Reverse Osmosis (RO) systems are an advanced way to treat and purify water. They guarantee that water is safe and clear as it filters out impurities. Most people who have tried it are impressed and have given good reviews. An RO system could have 3, 4 or 5 stages of filters. Along with the sediment and carbon filter, they also have an RO membrane. Read on to learn about the Four-stage filtration process that an RO water purifier has.

How does water purification work? - four stage water filtration process

The Reverse Osmosis system helps to remove even the tiniest impurities. It assures you that the water you drink is spotless and lacks impurities. The filter in a water purifier is built to rid you of odd tastes and odours in the water.

A four-stage water purifier works with the help of the following filters and membranes. Each of these is essential as they play different roles in the water purification process.

Stage 1: Prefilter

It is a sediment cartridge that removes dirt, sand and other particles from the water, along with taste, odours and chlorine.

Stage 2: Membrane

Water flows from the prefilter to the membrane. Most dissolved solids and other diluted substances are taken out and sent down the drain.

Stage 3: Post-Filter

If any odours or tastes are still in the water, the carbon postfilter will help reduce them. This is done before the water enters the storage tank.

Stage 4: Polishing Filter

Just before the water flows out of your taps, it goes to one last filtration stage. The activated carbon filter ensures that water that flows out tastes good and is crystal clear.  

Filers and Membranes used in the Water Purification Process   

Drinking water that goes to several filters and membranes is good because it filters out impurities, bacteria and tastes. This way, the water we drink is pure and will be good for our health. Drinking water with chemicals and particles can cause us to fall ill, get an upset stomach and even land in the hospital.

Keep reading to learn about the various filters and membranes of an RO water purifier. It might convince you to purchase one after seeing all the things it can remove from your water.  

1. Prefilter

A prefilter first filters tap water. Any physical impurities in it are removed.

2. Sediment Filter

The sediment filter aids in removing coarse and fine particles - like sand, rust, dust and dirt, from the water.

3. Pre-activated Carbon Granular Filter

This filter absorbs the remaining chlorine along with hazardous materials from the water. It could include herbicides, chlorine, pesticides, THM and others. Another thing it can do is absorb colour, bad taste and odours from water.

4. Reverse Osmosis Membrane

It is also known as the RO Membrane. Water flows through it at high pressure. It helps filter dissolved solids (including lead, arsenic, and radium), hazardous chemicals (pesticides, herbicides, heavy metals) and bacteria, protozoa and viruses. This membrane protects you from any microbiological threats.

5. Ultra Violet (UV) Disinfection Column

UV Radiation disinfects water. Any virus, bacteria or protozoa that could cause a waterborne disease are removed. This ensures that the water is microbiologically safe to drink.

6. Ultra-Filtration Cartridge

Bacteria, Cysts and Giardia are removed from the water. It removes fine impurities suspended in the water and thus improves its clarity.

7. Silver Impregnated Post Carbon Cartridge

This cartridge removes volatile organic impurities from the water. It makes the water taste better and improves its quality.

How does water filtration work? - The journey of water from the RO system to your Faucets

From entering the RO system to coming out of your faucets, the water goes through many filters and membranes. This is what happens-

1. First, water enters the RO system and goes through prefiltration. This step involves the carbon and sediment filters. They remove sediments and chlorine that are in the water and could cause damage to the RO membrane.
2. Next, the water flows through the RO membrane. Here, it removes any dissolved particles that are as tiny as an atom.
3. Once the water has been filtered, it flows to a storage tank where it is left till needed. The system keeps filtering water until the storage tank is filled. Then it shuts off.
4. When you open your faucet to drink water, the water flows through one last filter. The postfilter must do one final check and ensure you receive only the purest water.  

What can a reverse osmosis system eliminate?

An RO system is made to remove dissolved solids through the RO membrane. These include fluoride and arsenic. It also has a sediment and carbon filter for filtering out particles and tastes. Read on to see what else a reverse osmosis system can filter out:

• Fluoride
• Arsenic
• Salt
• Herbicides and pesticides
• VOC’s
• Chlorine
• Sediments

When should an RO Membrane be replaced?

A reverse osmosis system can last for about 10-15 years. Though the system remains in good shape for a long time, the filters require to be replaced.

The prefilters and post-filters must be changed about every six months to a year, and carbon, polishing or sediment filters must be changed every year.

An RO membrane lasts for about two to three years without changing, but it depends on the water. For hard water, it has to be changed every two to four years, while for soft water, you can change it every five to seven years. It works well and purifies the water just the same.

A booster pump can add additional pressure. This will increase the water flow in the RO system. While a permeate pump is meant to save water and increase the water the RO system performs.

In a Nutshell

An RO system is a great investment to make. It ensures that the water you drink is safe from all impurities. It keeps you healthy by keeping away bacteria and viruses.

There are many filters that each take care of removing a particular thing. These are all necessary to completely purify water. Water purification works to purify water and keep away harmful chemicals.