What type of pressure is required in reverse osmosis to push water through the membrane?

To effectively push water through the membrane in reverse osmosis, high pressure is required. This process involves forcing water against its natural osmotic flow, which typically moves from areas of low solute concentration to areas with high solute concentration. In reverse osmosis, however, we aim to achieve the opposite effect—removing impurities from water.

The application of high pressure is essential because it creates a significant driving force that overcomes the osmotic pressure. The membrane used in reverse osmosis is semi-permeable, meaning it allows water to pass through while blocking larger particles and contaminants. This process not only separates the clean water from the impurities but does so efficiently, which is crucial for applications such as desalination and water purification.

Low pressure, no pressure, or just atmospheric pressure would not provide the necessary force to push water through the membrane, resulting in a much less effective or completely ineffective purification process. Hence, high pressure is fundamentally important for the success of reverse osmosis systems.