Does Reverse Osmosis Remove Bacteria? [Read This]

How Does Reverse Osmosis Remove Bacteria?

Water allows viruses and bacteria to enter your body. Is drinking bottled water a means of avoiding contamination? Why is reverse osmosis system the best decision? How does it function?

If viruses are present in the water you drink or that comes out of your kitchen faucet, they could go into your mouth and then into your body. Don’t you think that sounds awful? After all, without water, we cannot survive. How do we obtain clean water?

Although bottled water is secure, most supermarkets impose a cap on the quantity that can be purchased. A lot of folks also lack the means to purchase enough water. Many families have invested in water filters to ensure that they have access to enough clean water.

However, the environment restricts the installation of conventional water filters. Traditional water filters also have poor performance and are favourable environments for the growth of microorganisms. A reverse osmosis water filtering system is the best option as a result.

The size of the virus is between 0.02-0.25 micron, which is significantly smaller than the diameter of viruses, and the reverse osmosis (RO) membrane in a RO system has a minimum pore size of about 0.1 nm. Without a doubt, a reverse osmosis system can successfully eradicate viruses.

Type of Bacteria Present in Your Water

Escherichia coli (E. coli), Fecal Coliforms, Campylobacter Jejuni, Pseudomonas aeruginosa, Giardia lamblia, Cryptosporidium, Listeria Monocytogenes, and Salmonella Typhimurium are some common pathogens that may be present in your water source.

These bacteria can result in conditions like diarrhoea, pneumonia, hepatitis A, typhoid fever, and other gastrointestinal issues if left untreated.

Let’s examine some of the germs found in tap water and how to get rid of them.

  • Escherichia coli is a bacteria that can be found in homes, schools, hospitals, and any other place where there are people. It can cause diarrhoea when consumed in high concentrations through drinking water.
  • The most typical cause of food-borne gastroenteritis is Campylobacter Jejuni (diarrhea). Additionally, it can be discovered in tap water that has come into contact with bird waste in places including farms, hatcheries, slaughterhouses, and live poultry markets.
  • Stool germs called faecal coliforms have been linked to gastrointestinal issues like cholera and achy stomachs.
  • When Pseudomonas Aeruginosa bacteria are present in high concentrations in water, they can infect the eyes and nose. It may also result in pneumonia and skin infections.
  • When consumed, the protozoan Cryptosporidium can result in diarrhoea and is spread through tainted water. Due to contamination from contaminated food, human sewage, or animal waste, it can also be detected in tap water.
  • Giardia Lamblia is a type of parasite that can infect water supplies such as lakes, ponds, rivers, and streams and cause intestinal diseases in humans. It has also been discovered in tap water.

Salmonella Typhimurium is a bacterium that, if consumed, can result in food poisoning. It is frequently spread by eating improperly prepared food, although it has also been discovered in tap water.

These are some of the most prevalent germs found in tap water that, if left untreated, could be dangerous to your health.

Health Effects of Bacteria In Water

Every immune system, regardless of strength, is susceptible to polluted water.

Pathogens like bacteria can lead to:

  • Diarrhea
  • Vomiting
  • Cramps
  • Nausea
  • Headaches
  • Fever
  • Fatigue

However, only those with compromised immune systems need to be concerned about potentially fatal consequences.

How Does Reverse Osmosis Work?

The fundamental reverse osmosis filtration procedure is divided into 5 stages:

  • Sediment and Carbon Pre-Filtration
  • Semi-permeable .0001 micron reverse osmosis filter membrane
  • Storage tank
  • Post-Filtration and
  • Remineralization

In essence, a reverse osmosis filter passes water through various filtration steps in order to separate the pure water from contaminants and particles larger than water molecules.

How Does RO Remove Bacteria?

Systems for reverse osmosis filter water at various stages. A carbon filter, a sediment filter, and a post-filter are a few of the filters that water goes through. However, if you are familiar with water treatment, you are aware that most filters are unable to remove microorganisms.

