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Does reverse osmosis remove bacteria from water? Explained

Does reverse osmosis remove bacteria


When buying a reverse osmosis filter, you extensively research reverse osmosis filtration, reverse osmosis membranes, reverse osmosis faucet, and a lot more to make a knowledgeable choice. But you are mostly looking for the answers to these crucial questions:

  1.  Does my reverse osmosis filter remove bacteria from water?
  2. What types of bacteria in my water, do reverse osmosis membranes remove?
  3. How does my reverse osmosis remove bacteria from water?
  4. Lastly, what is the best point to choose a reverse osmosis filter for my house?

If you are looking for objective answers to the questions mentioned above, you can lay back and chill because you have come to the right place. The following article will counter all your queries and doubts about reverse osmosis systems and bacterial elimination and deliberations for choosing a reverse osmosis filter.

Presence Of Bacteria In Drinking Water

Types Of Bacteria In Water

There are various types of bacteria found in water, depending on your water’s source. 

If the source of your water is groundwater, then there is a high possibility of finding the following bacterial organisms in your water:

types of bacteria in water
  • Escherichia Coli
  • Campylobacter jejuni
  • Giardia Lamblia
  • Salmonella
  • Legionella Pneumophilia
  • Cryptosporidium 

If the source of your water is surface water, lake, or reservoir, there is a possibility of finding the following bacteria in your water:

  • Cryptosporidium parvum
  • V. cholerae, 
  • V. parahaemolyticus and 
  • V. vulnificus
  • A. hydrophila

Effects Of Bacteria On Human Health

Bacterial organisms and microbial organisms are a risk to human health, certainly when ingested through drinking water. According to WHO, Cholera causes almost 21000 to 43000 deaths globally due to the lack of access to sanitize drinking water. Since most sources of water are groundwater sources, the following are the symptoms and effects of bacteria on human health:

  1.  E.coli: It causes nausea, vomiting, diarrhea, and abdominal pain if ingested or drank in contaminated water.
  2. Giardia Lamblia: It causes the infection giardiasis, which leads to diarrhea, nausea, cramps, and gas.
  3. Cryptosporidium: The main symptom of consuming this bacteria through water is painful and severe diarrhea.
  4. Salmonella: It also causes diarrhea, pains, chills, headache, and fever.
  5. Campylobacter Jejuni: It leads to cramping, diarrhea, pain, and fever.
  6. Legionella Pneumophilia: It causes the bacterial infection Legionnaires. It results in cough, muscle aches, fever, and shortness of breath.

Where Does Bacteria Come From In Drinking Water?

To eliminate bacterial contamination, you need to know where bacteria come from in the drinking water. One of the main sources of bacteria in drinking water is animal faeces, ill-designed wastewater systems, and leaking sewage systems. The other sources of bacteria could be runoff water from agricultural farms and stagnant water. 

How To Detect Bacteria In Drinking Water?

To detect bacteria in drinking water, you need more than a human eye. Bacterial organisms cannot be sensed by either of the three senses: sight, sense, or smell. One way to check whether your drinking water contains any bacterial growth or presence is to get the water tested. EPA (Environment Protection Agency) sets certain standards and procedures to ensure that the water reached to houses is safe and drinkable. The process through which the water is deemed safe is called the total coliform testing procedure. 

The total coliform test of any public water source must be reported to contain no traces of coliform bacteria. If the test is ‘total coliform positive,’ it should be further tested by performing a fecal conform test.

To detect bacteria in drinking water at home, you can find the closest water testing laboratory and send a sample vial of water to run tests upon it. You can send the sample through the mail, and you can then analyze the results to see whether your drinking water is safe or not.

How Does Reverse Osmosis Remove Bacteria From Water?

The Reverse Osmosis water filters that remove bacteria and other contaminants are available with the best quality countertop reverse osmosis systems and undersink RO systems. Before getting to the question ‘does reverse osmosis kill bacteria?’ it is essential to be aware of how does reverse osmosis filtration system removes bacteria from water. In a Reverse osmosis filtration and reverse osmosis water purification system, the contaminated water travels through multiple stages before reaching the purified state. For a basic reverse osmosis filtration system, the following steps are followed to remove bacteria from water:

  1. The water is passed through a reverse osmosis prefilter which filters out sediments and dirt. The prefilter can be a carbon filter or a sediment filter. This filtration ensures that the membranes reverse osmosis system uses to eliminate bacterias and pathogens is not damaged.
  2. The reverse osmosis membrane is the main part of the reverse osmosis filtration system. The semi-permeable membranes of reverse osmosis use removes all the contaminants larger than the water molecules, including bacteria and pathogens. The second step of reverse osmosis filtration and reverse osmosis water purification is crucial in removing bacteria from water.
  3. Now the filtered water makes its way to the reverse osmosis tank. The reverse osmosis tank acts as storage before the water goes through the reverse osmosis faucet.
  4. Before going to the reverse osmosis faucet, the water goes through a post-filter carbon filter. It removes foul taste and odor from the water.
  5. Lastly, the water is accessible from the RO tank through a reverse osmosis faucet.

