As the most popular filtration method, reverse osmosis can not be ignored. With the help of a semi-permeable membrane, reverse osmosis can remove most of the impurities in the water.

It is an efficient, energy-saving, and environmentally-friendly filtration technology, which has been widely applied to commercial, industrial, and residential uses.

As theaPouring water into glass on blue background most popular filtration method, reverse osmosis can not be ignored. With the help of a semi-permeable membrane, reverse osmosis can remove most of impurities of water. It is efficient, energy-saving and environmentally-friendly filtration technology, which has been widely applied to commercial, industrial and residential uses.

If you are still not familiar with this technology, reading this blog can help you have the concept of RO(reverse osmosis) and know this popular filtration method. It will according to the basis, working principle, advantages, and different types of RO membranes introduce RO.

What is reverse osmosis?

You need to be aware of a seagull story before we discuss RO. A scientist in the United States accidentally discovered in 1950 that seagulls took a sizable mouthful of seawater while flying at sea and spit out a smaller mouthful after a short period of time.

This raised questions, and an investigation was done to find that the seagull has a thin membrane inside it that is extremely finely built. Seagulls filter seawater across this membrane into consumable water, while spitting out seawater that contains pollutants and salts that are highly concentrated.

reverse osmosis

Reverse osmosis (RO) is a water purification process that uses a semi-permeable membrane to separate ions, unwanted molecules, and larger particles from drinking water.

In reverse osmosis, an applied pressure is used to overcome osmotic pressure, a colligative property that is driven by chemical potential differences of the solvent, a thermodynamic parameter.

Reverse osmosis can remove many types of dissolved and suspended chemical species as well as biological ones (principally bacteria) from water and is used in both industrial processes and the production of potable water.

reverse osmosis

In the normal osmosis process, the solvent will go through a membrane from an area of low solute concentration to a higher concentration.

Applying an external pressure to reverse the natural flow of pure solvent, thus, is reverse osmosis. The process is similar to other membrane technology applications.

What contaminants are removed from water?

RO membrane will prevent contaminants with particle size of more than 0.1nm in effective diameter from going through. Generally, more than 90% of ionic contamination, most organic compounds and effectively all particulates could be removed.

The removal of RO of non-ionic contaminants may be low for MWs (molecular weights) of <200 Dalton, but it increases at higher MWs.

In theory, when molecules with MWs > 300 Dalton, all contaminants including particles, colloids, microorganisms, and large biologically active molecules will be rejected completely. But dissolved gases will pass through.

Bacteria, Suspended matter, Giardia, Yeast Cryptosporidium Protein, Virus Salt, Colloid, Insecticide Salt
Protein, Virus, Salt, Colloid Salt, Colloid, Insecticide Salt Water
Micro Filtration Ultra Filtration Nano Filtration Reverse Osmosis

How does reverse osmosis work?

In the reverse osmosis process, feed water is pumped through the input side of the reverse osmosis membrane under pressure (usually 4-15 bar, 60-220 psi) in crossflow.

Generally, 15-30% of the feed water passes through the membrane as permeate, and the rest remains on the inlet side and is discharged as a concentrated liquid stream that contains most of the salt, organic matter, and substantially all particles.

How does reverse osmosis work

Advantages of Reverse Osmosis Membranes

RO is a simple and energy-saving filtration method, it has lots of benefits. What’s more, RO is an environmentally-friendly filtration technology while it has high efficiency.

  • No heating required, no phase change
  • Simple equipment and small footprint
  • Easy to operate, a wide range of application
  • Low energy consumption and high efficiency
  • The high degree of automation, good quality of effluent
  • No pollution to the environment

The different usage of RO

RO membrane is mainly used in commercial, residential, and industrial applications. The following introduction helps you know it more clearly.


commercial use

Water that is pure, clean, and healthful is desperately needed on a global scale. Businesses including workplaces, schools, hotels, and restaurants may give customers and staff with high-quality, pure water that is free of all sediments, pollutants, and hazardous compounds by employing commercial RO membrane.

While these systems are used for drinking reasons in schools, universities, and commercial buildings, the food and hospitality industry uses commercial RO water purifiers for both cooking and drinking.



For many people, who want to drink high-quality and high-purity water at home directly, the RO membrane is a perfect choice.

TDS is made up of dissolved in water inorganic salts and trace amounts of organic materials. For instance, hard water is caused by an excess of the salts calcium, sodium, potassium, and magnesium.

While naturally occurring in water, these organic substances might harm your health if you ingest them in excess. Using a RO membrane to purify water can effectively solve this problem.



By using proper RO membranes, they help to reduce contaminants in various industries such as municipal water, desalination, boiler feed water, wastewater treatment, and spot-free rinse. With the help of high efficiency and high purity of RO, those industries can keep the productivity with the required water.


RO membrane is by far the most effective technology which can remove more than 90% of contaminants from water. It is preferred by many people and applied to a variety of industries.

We believe this article can let you simply and easily understand what reverse osmosis is, and realize what can be removed by reverse osmosis.

Brother Filtration has years of experience in the filtration field and can provide you with high-quality RO membranes and membrane vessels that fulfill different usages. If you have any questions about RO, please feel free to contact us.

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