Whether you are seeking to filter out contaminants in industrial fluid or purify water for drinking, reverse osmosis is an effective way to get the job done. The process can remove impurities a fraction of a micron in size by using pressure and specially designed membranes.
Osmosis naturally occurs when fluids of different concentration are separated by a semipermeable membrane. The pores in the membrane allow the fluid to move through, leaving behind impurities.
With natural osmosis, fluid with fewer impurities will move through the membrane to join the fluid with more concentrated impurities. This is due to a difference in potential energy. Fluids with more impurities have less energy while pure fluids have high energy. The process occurs to even out the pressure in the fluids, also known as osmotic pressure.
To achieve proper filtration, impure fluids must pass through the membrane, not the other way around. This is done by manipulating the natural osmosis process. Pressure is applied to the fluid with impurities, thus increasing its potential energy. This process will make the concentrated fluid move through the membrane to join the purer fluid, filtering it in the process.
Different levels of filtration can be achieved by manipulating the amount of pressure exerted onto the fluid. Different membranes can also be used to allow some impurities to pass through while stopping others.