Thanks to reverse osmosis, you can drink water that is free of almost all pollutants.
In nature,osmosis is a physical phenomenon in which water spontaneously passes from a medium with a low concentration of solutes to a more concentrated medium. In our bodies, for example, water circulates to balance the concentration of salts and nutrients between our cells and our blood.
Reverse osmosis is the exact opposite of the natural phenomenon. High pressure is applied to polluted water to force it through a semi-permeable membrane. Result: only the water molecules (H₂O) pass through, the pollutants remain trapped.
Reverse osmosis works by playing on osmotic pressure and the diffusion of molecules through a very dense membrane. Even molecules much smaller than a bacterium are retained.
The membrane is not simply a "little sieve", it's a semi-permeable structure that favors the passage of certain molecules (H₂O), but blocks others depending on the size, polarity, and sometimes electrical charge of the molecules.
A conventional filter blocks out the big stuff. The reverse osmosis membrane is like an ultra-fine molecular barrier, sorting water at the molecular level. What is dissolved (such as PFAS, nitrates or drugs) passes through a conventional filter, but is retained by reverse osmosis.
