How Does TheReverse Osmosis System Work?

Have you ever tasted the water that belongs to someone who has a reverse osmosis system at home? If so, it is apparent that you are already aware of the pleasant taste of this water. 

Reverse osmosis produces drinking water that is undoubtedly considered the best for every family. This water will not only taste good, but it ensures that your entire family remains safe and healthy as they drink water that contains no contaminants at all because the water has undergone proper purification. Nevertheless, it is crucial to understand how this process works. This article aims to simplify the mechanism by which reverse osmosis can turn muddy water into sanitary and safe potable water that tastes fresh. 

Osmosis is when the molecules can pass through the semi-permeable membranes from a less concentrated liquid to a more concentrated solution. Reverse osmosis is nothing but the reversal of this process. The process enhances the quality of water for cooking, drinking, and any other essential uses that require clean water.

How Does Reverse Osmosis Work?

As the name states, reverse osmosis is an inverse of osmosis, a biological process in cells through cell membranes in plants, animals, and even people. To understand reverse osmosis, it is essential to understand what osmosis is. Osmosis is the process where molecules move from a more dilute solution to a concentrated solution. For example, a piece of potato placed in salty water loses water to the environment because it is less concentrated compared to its surrounding.

The following is an explained step of the reverse osmosis process:

  1. The process is a bit different from osmosis because, unlike osmosis, which occurs naturally, reverse osmosis requires applying pressure, an external force to operate.
  2. Pressure is applied to the high concentration solution, such as borehole water which is salty to an area of low concentration through a semi-permeable membrane.
  3. The membrane allows only a few molecules like the water molecules to pass through, excluding larger molecules like the contaminants.
  4. The process separates a higher concentration of solute on one side and allows the solvent, the freshwater, to collect on the other side.

The Mechanism Of The Reverse Osmosis Water Filtration System

Reverse osmosis is an innovative technology used for removing most of the harmful contaminants from the drinking water by pushing it under a lot of pressure through the semi-permeable membrane. The system changes depending on logo and design, but all systems perform the same functions. It is also known as the RO system, in which you can deionize or demineralize water and make it tasty.

There is a lot more to this process when using the reverse osmosis system to purify the drinking water. Listed below are the following steps that clearly describe how does a reverse osmosis system work. If you are interested in an RV water filter that has an RO system, read this article.

01. Pre-chlorination dosing

Most of the time, the feed water contains heavy metals, which are water contaminants. In this process, the feed water is dosed with chlorine which changes the heavy metals that have dissolved in the water to physical or seen materials, which the filter will be able to remove most of it.

02. Raw water storage tank

Some reverse osmosis systems can draw water directly from the source, such as borehole, well, or even the pipe. Still, most reverse systems start with a considerate storage tank whose work is to store the contaminated water. Less feed water can destroy your pump, and therefore, it is essential to have a large storage tank to ensure that your pump lasts as long as possible

03. Feed water pump

The feed pump is used to provide the initial pressure for the system. The force generated by the pump should be enough to get the water through any pretreatment or the reverse osmosis membranes. If the pump cannot provide enough pressure, a booster pump will be necessary to meet the required pressure.

04. Pre-filtration

This step is meant to protect the membrane. It helps remove the larger sediments of the dissolved solids and plays an essential role in reducing chlorine.

The first cartridge is the carbon block or the sediment filter, which has a good solution that reduces smell, bad taste, remnants of organic waste, and chlorine from the water. The membrane tends to get damaged due to the excess sediment or too much chlorine present in the municipal water.

05. The reverse osmosis membrane

The water is typically forced through semi-permeable membranes under immense pressure. This membrane is nothing but a plastic material, which allows the water molecules to pass quickly. However, chlorine, calcium, sodium, and large molecules of urea, glucose, viruses, and bacteria cannot pass through this membrane.

Reverse osmosis drinking water systems have been tested and certified to reduce:

  • Lead
  • Copper
  • Arsenic
  • Nitrites and Nitrates
  • Selenium
  • Chromium
  • Radium
  • Fluoride
  • Cadmium
  • Barium
  • Total Dissolved Solids
  • Cryptosporidium

Reverse osmosis can produce a million liters of clean water with a small amount of waste. Usually, the wastewater can be left down the drain, but it is essential to check with the local water authorities if the wastewater needs to be handled with care.

06. Multi-layer or media filter

There are some things the reverse osmosis can not remove if we may not want to admit it. A common contaminant known as nitrate found in fertilizers and organic matters is an excellent example of the materials that dissolve in water so well that the reverse osmosis system can not remove them. The reverse osmosis system can not be prevented or removed from bad taste and bad smell. For this reason, a multi-layer filled with media that targets precisely this kind of contaminants that can not be removed by reverse osmosis is used. This stage is necessary if you would like to remove this kind of contaminant from your water.

