How does an RO membrane work?Reverse osmosis water filtration systems work
by using high pressure to force water through a semipermeable reverse osmosis membrane element
. RO membranes
are made of a thick polyamide film that contains tiny pores through which water can flow. RO membrane element pore sizes can vary from 0.1 to 5,000 nanometers (nm) depending on application. The pores in the RO membrane are small enough to restrict organic compounds such as minerals and salt, but allow water molecules to pass through. Reverse osmosis membranes
are also porous and restrictive enough to filter out disease causing pathogens and bacteria from water.
About RO membrane life expectancyTypically RO membranes have an estimated life expectancy of about 2 years. There are many variables that come into play in determining a RO membrane’s life expectancy, such as feed water quality and amount of use. There are methods for cleaning a reverse osmosis membrane but often are not cost effective for residential RO systems.
About RO membrane foulingAll reverse osmosis membranes lose their performance and will foul over time. One of the primary reasons for RO membrane fouling is because of substances that deposit on the reverse osmosis membrane surface. The RO membrane elements can become fouled by suspended solids, microorganisms, and build-up from mineral scale. Examples of suspended solids often found in feed water can include oil, silica, clay, iron, sulfur and acids. To increase the life of your RO membrane, reduce most of these suspended solids before the water enters the membrane. Use a 5 micron carbon prefilter cartridge before the reverse osmosis membrane. This will help, but may not completely remove all suspended solids that cause a RO membrane to foul.