You might not be familiar with the name but you are very much familiar with its applications. Sales managers of water purifying companies repeatedly talk about how they supply the best water purifiers with the best Reverse Osmosis system. The technology itself, is indeed, undeniably a great invention. It shaded lights to reduce the cost of water purification. Furthermore, talking about beer, we all like to have it not too bitter, not too light. Reverse Osmosis plays a role here too! Intrigued? Let’s find out more.
What is Osmosis? How does it work?
We are all familiar with reversible reactions in chemistry. For our ease of understanding, let’s explore Osmosis first. Consider having a jar of two differently concentrated solutions, separated by a semipermeable membrane in between. This semipermeable membrane allows the motion of water molecules. No other chemical substance stands a chance. The question is which direction will the water move towards. The answer is, water molecules will move from the low concentrated solution to the high concentrated solution. The pressure experienced by the membrane during this process is the osmotic pressure. This mechanism is termed Osmosis. It is a completely natural process. Plant cells become wholesome with water when we water the soil. The cells take up water, go tight and hydrate. This is how plants stand upright. Now just like reversible reactions, the opposite gives birth to Reverse Osmosis.
Understanding Reverse Osmosis
Before the definition, let’s talk about the need for Reverse Osmosis for a while. We know the sea would be a great source of water. Certainly, seawater is inedible because it has tons of salt. What if we could remove this salt? Osmosis pushed water towards the region with more concentration. What if we could reverse this mechanically? What if we could squeeze water out from a region? Say hi to the technology of Reverse Osmosis. By definition, reverse Osmosis is getting the solvent out of the region of high concentration under pressure.
Membrane Designing for Reverse Osmosis
Let’s take some time to simplify the membrane design. Fundamentally, we have three layers, a polyester base layer, a polysulfone layer and a barrier of polyamide layer. The polysulfone layer is sandwiched between the base layer and the barrier layer. These stick together with a permeator layer on top. This permeator layer is allows only water molecules. Lastly, there is a net-patterned channel spacer that allows the water to get inside. Lumps of sediments and salt form against this layer. Later on, when the water leaves behind the unwanted residue, the residue exits through this channel spacer. The polyamide layer prevents germs and bacteria from entering the process. The base layer holds everything together strongly. This compact combination of sheets has a tube-like appearance. Lastly, resistant material shields them from both sides.
Feedwater passes from one side of the tube. This feed water is the water we want to filter. In other words, it has got impurities, we want out of the food chain. The other side has to release the filtered water. Remember the channel spacer? The channel spacer has a collection panel. The unwanted materials exit the system through this collection tube. Filtering water from this collection of residue honestly makes no economic sense. We already need a constant power supply to pump water into the system with high pressure. Yes, we are talking about electricity bills.
Facts Regarding the Reverse Osmosis System
If we talk about reverse osmosis as a household utility, we need just three or four tubes in the filtration system. In this case, the electricity bill is not that big. However, if we think about water purifying in an industry, we need to consider the electricity supply as a raw material. Tap water purifying companies which use reverse osmosis system across the world are Micronic Technologies in the USA, H2O Innovation in Canada, Nitto Denko Corp in Japan, Mascara Nouvelles in France, De.mem Pte Ltd in Singapore, Elemental Water Makers in the Netherlands etc.
Role of Reverse Osmosis in Purposes Other Than Purification
Heat-sensitive elements like protein are retained in fruit juices when reverse osmosis is used. Instead of heating and dehydrating the juice, we just squeeze the water out. Dairy firms also make smart use of Reverse Osmosis. Cheese comes from buttermilk. Reverse osmosis discards water from the milk. This saves the texture and composition of the lactic acid in milk. Also, milk powder is produced using this method. The water is excluded from Lactose. The Lactose is then processed to make a fine powder. Food syrups are also made using the same technique. Remember the beer in the introduction? Imagine water being discarded from the beer. Then the perfect content of water is added to give you the perfect taste, which is neither too bitter nor too watery. Sounds perfect? Yeah, the magic of Reverse Osmosis.
Role of Reverse Osmosis in Construction of Aquarium
Normal Tap water has a chemical composition that is unfit for water creatures with sensitive shells. Now Reverse osmosis can be used to concentrate the seawater mixture since these creatures are more used to the seawater. Then distilled water is added according to a fixed mark. As a result, an artificial environment has been made to take care of the water creatures.
Impurities and Pathogens Which Are Removed by the Reverse Osmosis System:
- Unwanted salts and anions
- Copper, Lead and Arsenic
- Fluoride ions
- Hard water elements
- Disease-causing bacteria
- Protozoa
- Virus
Advantages of Using Reverse Osmosis System at Home:
- Regular filters need the replacement of filter paper after a while. Filters that use Reverse Osmosis don’t need any such replacement. Everything is built-in.
- It is cheap.
- Easy to install.
- Available worldwide.
- It has easy maintenance.
- Easy to install.
The Downsides
- The electricity cost is the only issue we have to deal with as common people.
- In the industrial water purifying system, waste disposal is an issue. The waste takes place in sea areas. So this is contributing to land pollution. Then again, this has a solution. Chemicals treat waste before dumping.
- Filtration takes time.
- If the water is not fed under pressure the process will be delayed.
Future aspects
The idea of fusing reverse osmosis with electrodialysis develops for recovering important ions to improve the taste of drinking water. A pH balancer can also be installed in the system. Furthermore, the membrane layer is expected to be redesigned. This time water passes through double layers so that less electricity pumps the water into the system. Apart from this, better materials like nanoscales and graphene are also used to build more efficient membranes. These will prevent stubborn viruses from getting into the system.
Interestingly, the application of reverse osmosis has played a role as big as the application of osmosis. The other name of water is life. Purified water is just not a need. It is a right of every individual. With more and more air and water pollution in our environment, choosing a water source has become a matter of concern. So the need of purifying water is a necessity. The technology of Reverse Osmosis is just not an invention, it is also a realization that nature has a lot to offer if interpreted correctly. Grow a habit of drinking safe water to keep your immune system healthy during this challenging time of the pandemic.