Reverse osmosis (RO) is a highly effective filtration process based on osmosis, but driven in reverse by pressure.

Natural osmosis

Water diffuses through a semipermeable membrane from low to high solute concentration until equilibrium.

Reverse osmosis process

External pressure pushes water from the concentrated side through the membrane; contaminants stay behind.

Separation of contaminants

Salts, metals, organics and microbes are retained; mainly water passes.

Permeate

The result is high-purity permeate for drinking, cooking and industry.