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Reverse osmosis systems have taken at-home water filtration to the next level.
Touted as one of the very best methods available, you may be asking, is it really that good? What does an RO membrane actually remove? And what doesn’t it remove?
Let’s find out!
A reverse osmosis membrane can remove pesticides, dirt, asbestos, sediment, bacteria, cysts, and viruses from your water supply; plus:
So, what does an RO membrane remove from water?
A reverse osmosis membrane removes harmful pesticides, dirt, sediment, asbestos, volatile organic compounds, microorganisms such as bacteria and viruses, proteins, and more. It can also remove up to about:
And that is only the reverse osmosis membrane itself! Meaning, RO systems that come with additional pre and post-filtration stages, as they usually do for home use, will remove even more contaminants.
Reverse osmosis membrane pores are so tiny, that they will inadvertently remove most viruses and bacteria from water. However, this is not the purpose they were designed for, and the bacteria may proliferate on the RO membrane and in the pre-filters. Most systems will be labeled to be used with “biologically-safe” water.
If you have water that is highly likely to be biologically contaminated, then you may need to look at additional filtration steps such as UV purification or chlorination.
An RO membrane removes contaminates from the water that are too large to fit through its pores. The pores on the membrane are so small that this covers a wide range of things, but not everything.
This is why the pre-filtration in an RO system is essential.
Reverse osmosis is primarily a mechanical filtration method, which means that impurities are rejected based on size exclusion. Here is how it works:
Pressure is utilized to push contaminated water through a semipermeable membrane.
This membrane has tiny pores that are big enough to allow the very small water molecules to diffuse through, but not most contaminants with larger structures, and those are blocked from following the H2O past the membrane.
Instead, that wastewater is sent through a separate tube/line and down a drain.
With any water filtration setup, there are pros and cons to consider before deciding if it is right for you. In the case of reverse osmosis, you can expect the following:
If you have any questions about what an RO membrane removes from water please don’t hesitate to leave a comment below!
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