For a countertop reverse osmosis filter, the steps of purification are the same as listed above but,

  1. Since it is a countertop reverse osmosis filter, there is no storage tank to store the purified water. The feed line of the filtered water can be directly attached to the revere osmosis faucet, so purified water is readily available.

Does Reverse Osmosis Remove All Bacteria?

Even with the membrane reverse osmosis system’s excellent efficiency, the membrane still leaves some impurities. These impurities have a molecular size smaller than a water molecule. For example:

  • Dissolved gases such as hydrogen peroxide
  • Pesticides
  • Herbicides
  • Chlorine
  • Agricultural fungicides

The answer in a simple manner to the question: does reverse osmosis remove all bacteria? Yes, it does. If the filter is maintained regularly, the RO filter efficiently removes all the bacterial contaminants from the water.

Benefits Of Reverse Osmosis Filters

One of the major benefits of reverse osmosis filters and reverse osmosis membranes is that it has such fine pores that it removes almost all the bacteria and contaminants from water. Other than this:

  • Good tasting water and food,
  • Removes almost all the dissolved solids from the water, making it crisp and fresh
  • The filters are easy and simple to maintain
  • The filters are inexpensive and efficient

Consider The Point To Choose Best Reverse Osmosis Water Filters

Removal Of Contaminants

One of the essential features of a reverse osmosis filter is its efficiency in removing contaminants and making the water suitable for use. Each RO filter’s efficiency is dependant on what it is used for daily.

For example, Frizzlife countertop RO system comes in two categories: a countertop reverse osmosis system, a portable reverse osmosis system, and an undersink RO system. Each of the filters is responsible for removing harmful inorganic and organic compounds. It is 99.99 percent efficient in removing fluoride, lead, arsenic, radium, asbestos.

A seawater reverse osmosis filter is required to eliminate sodium chloride from the water. This process is called reverse osmosis desalination. An efficient seawater reverse osmosis filter will effectively remove 99.99 percent of saline content from water to make it useable. 

Removal Of Bacteria

Other than contaminants, reverse osmosis membranes should be well-built to remove bacterias from the water. All reverse osmosis filters are designed with multi-layer membranes, which are suitable for removing almost all bacteria.

Filter’s Life & Replacement

The other important point to look at before selecting a RO system is the durability of the filters. Filter life can depend on multiple things, including flow rate, quality of water, and filtration use.

Frizzlife reverse osmosis systems replacement filters last up to 1 year or filter up to 1600 gallons of water.

A portable reverse osmosis system replacement filters must be changed once a year as they are not extensively used for heavy material filtration.

The longer the filter’s life and easier the replacement, the more durable the RO system.


Frizzlife reverse osmosis system has a productivity rate of 600 gallons of water per day. 

A portable reverse osmosis system is attached to your kitchen faucet or a reverse osmosis faucet. It can produce up to 120-220 gallons per day of purified water.

Seawater reverse osmosis systems can filter out 8,000 to 10,000 gallons per day for commercial use. Reverse osmosis desalination of seawater is used in agriculture and large-scale development programs.

UV Technology

While reverse osmosis is a good filter system, it should not be completely relied on to remove bacteria from water.  UV light kills bacterias by neutralizing their DNA so they cannot multiply in the water; UV light makes the bacteria harmless, whereas reverse osmosis filter removes it. 

Most RO filters do not come with a UV add-on, but you can buy UV disinfectants separately to make your drinking water safer.

Installation & Maintenance

According to the Frizzlife website, Frizzlife countertop filters do not require installation and can be plugged in. They are pricey but easy to maintain.

Seawater reverse osmosis filters are used both commercially and industrially. For commercial reverse osmosis desalination, seawater reverse osmosis filters come in parts, so they are easy to install. The components of the reverse osmosis desalination system need to be corrosion resistant to have increased durability. 

Portable reverse osmosis filters are compact and durable as they do not filter out a heap of water every day. Portable reverse osmosis systems do not require any installation as well. 


Some others question’s answers for our readers that might be helpful for reading.

Does reverse osmosis kill bacteria?

The most common misconception among filter buyers is that reverse osmosis kills bacteria. In Reverse osmosis water purification systems, reverse osmosis membranes filter out bacteria and push forward clean water, flushing the contaminants down the drain.

Does UV Technology Effects Bacteria?

The disinfectant method Ultra-Violet Germicidal irradiation is responsible for killing bacteria and other harmful microorganisms found in water or surfaces. UV lights kill bacteria completely rather than filtering it out.

What contaminants are not removed by the reverse osmosis system?

Some contaminants that are not removed by the reverse osmosis systems include organic molecules or dissolved solids smaller than a water molecule’s size. Since reverse osmosis membranes are designed to remove contaminants greater in size than water molecules, impurities like herbicides, pesticides, and chlorine are left behind.

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