Reverse osmosis (in a small nutshell) basically means the purification of water by pushing same through a filtering process whereby undesirable elements in the water are removed and discarded.
I'm thinking that your question may relate to the "desalination" process by reverse osmosis which in essence is the removal of salt from sea water for drinking purposes. This is where a "high pressure" pump is needed to push water through the membrane even as the membrane would reject the passage of salt through it. So without the high pressure pump the salt water would have a hard time passing through the membrane filter. |