How does Reverse Osmosis or RO water purifier work?

Factors to consider when buying a water purifier
RO purification

Most of us use Reverse Osmosis or RO water purifier at home. But do we know how does it works? The objective of this write-up is to explain the basic functionality of your RO in a very simple way.

RO stands for Reverse Osmosis which simply means that it is the opposite of a process called Osmosis. So let’s first understand the Osmosis Process.

What is Osmosis?

There is a natural tendency of fluids or solvents to pass from a lower concentrated solution to a higher concentrated solution through a semipermeable membrane or film. Semipermeable membrane is a film that allows only the fluid or solvent to pass but not the salts and impurities dissolved in it.

In the below diagram, fresh water has lower salt concentration compared to the salty water on the other side of the membrane. And therefore fresh water flows towards salt water (i.e. from lower concentration towards higher concentration)

Osmosis explained

Osmosis process explained

The simplest example is the passage of water from soil (soil has a higher concentration of rich salts and minerals) to the roots of plant.

Plant osmosis

What is RO (Reverse Osmosis?)

RO (Reverse Osmosis) is just the opposite of the above process. Osmosis occurs naturally without requirement of any energy from an external source. But in reverse osmosis (RO) pressure is applied to the higher concentrated solution. This energy or pressure should be higher than the natural osmotic pressure. Because of this pressure, salt water moves towards the fresh water through the semipermeable membrane, leaving behind the impurities, bacteria and ions.

reverse osmosis explained

Reverse Osmosis

Inside our RO (Reverse Osmosis) firstly the water from the supply or tap (called the feed water) enters the pre-filter where the filter cartridges remove the initial dirt and sand. Then with the help of a pump this filtered water (which still has lots of impurities and salts) is made to pass through the semi-permeable RO membrane. This semipermeable membrane allows only the water to pass through it leaving almost all the dissolved salt, impurities and bacteria behind called the reject Stream. The amount of pressure required depends on the salt concentration of the feed water. Higher is the concentration of feed water, higher is the pressure required to overcome the osmotic pressure. The water coming out of the RO membrane is called Desalinated water. This water is free from almost all impurities. And finally this RO filtered water is passed through the post filters or the carbon filters which remove any remaining odour or taste from the water. Now your water is purified and ready to drink.

RO process explained

Functionality of RO water purifier

You need to get your RO service done in every three months, which includes cleaning or change of filters and membrane along with the cleaning of water storage tank. If your Reverse Osmosis or RO water purifier is not working or you need help with RO repair and maintenance, RO filter change, RO membrane change in Delhi and NCR, will find you the best RO maintenance companies in Delhi NCR, Noida, Gurgaon

Home repair was never this easy. 

Mr Right – Making India Smarter

You might also like


  1. 1

    This is such an informative post! Reverse Osmosis (RO) technology is truly a game-changer when it comes to ensuring the safety and purity of our drinking water. Netsol Water commercial RO plant water purifier is the best water purifier company in India.

  2. 2

    I particularly appreciate the emphasis on pre-filtration, underscoring its importance in enhancing the longevity and efficiency of the RO system. It’s a reminder that every stage in the process plays a significant role in delivering high-quality, purified water to our homes.

  3. 3

    Thank you for the insightful explanation of how a Reverse Osmosis (RO) water purifier operates! The process of water purification through RO is truly fascinating. The way it utilizes a semi-permeable membrane to separate impurities from water is nothing short of a technological marvel.

  4. 4

    This is such an informative post! Reverse Osmosis (RO) technology is truly a game-changer when it comes to ensuring the safety and purity of our drinking water. The way RO water purifiers work is fascinating – the semi-permeable membrane filtering out impurities and contaminants, leaving us with clean, great-tasting water

  5. 5
  6. 6
  7. 7

    so i basically want to talk about water purifies since we are discussing water and energy conservation. Are all purifiers actually same? Do they really work is their any difference bw technology? The thing about all water purifiers is that they are based on same technology but if we talk about something different I would suggest “Eureka Forbes UAE” in terms of their water purifiers which use RO and UV water purifying technology they are really great in terms of energy saving and taste, along with this they also offer other unique water solutions and products from domestic to industrial level, but I personally recommend Eureka Forbes Dubai for their customer service which is really fast, responsive. If you are here looking for a best water purifier or water processing technologies i.e. UV Sterilizers, Water Softeners, Fine Sediment, Water Filter etc they are using MURAL CRM ( for customer management and service scheduling,
    #waterfilter #waterfilters #aquaguard #eurekaforbes #bestwaterpurifiersindubai #DubaiWaterFilters #EurekaForbesDubai #DubaiROFilters #AquaGuardRO

  8. 8
  9. 9
  10. 10
  11. 11

    RO or reverse osmosis is one the necessary process for purifying the water. This post is very nice.
    Blue Mount Ro water purifier is the best water purifier company in India. Here customers get the best alkaline water purifier from Flipkart also.

  12. 12
  13. 13
  14. 14
  15. 15
  16. 17

    Ro water purifier works the behalf of own technology because every has own new technology like Minjet technology . Several brands are provide water purifier and they also want to provide better service on daily basis.

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>