07. Automatic water softener

Water softeners help remove the hardness of the water. It helps in changing hard water to soft water. It also removes calcium and magnesium ions. For people using small reverse osmosis, it is advisable to use automatic water softeners rather than an antiscalant chemical dosing system.

08. Product water storage

The water from the reverse osmosis process usually goes to a large storage tank. If the system does not have a storage tank, the system must run all through to get enough and continuous supply of fresh water, which is not so convenient for anyone. Sometimes the system pumps water into a well or an aquifer to recharge.

09. Post Filtration

Before the water becomes ready to drink, it also goes through the second carbon filter or the post-filter, which can remove the remaining contaminants, as there are chances that they can slip through the membrane. Once all the impurities are removed, the water is filled up in the storage tank and waits there until you are ready to use it.

10. The Final Polish

After this, the in-line activated filter helps in giving the water a final and last polish when the water begins coming out of the faucet. This helps remove the flavors and odors that may come from your holding tank or perhaps all the system hoses. The polish ensures that your water tastes fresh and healthy.

What are the Basic Components of a Reverse Osmosis System?

grayscale photo of wine glass

Like any other system under operation, the reverse osmosis system comprises five essential parts, which are explained below.

01. Pressure vessel and membranes

The system would be useless without the membranes because that is where it gets its osmosis factor from. The membranes are made up of different proteins depending on intake and end clarity. Membranes are designed to remove specific contaminants like there is a membrane designed purposely for water treatment. For example, there are other membrane elements for seawater and hospital-grade disinfection. The size and the number of reverse osmosis membranes depend on the weight of the task at hand. These tasks include commercial, industrial, municipal and domestic.

02. Reverse osmosis skid

It is a carbon steel frame coated with powder, and it is used to mount all other components. It is helpful in that it ensures the reverse osmosis system lasts long enough. It is resistant to contaminants in reaction, and it is also designed to accommodate higher vibration from the heavy pumps. It rests on the ground, a condition that helps it to last for many years.

03. Cartridge filter

It is the part that ensures that larger particles that can destroy the membranes do not come any closer to the membranes. It is usually made of a five-micron spun polypropylene filter, but one can change it depending on the customer’s desires or the kind of task the reverse osmosis would do. It operates in a metal casing that can last for a long time and handle the pump or booster pressure without failure.

04. Reverse osmosis high-pressure pump

Most commercial and industrial reverse osmosis can only be relied on if they have a high-grade pump. The type of pump used in any system must be checked and verified to match the size and the quality of the membrane in that system. Typically, the higher the pumping power in the intake pump, the better the reverse osmosis water produced.

05. Control panel

The last part of the reverse osmosis system is the control panel operated by a human operator. The controls can be used to manage different techniques at the same time, which lowers the amount of human labor required because only one person will be required to operate the plant.

Apart from the five components discussed above, a reverse osmosis system may contain other components built-in or onto it to make extra components.

What Does Reverse Osmosis Remove?

Reverse osmosis plays a vital role in removing salt, iron, manganese, fluoride, lead, and calcium. Most of the mineral components of water are more significant in comparison to the water molecules.

Therefore, they can be trapped by the semi-permeable membranes and easily be removed from the drinking water when filtered through reverse osmosis. This unique method helps remove the sodium and the dissolved solids, which makes the water soft and appropriate for usage.

Removal of Minerals

Reverse osmosis is responsible for removing around 99% of the harmful contaminants, including the minerals from the supply of drinking water. The advanced filtration system helps in eliminating minerals because the molecules are more significant than that of water. Though minerals are necessary for the body, tap water also contains inorganic minerals, which cannot be consumed by the human body quickly.

Inorganic minerals can cause a number of degenerative diseases like hardening the arteries, kidney stones, arthritis, glaucoma, gallstones, hearing loss, diabetes, obesity, cataracts, and emphysema. The cellular tissues can reject the minerals present in the hard tap water. Reverse osmosis helps remove these minerals as their presence may lead to the obstruction of the arteries and internal damage.

Straining Impurities

For years, reverse osmosis water filtration has been highly efficient in removing the unwanted impurities from the water cost-effectively and efficiently.

Reverse osmosis is capable of removing a number of other impurities other than inorganic minerals. These impurities include:

  • Water Microns
  • Aqueous Salts
  • Poliovirus
  • Carbon Block
  • Smallest Possible Bacteria
  • Tobacco Smoke
  • The Smallest Yeast
  • Human Hair

Therefore, the reverse osmosis system is becoming more popular with time.

What Types of Water Sources Does Reverse Osmosis Treat?

three clear drinking glass on table

Reverse osmosis is the best solution in water treatment in most types of water. There are three categories of water that are differentiated by their total dissolved solids. These categories include groundwater, tap water, and saltwater. There is a minimal value of total dissolved solids required in drinking water given by the health association.

Tap water moves through fixed piping or damming system. It contains some rust particles which are because of traveling through metal pipes. Reverse osmosis is used to remove hardness in tap water and remove the contaminants resulting from the metal piping. The process of purification targets the amount of total dissolved solids.

