How does Reverse Osmosis work?

Reverse Osmosis uses a membrane that is semi-permeable, allowing water to pass through it, while rejecting the contaminants that are too large to pass through the tiny pores in the membrane. In Reverse Osmosis, water is forced against a membrane that is semi-permeable, allowing water to pass through it, while rejecting the contaminants that are too large to pass through the tiny pores in the membrane. Impurities are left behind and are rinsed away to a waste drain.