The reverse osmosis membrane has a pore size of 0.001 microns, which is smaller than even microbes such as bacteria and viruses. A reverse osmosis system does remove bacteria, as long as the membrane is in excellent condition.

As one of the most popular and commonly used water treatment systems, users and prospective buyers often wonder how effective reverse osmosis systems are in removing bacteria and viruses from their water supply.

How Does Reverse Osmosis Systems Remove Bacteria?

The reverse osmosis system incorporates multiple filtration stages for the water treatment process. As tap water passes through the different filters in this water system, only water molecules come out as pure water. The different filters include the sediment filter, the carbon filter, the RO membrane, and a post-filter.

Anyone with a rudimentary knowledge of water filtration will know that an average water filter cannot remove bacteria and other microbes from your water. This is because most filters on the market have a pore size that ranges from 1 micron to 5 microns.

Bacteria and viruses are smaller than this pore size, allowing them to pass through the filtration media alongside your drinking water. So, with normal filtration, you will get rid of contaminants such as heavy metal ions, but you’ll still have bacteria present in your filtered water.

When it comes to the reverse osmosis system, your tap water goes through the initial stages of filtration. Then it will go through the semi-permeable membrane. This membrane is the core of reverse osmosis technology and makes the RO system different from other filter systems. The RO membrane has an extremely tiny surface size (0.001 microns), enabling it to remove bacteria and viruses from passing along with your tap water.

However, the reverse osmosis process cannot kill bacteria and viruses; it just flushes them out. Only the UV filter can kill or sterilize microorganisms in water.

How Much Bacteria Can RO Systems Filter Out?

The RO system is highly effective in getting rid of bacteria and other microbes from your tap water. The RO system can filter out up to 99.9% of bacteria, including Campylobacter, E.Coli, Shigella, Salmonella, etc.

What Else Can RO Technology Remove From Water?

Aside from bacteria, viruses, and other organic matter affecting water quality, RO can remove contaminants present in the water. They include chemicals such as chlorine and heavy metals. RO filtration is the best possible solution to removing common contaminants from your water. RO also takes out minerals such as calcium, radium, potassium, etc.

Reverse Osmosis and UV Filtration

One must be mindful of the kind of reverse osmosis unit he gets for water treatment. This is because bacteria tend to reproduce rapidly in standard RO tanks. So if you have this kind of RO unit, getting another model may cost you more than you may like to spend. So the better and more affordable solution is to get a UV filtration system to combine with your RO unit.

We recommend purchasing a UV system and installing it before your RO unit because it’s the only treatment system that can kill living organisms in the water. There is no chance of bacteria reproduction in your storage tank.

UV filtration is the best when it comes to germicidal sterilization. The UV light in the water unit can emit strong UV rays that can kill any germs or microbes exposed to it. Once they absorb the light, their DNA and the proteins in their cells are sterilized. This renders them sterile and unable to reproduce. Eventually, they die off without reproducing, which makes them unable to cause diseases in your household.

However, unlike RO, UV filtration is limited to the sterilization or removal of microbes from your water. They are not designed to get rid of other contaminants.

We recommend you install a UV unit before the RO unit so that when the bacteria in your water are taken care of, the RO unit can handle the rest. Then, you get entirely pure and contaminant-free water coming to your home at the end of the entire process.

About the Author

Lucas Greer

Lucas vs. Wild - Lucas is a true nature lover and survivalist. When he's not teaching science at school, he can be found in nature, hiking, climbing, camping, and rafting. He knows all the tricks and DIYs for making unclean water drinkable with simple means in an emergency. At school, his students love him for his exciting water filtration projects.

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