What Are Reverse Osmosis Membranes Made Of

Reverse osmosis is a filtration method that thoroughly cleanses water away from harmful toxins. It is widely used by companies and households alike because of its cheap maintenance and filtration capabilities.

Its membranes are made of three layers which are the polyester web, a microporous polysulfone inner layer, and the outer polyimide layer. 

If you are eyeing on getting your own reverse osmosis system, then knowing how it works is a must.

There are plenty of water filtration methods available in today’s time. One of the most popular among them is reverse osmosis. And today, we are going to take a deep dive into the matter.

How It Works

To help you better understand reverse osmosis, you need to know how osmosis works first. Osmosis is a naturally occurring phenomenon where molecules pass through a semipermeable membrane.

Reverse Osmosis Works
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Thus, creating a less concentrated solution into a higher concentrated one.  And since it occurs ‘naturally’, it doesn’t need any kind of pressure for the molecules to pass through.

A prime example is found in the things around you. Such as the roots of the plants gathering water from the soil where it’s planted. Or where you stay in the pool for too long and your finger skins get pruned. 

Reverse osmosis, on the other hand, works by filtering molecules through a semipermeable membrane with the help of pressure.

It is most commonly used for water filtration to keep it free from toxins and contaminants that are harmful to one’s health. Reverse osmosis makes water not only clean but also more delicious to drink as well. 

Distilled water systems share similarities with reverse osmosis devices. But it all boils down on the effectiveness of such filtration methods.

Distillation only removes contaminants on the surface level. Where reverse osmosis removes all of them completely including chlorine, sodium, and lead just to name a few.

This is why water that is treated using reverse osmosis is said to be ‘100% pure’, but this also results in some caveats too. For instance, reverse osmosis water doesn’t contain any minerals since it is also filtered out as well. 

Some people believed that this isn’t a problem since you can get minerals from other sources. This includes eating foods rich in minerals such as fruits and vegetables or taking food supplements. 

Inside A Reverse Osmosis System

Now that you know how reverse osmosis filters out water contaminants, it’s time to see what’s inside the system itself. In this section, we are going to focus on its membranes first. These membranes are the main component of a reverse osmosis system.

Inside A Reverse Osmosis System
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They act as a barrier to filter out pathogens for a cleaner and safer to drink water. These membranes are made out of three layers.

And these are:

  • Outermost layer – Polyimide barrier
  • Middle layer – Microporous polysulfone 
  • Inner layer – Polyester layer (acts as a support web)

These three layers are so thin that you can only see them in full using a microscope. It is also made up of multiple sheets for extra filtering efficiency. Reverse osmosis systems have three canisters. One of them is for the membranes, and the other two are for the carbon filters. 

1. Pre-filtration stage

In the first step of the process, the water goes through the first canister which is called the carbon block filter. This is the process where the water is cleared out of dissolved solids. But keep in mind that you should never put hard water in an RO system. 

Doing so is a recipe for disaster and may possess serious problems in the long run such as damaging your RO system. You might want to invest in a water softener system if that is the case. 

2. Filtration stage

This stage is where the membranes start to do its thing. Once the water is pre-filtered in the carbon block canister, it then goes to the middle one where the membranes are. 

In this canister, the water passes through the semipermeable membrane with the help of pressure. This is where contaminants such as chlorine, lead, sodium, and other kinds of bacteria are blocked. 

Do keep in mind that the three-layered membrane has small holes. And since contaminants are made up of large molecules, they have filtered thanks to the membrane. Leaving only pure and clean water to pass on to the final canister.

3. Post-filtration stage

Now that the water is filtered and clear from contaminants, it passes through the post-carbon filter. What this filter does is getting rid of contaminants that may not be removed by the membranes. Once done, It is then transferred to the water tank where it is now ready to drink.

A Reverse Osmosis System Is All You Need

If your household is relying on tap water for your cooking or drinking needs, then investing in a reverse osmosis system is a must. Not only does it provide your family with healthier and safer drinking water, but you also save money in the long run as well. 

Reverse Osmosis System
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Do keep in mind that reverse osmosis systems are larger than an ordinary distilled water system.

So you might want to hire a professional to help you during the installation process. But luckily, there are also portable reverse osmosis systems that are available in the market today. What’s best is that they also cost less too. 

But its effectiveness may not be on par with its bigger counterpart. But if you want to try reverse osmosis water for the first time, then these portable RO systems are the way to go. You can find a lot of them online that come at affordable price tags that are under $120. 

By owning a reverse osmosis system, you don’t have to order distilled water just to get clean drinking water. It’s a one-time purchase that can last for years.

And you only need to maintain it quarterly as well. So what are you waiting for? There’s no better time to order a reverse osmosis system than now and enjoy its benefits.

How does reverse osmosis work?
Jomar Teves

A blogger by day, a tech enthusiast by night, and a downhill mountain biker at the weekends. After four years in business school and working for multinational clients, Jomar believes he can improve the world through his writings. Jomar has six years experience as a writer and is a graduate of the BSBA Entrepreneurial Marketing program. His work has been published on Clutch Points, Blokt and iTech.