Reverse Osmosis Rejection Percentages
Typical Rejection Percentages of
Thin Film Composite (TFC) Reverse Osmosis Membranes
Below are the typical rejection (removal) percentages of a standard thin film (TFC) reverse osmosis membrane. These are averages based on experience and are generally accepted within the industry. They are not a guarantee of performance. Actual rejection can vary according to the chemistry of the water, temperature, pressure, pH and other factors. Not all contaminates reduced by reverse osmosis are reflected below.
Estimated Reverse Osmosis Rejection Percentages
The reverse osmosis process uses a semi-permeable membrane to reject a wide variety of impurities. Here is a partial list.
| Aluminum | 97-98% | Nickel | 97-99% |
| Ammonium | 85-95% | Nitrate | 93-96% |
| Arsenic | 94-96% | Phosphate | 99+% |
| Bacteria | 99+% | Polyphosphate | 98-99% |
| Bicarbonate | 95-96% | Potassium | 92% |
| Boron | 50-70% | Pyrogen | 99+% |
| Bromide | 93-96% | Radioactivity | 95-98% |
| Cadmium | 96-98% | Radium | 97% |
| Calcium | 96-98% | Selenium | 97% |
| Chloride | 94-95% | Silica | 85-90% |
| Chromate | 90-98% | Silicate | 95-97% |
| Chromium | 96-98% | Silver | 95-97% |
| Copper | 97-99% | Sodium | 92-98% |
| Cyanide | 90-95% | Sulphate | 99+% |
| Ferrocyanide | 98-99% | Sulphite | 96-98% |
| Fluoride | 94-96% | Zinc | 98-99% |
| Iron | 98-99% | ||
| Lead | 96-98% | Insecticides | 97% |
| Magnesium | 96-98% | Detergents | 97% |
| Manganese | 96-98% | Herbicides | 97% |
| Mercury | 96-98% | Virus | 99+% |
| TDS (Total Dissolved Solids) | 95-99% | Hardness | 93-97% |