Bacteria can easily pass through the cracks in most filters because their pores are between 1 and 5 microns wide, which is smaller than most water molecules.

Reverse osmosis systems are unique in that your water supply will be passed through a semi-permeable membrane after being filtered. Since the membrane’s pores are so small (0.0001 microns), it can serve as a sieve to trap almost all contaminants, regardless of size.

The minuscule pore size of this membrane prevents even microscopic microorganisms from passing through. Only water molecules can cross the barrier; bacteria and viruses, such as hepatitis and salmonella, are swept away with wastewater.

Do not be misled; reverse osmosis technology cannot eradicate viruses or germs. It simply makes sure they are removed, leaving you with completely pure water. UV treatment is the finest option if you’re seeking for something to kill these germs.

How Much Bacteria Does Reverse Osmosis Remove?

When it comes to eradicating bacteria and viruses from drinking water, reverse osmosis is very effective. These impurities are classified as organic material, and an effective reverse osmosis filtration system may eliminate microorganisms with up to 99.9% efficacy.

Reverse osmosis may effectively eliminate a variety of germs and viruses, including Campylobacter, Shigella, E. coli, Salmonella, Hepatitis A, Rotavirus, and Norovirus.

Other Contaminants Reverse Osmosis Water Filters Remove

Reverse osmosis systems may remove a wide range of contaminants from a drinking water supply in addition to organic matter. The reverse osmosis membrane can actually filter up to 99.99% of the total dissolved solids (TDS) in water.

Chemicals like chlorine, heavy metals like lead, hardness minerals like calcium and magnesium, and other chemical and organic pollutants that could harm our health, such as fluoride, radium, nitrate, and potassium, are among of the contaminants that a RO system can remove.

Disadvantages of Reverse Osmosis Systems

Removes Healthy Stuff

One of reverse osmosis’ main drawbacks is that it almost works too well; it also eliminates beneficial elements like healthful minerals from water. Even while we obtain many of these minerals in large quantities from food sources, you might like the thought of obtaining a small amount more from your drinking water source.

Some individuals also believe that water devoid of minerals has a “flat” or “boring” flavour. While you can reintroduce some minerals to your water, it would be preferable if they had never been filtered out in the first place.

Generates Wastewater

Although reverse osmosis filtration’s efficacy cannot be contested, the system’s effectiveness falls short. Reverse osmosis systems by their very nature waste water while purifying it; the ratio of wastewater to pure water is typically 4:1.

This implies that a sizable amount of your water won’t actually exit your tap. It will instead be washed away. In order to prevent a buildup of impurities that could harm the membrane in the reverse osmosis chamber, water must be wasted during RO. When water is flushed away, pollutants are also removed.

Expensive Price Tag

It’s hardly surprise that reverse osmosis system experiences are expensive because they are thought to be the finest way to remove anything from viruses and bacteria to chlorine compounds. For a system for under-sink or whole-home use, you’ll typically need to spend at least $400.

Requires Maintenance

Reverse osmosis systems require maintenance once they are installed, so keep that in mind as well. Depending on the unit you choose and whether it is a small system installed at your faucet or a bigger one installed at your home’s point of entry, the precise upkeep required will vary.

The reverse osmosis membrane should be replaced every two years, while RO filter cartridges should be changed about every six to twelve months. Owning this kind of water purification technology entails crucial and unavoidable maintenance.

Considerations for Choosing an RO System

System Type

Asking yourself what you’re searching for in your search is important because there are many various types of RO systems available on the market today. Although point-of-entry systems may be a better option if you want to ensure that your entire home has access to safe, clean water, under-sink tap water devices are still the most common.

The popularity of many countertop RO filter products has increased recently. These systems function admirably as a more transportable option; they may be helpful for those who reside in rental homes.


You should include at least $300 for a reverse osmosis system in your budget. Certain RO systems might cost up to $1,000. The initial cost is the highest, but remember to set aside some money for the annual filter changes, which are typically less expensive at $30 to $60 per pack.

