Nominal Rejection Performance of Standard TFC Reverse Osmosis Membranes
Nominal rejection performance table below is extracted from Water Quality Association knowledge base for standard thin film composite reverse osmosis membranes operating at operating at a net pressure (feed pressure less back pressure and osmotic pressure) of 60 psi and 77°F water temperature. Performance of ro systems utilizing TFC membranes may be less due to changes in feed pressure, temperature, water chemistry, contaminant level, net pressure on membrane, and individual membrane efficiency. Tank-less RO systems (such as countertop ROs) and ROs with atmospheric tanks produce better overall rejection performance than undersink ROs (or ROs with pressure tanks) due to maximizing of net pressure on membrane.
| Sodium | 90-95% |
| Aluminum | 93-98% |
| Magnesium | 93-98% |
| Potassium | 90-95% |
| Iron | 93-98% |
| Manganese | 93-98% |
| Calcium | 93-98% |
| Copper | 94-99% |
| Silver | 93-98% |
| Zinc | 93-98% |
| Strontium | 93-98% |
| Cadmium | 93-98% |
| Nickel | 93-98% |
| Mercury | 93-98% |
| Radioactivity | 93-98% |
| Chromium-6 | 94-99% |
| Chromium-3 | 94-99% |
| Lead | 94-99% |
| Chloride | 90-95% |
| Bicarbonate | 90-95% |
| Nitrate | 85-90% |
| Fluoride | 90-97% |
| Phosphate | 93-98% |
| Chromate | 90-95% |
| Cyanide | 90-95% |
| Sulfate | 93-98% |
| Boron | 55-60% |
| Arsenic + 3 | 70-80% |
| Arsenic + 5 | 94-99% |
| Selenium | 93-98% |
| Barium | 93-98% |
| Sediment | > 99% |
| Protozoa | > 99% |
| Ameobic Cysts | > 99% |
| Turbidity | > 99% |
| Asbestos | > 99% |
| Bacteria | > 99% |
| Giardia | > 99% |
* Source: water quality association, www.wqa.org
** 60 psi net pressure and 77° F water temperature
*** Performance depends on condition of feed water
