Reverse Osmosis vs. Nanofiltration

Reverse Osmosis (RO) and Nanofiltration (Nano) are two very similar technologies using essentially the same technology to remove impurities from water or other liquids.  In both systems, Membranes are used to separate a liquid from contaminates.  Membranes are basically filters with tiny pores that allow water through while trapping contaminates.

Nanofiltration is a newer technology than reverse osmosis and was developed for drinking water applications as it was found that RO removed some of the minerals in water that are considered beneficial for human health.  Nanofiltration allows beneficial minerals to pass through the membrane with the water while blocking contaminants such as heavy metals, pesticides etc that are harmful to the body.

Key differences between nanofiltration include:

  • Nanofiltration wastes little or no water whereas reverse osmosis wastes up to 50% of the water which you’re filtering
  • Nanofiltration uses gravity or pressure from the mains water supply to filter water whereas reverse osmosis uses electricity
  • Reverse osmosis removes important minerals from water which need to be replenished after filtration wheras nanofiltration does not require replenishment of minerals