Efficiency Ratio

The normal RO filter efficiency ratio, as I just indicated, is 4 gallons of wastewater to 1 gallon of pure water produced. However, manufacturers started working on more effective RO systems in recent years, with wastewater to clean water ratios of 3:1, 2:1, and even 1:1.

Although these units often cost more up front, the savings you will ultimately receive from long-term use may make it a beneficial investment for you in the long run.

Water Quality

The effectiveness of your RO system may be impacted by your water quality so keep that in mind when you conduct your search. A high pollutant level will probably impact the filtering procedure and shorten the life expectancy of the filter and membrane.

The pace of filtering should not be impacted by your water quality, though, if your water pressure is high enough.

Additional UV Addon

While RO filter is capable of eliminating the majority of bacteria and viruses, if your water source has a lot of these impurities, employing a UV light can assist provide that extra confidence.

As its water treatment process includes destroying germs rather than eliminating them, a UV add-on is a chemical-free option that will guarantee your water is 100% safe to drink.

Other Ways To Remove Bacteria

Here is a quick comparison of RO’s competition for the elimination of bacteria:

  • UV Systems: UV light is used to kill microorganisms. VERY HIGH EFFECTIVENESS..
  • Distillation Systems: Water is boiled, and the steam is collected. VERY HIGH EFFECTIVENESS..
  • Filters with tiny pores are called microfiltration filters (approx. 0.1 micron). MODERATE EFFECTIVENESS
  • Filters with incredibly small holes are used in ultrafiltration (approx. 0.01 micron). VERY HIGH EFFECTIVENESS..
  • A filter with nanoscale pores is a nanofiltration filter (approx. 0.001 micron). VERY HIGH EFFECTIVENESS..

Frequently Asked Questions

How does reverse osmosis remove bacteria?

Common bacteria like Escherichia coli have an average diameter that spans from 0.2 to 4 microns. The holes of RO membranes, which have a size of 0.0001 microns, are too huge for this size to pass through.

Pure water is produced as the filtrate when polluted water flows through the semipermeable RO membrane, while bacteria are retained as the residue thanks to the.0001 micron filter. Bacteria are not killed or rendered inactive by reverse osmosis.

Reverse osmosis remove bacteria from the tainted water via sieving. While the filter membrane holds onto the biological pollutants, you receive pure water.

Which Microorganisms Is Removed by Reverse Osmosis Unit?

The Center for Disease Control and Prevention (CDC) claims that reverse osmosis systems may purge water of protozoa, bacteria, and viruses.

RO is efficient at removing microorganisms like:

  • E. coli
  • Salmonella
  • Campylobacter
  • Shigella
  • Giardia
  • Cryptosporidium
  • Enteric
  • Rotavirus
  • Norovirus
  • Hepatitis A

How Effective Is RO Against Removing Bacteria?

Your reverse osmosis system should be able to eliminate 99.9% of organic pollutants once it has been installed correctly. Pathogenic microbes including bacteria, viruses, fungus, and protozoa make up the organic matter in water.

Keep in mind that semi permeable membrane deterioration and fouling are two factors that could reduce the efficacy of RO in removing bacteria. RO membrane replacement is a good idea every two to three years. A damaged membrane is unlikely to function properly.

What other common contaminants can RO system remove?

RO systems are also excellent in purifying water of chemical impurities and material pollutants. The effectiveness against specific pollutants varies, but generally speaking, it ranges from 95 to 99% of total dissolved solids (TDS).

Aluminum, Barium, Iron, Chromium, Chloride, Arsenic, Fluoride, Manganese, Copper, Magnesium, Calcium, Lead, Cadmium, Zinc, Magnesium, Mercury, Nitrate, Sulfate, Sodium, Potassium, Silver, Radium, and Chromium are just a few ions and metals that can be removed by RO membranes.

Additionally, organic substances like benzene, toluene, trihalomethanes, carbon tetrachloride, trichloroethylene, and dichlorobenzene can be eliminated by the membranes.

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