What is reverse osmosis?

Reverse osmosis is a process in which a solvent (usually water) is forced through a semi-permeable membrane that allows only certain molecules or ions to pass through while blocking others. This technique is widely used in water purification, desalination, and wastewater treatment, as it effectively removes contaminants, salts, and other impurities from the water.

In reverse osmosis, pressure is applied to overcome the natural osmotic pressure, thereby pushing the solvent from a region of higher concentration (contaminated water) to a region of lower concentration (purified water). The semi-permeable membrane allows water molecules to pass while rejecting larger molecules and ions, ensuring that the resulting permeate is clean and suitable for use.

This process is distinct from evaporation, which involves phase change of water from liquid to gas, and does not inherently provide the same level of filtration. Filtering large solids is also different, as it is not specifically about the molecular separation that occurs in reverse osmosis. Boiling water, while effective for disinfecting and purifying in some cases, does not involve a membrane or the principle of osmosis. Therefore, the correct understanding of reverse osmosis is crucial as it is a vital technology in modern water treatment systems.