've talked about her many times, but now it's finally her turn: REVERSE OSMOSIS! Thanks to the contribution to osmotic pressure, we are already familiar with the principle of osmosis, briefly summarized here: If a solution with different concentrations is separated from a semipermeable membrane, the water molecules will diffuse through the membrane to the concentrated solution on both sides until a concentration adjustment is achieved on both sides. REVERSE OSMOSIS is now based on a (surprise! 😊) Reversal of the osmotic principle: Here, the water molecules do not diffuse from the lower concentrated side to the more concentrated side, but from the more concentrated side to the side with the lower concentration. They do this because a pressure is exerted on the area with the more concentrated solution that is even greater than the osmotic pressure. In water treatment, this desalination process, which is also known as reverse osmosis, is often used because it is particularly energy-saving and environmentally friendly; in contrast to regeneration, no chemical additives are required here.