What does reverse osmosis not remove

Clover Dane

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What Does Reverse Osmosis Not Remove

Reverse osmosis considers the best type of water filter. It ensures the removal of impurities from water as well as produce great-tasting water. The reverse osmosis filter is the most effective way to remove numerous sorts of contaminants along with impurities. On the other hand, there are also many other contaminants and impurities that this process will not remove from the water.

Working of reverse osmosis

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The reverse osmosis performs at the level of the molecule. This indicates that it has a filter membrane. This filter membrane only allows the passing of water molecules. Generally, it produces clean and pure water in the end. On the negative side, this process is not the full proof solution of filtered water that is completely free from all contaminants.

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Reverse osmosis not remove

There are many contaminants that are small than molecules and that is why they pass through the filter membrane of reverse osmosis. This process fails to remove very tiny and smaller contaminants. In short, we cannot say that the filtered water by reverse osmosis is completely free from contaminants and impurities. Some of the contaminants that this process will not remove are the following:

What Does Reverse Osmosis Not Remove
  • There are many products for the treatment of agriculture including fungicides
  • The dissolved gasses such as sulfide
  • Different kinds of organic compounds

The reverse osmosis does not remove the above-mentioned contaminants from the water. Now, I will tell some of the other harmful contaminants in detail:


The size of the pesticides is normally smaller. Due to their small size, the pesticides can easily move through the small pores of the membranes of the reverse osmosis system. Pesticides are harmful chemicals and especially very toxic when they present in the drinking water.

The water with pesticides is specifically not bad for any other things like when there is the requirement of water in any electronic device. But it will harmful to health and reverse osmosis does not exclude pesticides.


Likewise pesticides, the herbicides are also small in size. The herbicides can easily pass through the filter membrane of reverse osmosis. The water with herbicides is harmful to plants. Even such water also considers as the most harmful to humans. This water is dangerous for plants and the human body but does not affect any other products for example electronics.  


Overall, the reverse osmosis enables to eliminate a large quantity of chlorine from water. However, a tiny quantity of chlorine resides in the water. Especially, if the membranes of the reverse osmosis are old, then chlorine will remain in the water. 

In this case, the system will not able to remove the complete amount of chlorine from water. Particularly, the quantity of chlorine is small in water and so then, this effect of water is insignificant.

At last

Reverse osmosis is great to remove many contaminants. But this system also not removes some other contaminants and impurities. Pesticides, herbicides, and chlorine are some major contaminants that this system cannot remove.