What Do Reverse Osmosis Filters Remove?

Reverse osmosis filters are used in water systems to remove dissolved minerals and other pollutants. Reverse osmosis filters can also be used to remove salt from water. Read on to learn more about what RO filters can remove from water.

What Can RO Filters Remove?

RO filters can remove contaminants such as salts, metals, and organics. These types of contaminants often occur in water systems due to natural processes like erosion or runoff.

Wastewater treatment plants use RO filters to reduce the levels of salt and other minerals found in wastewater before it’s released into the environment. This process is known as desalination and can help municipalities meet Clean Water Act (CWA) standards for public drinking water.

RO filters are also used by beverage companies who want to remove salts and other minerals from water before bottling it for consumers. Because many people prefer the taste of bottled water over tap water, many companies will filter their tap water with an RO filter before bottling it.

Reverse osmosis filters can be used to treat a variety of different substances found in nature such as salt, metals, and organics. This makes them a valuable asset to any company that deals with sensitive materials like pharmaceuticals or chemicals. They’re also regularly used by beverage companies because they improve the taste and quality of bottled water.

How Reverse Osmosis Filters Work

Reverse osmosis filters work by pushing water under pressure through a semipermeable membrane. The membrane has microscopic pores that allow pure water to pass, but retains dissolved minerals and contaminants.

The pressure applied to the water forces it through the membrane and out of one side of the filter. This process removes up to 98 percent of dissolved solids such as salts, heavy metals, and chemicals from the water stream.

How does reverse osmosis work?

Can Salt Can Be Removed From Water With RO Filters?

Removing salt from water is one of the most common uses of RO filters.

Salt is a natural mineral that, when dissolved in water, can contaminate the water and its taste. Salt can also cause damage to pipes and plumbing systems.

Reverse osmosis filters work by removing dissolved solids from the water. The solids are left behind while clean water passes through the membrane and out of the filter.

An advantage of RO filters is that they remove about 98 percent of salt from water while leaving all other minerals intact. This means you can get pure, drinkable water without any unpleasant taste or aftertaste.

How Ro Filters Remove Dissolved Minerals

Reverse osmosis filters are typically used in commercial and municipal water systems to remove dissolved minerals and other pollutants from the water.

The RO filter is a membrane that removes minerals, salts, bacteria, and other impurities that may be in tap water. The membranes use a technique called reverse osmosis to force the process of separating the dissolved particles from the clean water.

Even though the contaminants have been removed from the water, they are not removed from the membrane. As a result, RO membranes require regular maintenance or replacement through a bi-weekly cleaning process. It’s also important to replace RO membranes yearly for maximum efficiency of filtering out particles from your drinking water.

What Contaminants Does Reverse Osmosis Remove?

The membrane in reverse osmosis filters allows water to pass through the filter, while the pollutants are left behind. This process removes salt and sediment from water, as well as some chemicals that might be found in the water.

Salt and sediment can cause corrosion and give water a bad taste. Reverse osmosis can remove up to 98 percent of these impurities.

What Is Not Removed by Reverse Osmosis?

Reverse osmosis filters are used in water systems to remove dissolved minerals and other pollutants. Reverse osmosis filters can also be used to remove salt from water. Generally, reverse osmosis filters can remove most chemicals, bacteria, viruses, parasites, nitrates, radionuclides and pyrogens.

Often times the remaining pollutants that are not removed by reverse osmosis are minerals. If you have a very high mineral content in your water, then the only way to remove those is by using a distillation method.

Does Reverse Osmosis Filter Out Viruses?

No. One concern with using RO filters is that they don’t remove viruses. Reverse osmosis filters do not remove bacteria, parasites, fungi, or viruses from the water.

Some sources will say that reverse osmosis filters remove 99% of the chlorine in the water and lower levels in other contaminants like lead and arsenic. However, in order to get rid of viruses for good, you’ll need a different type of filter to handle them.

That’s why we recommend adding an activated carbon filter, which can also reduce odors and tastes in the water. To learn more about activated carbon filters or how they work, click here.

Can Bacteria Grow in Reverse Osmosis Water?

The answer is yes and no. Theoretically, bacteria can grow in RO water because any living organism requires some source of nutrition to grow and survive. But, the growth of bacteria in RO water is highly unlikely and nearly impossible under normal conditions.

The reason for this is that the RO membrane separates salts from water molecules. In other words, the RO membrane filters out salt ions from water molecules. And since salt ions are one of the main sources of food for bacteria, it removes one of the major food sources for bacteria to grow and multiply.

This means that your tap water should be safe to drink even if it has been through an RO filtering process because most of the harmful elements have been filtered out before being supplied to you.

However, there are other factors to consider.

For instance, if the RO membrane is not cleaned and maintained regularly, harmful elements like lead may build up on the membrane over time. This will allow harmful elements like lead to mix with your drinking water supply and make it unsafe to drink.

But this is pretty rare because most people who use RO water filters maintain their RO systems regularly.

There is also another factor to consider. 

RO water filters are not 100% efficient in removing all harmful elements from your water supply. This means that there’s a very small chance that some harmful elements may still be present in your drinking water supply even after it has gone through an RO system. 

The good news is that these harmful elements are present in such small amounts that it doesn’t pose any health risks to you, at least not for the average person.

How Much Does a Reverse Osmosis Unit Remove?

Reverse osmosis water filters are designed to remove minerals, bacteria, and other impurities from drinking water. The amount of contaminants removed by RO units depends on the type of water being filtered, the size of the filter, and the level of filtration.

If you have a lot of dissolved solids in your water supply, an RO unit will only be able to remove about 95% of those solids. If you’re filtering extremely dirty or polluted water that contains plenty of particulates or sediment, your reverse osmosis filter can remove upwards of 99% of those particles.

A reverse osmosis filter won’t be able to remove 100% of all impurities if you’re using it for brackish or seawater. Reverse osmosis filters use pressure to force water through a semi-permeable membrane (often made from cellulose) with small pores. The membranes reject any large particles found in the incoming water supply, but they can’t always reject smaller particles like salts and some types of bacteria that are present in that type of drinking water.


The reverse osmosis process is a simple procedure used to purify water by removing impurities through semipermeable membranes which allow only pure water molecules to pass through while rejecting contaminants. The process involves forcing mixtures of water and contaminants through a membrane using pressure (typically around 100 psi). This forces the impurities to pass through the membrane while leaving the water behind. The resulting water is free of salts, metals, and other impurities.

Reverse osmosis is a process that uses a high pressure pump to force water through a semipermeable membrane, allowing only pure water to pass through. The process removes or reduces dissolved solids in the original source water by osmosis, which is the diffusion of solvent (pure water) across a selectively permeable membrane separating two solutions of differing concentrations.

Meet the author: Jessica Chen

Jessica is a fishing enthusiast and yoga fanatic who enjoys traveling the world and reading books about Buddhism. She has a passion for writing, food, and wine. “Winter is my favorite season. I love sitting by the fire with a good book and a warm cup of hot chocolate.” Learn more about Jessica and the rest of the team.