Reverse Osmosis Contaminant Rejection - Water Quality Association
Drinking Water Contaminants and Their Control with Reverse Osmosis Water Treatment
Nominal Rejection Performance for Reverse Osmosis Membranes at 60 psi Net Pressure and 77° F.1
| TFC* type membrane Rejection | ||
Sodium Bacteria Organic Organic | 90-95% > 99% > 99%
> 99%
0-99% | 1. This table of nominal rejection performance is for reverse osmosis membranes used in drinking water systems operating at a net pressure (feed pressure less back pressure and osmotic pressure) of 60 psi and 77° F water temperature. The actual performance of systems incorporating these membranes may be different due to changes in feed pressure, temperature, water chemistry. contaminant level, net pressure on the membrane, and individual membrane efficiency. Countertop RO drinking water systems produce better overall rejection performance than under-counter systems due to maximizing of net pressure on the membrane. 2. While iron and manganese are effectively removed by the membrane, they also can easily foul its surface with deposits even at low concentrations. Generally, iron and manganese should be removed by other water treatment methods prior to RO treatment. 3. Nitrate removal depends on factors such as pH, temperature, net pressure across the membrane. and other contaminants present. |
*TFC-Thin Film Composite Membrane
This information is extracted from the Water Quality Association WQA.
