Reverse osmosis membranes (ro membranes) are semipermeable mechanisms that separate your tap water into two parts – the solute (contaminants) on the one side and the solvent (clean, healthy water ) on the other.
Ideally, ro membranes should be resistant to scaling, bacteria, chlorine and other contaminants. As you are about to find out, all membranes are not created equal; their performances vary.
There are three main types of reverse osmosis membranes contained within a filter cartridge; cellulose, aromatic polyamide and thin film composite membranes.
Of the cellulose membranes, you have the cellulose acetate and cellulose triacetate varieties.
On the plus side, these types of membranes are relatively inexpensive; not easily degraded by chlorine and other oxidants; and highly permeable to water.
However, they are susceptible to bacteria and start rotting at temperatures over 35�C. The rate at which cellulose membranes filter inorganic contaminants is also poor. This rate worsens over time as the layers within the membranes thicken and merge with use.
Cellulose membranes can only handle water with a limited pH range which means that water with a high pH balance also reduce their effectiveness.
Cellulose triacetate membranes filter contaminants like bacteria and salt more effectively than cellulose acetate membranes. Furthermore, they are not as susceptible to the pH balance of your tap water as cellulose acetate membranes.
It is critical to note that reverse osmosis water filters with cellulose membranes may contain dioxane; a chemical that under California’s proposition 65, is listed as a cause of cancer.
Laws of the state require manufacturers to place warning labels on products using this chemical. Unfortunately, manufacturers don’t know how much water is needed to flush out dioxane from a filter.
Aromatic Polyamide Membranes:
They are more expensive that cellulose membranes and are more susceptible to degradation by chlorine.
On the plus side, they are more effective at filtering organics than cellulosic membranes and are also less susceptible to bacterial attack.
They are also capable of handling water with a wider pH range and can withstand higher temperatures then cellulosic membranes. However, at extreme temperatures and pH range, they are still susceptible to degradation.
Thin Film Composites:
Of all the membrane types, thin film composites (TFC) filter the highest amounts of organic contaminants.
They are capable of handling water with a wide pH range and very resistant to rotting. The layers within these membranes are less susceptible to thickening than the other types of membranes.
On the downside, TFC reverse osmosis membranes cost the most of all the membrane types and have a low oxidant tolerance.
>>>>>>> Highly Recommended <<<<<<<