Underground water or reservoir contains large amounts of salt but not a lot enough to become salty water. Reverse osmosis is used to purify this type of water for agriculture or domestic use. Underground water is also a significant source of bottled water, with a unique mineral combination giving it some sweet taste.

Reverse osmosis turns salt water into drinking water which means it softens hard water. A borehole must be dug in the ocean for reverse osmosis to be carried out on ocean water. This type of purification is most important in areas that lack enough supply of freshwater.

Is Pretreatment Necessary?

Feedwater must be conditioned before it reaches the membrane of reverse osmosis to avoid destroying the membrane. Preconditioning also increases the lifespan of the membranes. The membrane is constructed to allow water to pass through and prevent the passage of other dissolved materials left at the surface of the membrane. These sieved materials are disposed of as waste.

As reverse osmosis continues, dissolved contaminants and other solids accumulate upstream of the membrane. Failure to remove these materials will interfere with the flow of reverse osmosis water, causing a drop in water production. Earlier in the development of the reverse water membrane, the developers knew very little about the blocking of the membranes. Still, to date, most of the contaminants in the feed water have been identified. The best methods to treat them have been developed, reducing membrane blockage, hence increasing the membranes’ lifespan.

What Determines the Precise Pretreatment for a Particular Reverse Osmosis?

You can never understand the kind of contaminants in your water until you do a water analysis. Water sources are different, which means the feed water contains other materials and contaminants depending on the type of water. The analysis data of the water is used to determine the type of pretreatment required in a particular reverse osmosis system. The pretreatment is also determined by the location of the water supply since water supplies vary with locations. In most cases, the reverse osmosis system requires a water softener or an antiscalant to prevent the distraction of the membrane.

A detailed chemical analysis of feed water involves measuring the hardness of the water. The components causing water hardness include calcium, magnesium, barium, chlorine, and PH. The water analysis does not always forecast the chances of the distraction of reverse osmosis parts. The membrane manufacturers have come up with computer programs that make water analysis easy and fast.

Does Feed Water Need to be Softened by the Reverse Osmosis?

One way of reducing the ability of mineral accumulation upstream of the membrane is the ion exchange. Ion exchange uses sodium to soften water by removing other metals such as calcium, magnesium, and barium prevention the damage of the reverse osmosis membrane. Sodium forms soluble salts which do not pass through the membrane and do not form mineral scales upstream of the membrane. The sodium minerals rejected by the membrane are later removed using sodium chloride brine and dumped somewhere. Therefore, ion exchange that brings about water softening is highly recommended for water that has a high content of metals.

What Is the Lifespan of a Reverse Osmosis System?

The period at which your reverse osmosis system will depend on your way of care and maintenance. To ensure your system lasts longer, you require the following:

  1. It is often changing and replacing the parts that have worn out or are in bad condition, like the storage tanks and the pumps.
  2. You should check your system regularly to ensure it does not run at fault.
  3. It would be best if you changed filters regularly to ensure they do not block.
  4. Ensure your system is under regular maintenance.

You can also contact the maintenance and serviceability team to help you in ensuring your system runs smoothly. They also ensure that no parts of the system fail you during operation. That is to tell you that you can enjoy clean and safe water in your comfort while the maintenance team takes care of the rest.

Is Reverse Osmosis Water Safe To Drink?

Reverse osmosis water is the healthiest and the best choice you can make for your family. It is very healthy and spotless. It helps remove or reduce particles and bacteria and dissolved minerals in tap water, making it safer to drink. To add to that, it helps remove hard minerals and strong contaminants that are not easy to detect and can be very dangerous to your body and unhealthy like lead. Reverse osmosis water helps reduce the chances of acquiring some health risks harmful to your body system. Some of these health risks include:

  1. High blood pressure
  2. Low fertility
  3. Skin rashes
  4. Increased carcinogen creation

The taste, smell, the feeling of reverse osmosis water is different. A shower with this water gives new energy to carry out your activities.

Why is Reverse Osmosis better?

Soft water is excellent for cleaning, laundry, and showering. However, depending on the hardness of your water, there are chances that it can have the total dissolved solids, which are responsible for affecting water taste.

There can also be a number of other contaminants in the water that a water softener is not capable of removing. This is because the hard minerals are generally replaced by sodium. As soon as you install the reverse osmosis system, you will start enjoying water that tastes better along with a perfect tea or coffee.

You will get healthy water quickly from the kitchen sink. The reverse osmosis system helps remove all the contaminants, making it one of the best for most homes.


Reverse osmosis systems are commonly installed under the kitchen sinks or the basements. These systems are essential as they help to clean water for our use. Not only do you get access to healthy water, but you can also wash your cars or use this water for a number of purposes to get spot-free finishes. Now that you know how a reverse osmosis water system works install a reverse osmosis water system that ensures you are safe and free from all the harmful contaminants that can lead to deadly diseases.


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