Reverse Osmosis VS Nanofiltration Systems-What is the Difference


Are you trying to decide whether a RO or NF system is the right choice for your water filtration needs? With so many options on the market, it can be difficult to know which one will give you the most bang for your buck.

However, when placed side-by-side and compared against each other, there are clear differences between these two water filtration systems. In this post, we’ll examine those differences in detail and help you make an informed decision about which type of system best meets your specific requirements.

Reverse Osmosis Systems

Reverse osmosis (RO) systems are a common membrane treatment system. The working principle is a water filtration system that uses a semi-permeable membrane to remove ions, molecules, and larger particles from water. The process is called reverse osmosis because it uses pressure to force water molecules through a membrane, which is the opposite of the natural process of osmosis.

Reverse osmosis systems are commonly used in commercial or industrial water purification to remove impurities and soluble substances from raw water.

Reverse Osmosis Systems

Pros of Reverse Osmosis Systems

As reverse osmosis technology has matured, more and more reverse osmosis filtration units are becoming popular in residential, industrial, and commercial applications. This is chiefly because they offer numerous advantages over other water treatment systems.

● Highly Effective

One of the biggest advantages of using reverse osmosis systems is that these units are highly effective at removing contaminants in the raw water. Because the water is forced through a fine RO membrane, most impurities are unable to pass through and are removed from the water. This means that the water produced by an RO system is typically much purer than water from other sources, such as a tap or a well.

RO membrane

● Relatively Low Maintenance

Another significant advantage of reverse osmosis machines is their relatively low maintenance costs. The service life of the reverse osmosis membrane in the RO system is usually around 2-3 years, depending on the quality of the incoming water and the quality of the reverse osmosis membrane.

● Compact Designs

In addition to the benefits of efficiency and low maintenance, reverse osmosis systems are relatively compact in design. This makes them well-suited for use in a variety of settings, including small homes and apartments. Because they do not require a lot of space, they can be easily installed in a variety of locations, such as under a sink or in a basement.

● Affordable

Another advantage of reverse osmosis equipment is that they are relatively affordable. While the initial cost of purchasing and installing an RO system can be somewhat high, the ongoing cost of operating the system is relatively low. This is because the filters in an RO system are relatively inexpensive and do not need to be replaced very often. In addition, reverse osmosis systems typically produce higher quality water than other sources and can be used to obtain pure/drinking water saving the expense of bottled water or other expensive water sources.

Nanofiltration Systems

Nanofiltration, like reverse osmosis, is a membrane filtration process. The pores of nanofiltration membranes are small enough to trap a wide variety of contaminants, including bacteria, viruses, and other harmful particles, outside the membrane. Therefore the device can be used to remove dissolved organic and inorganic compounds from raw water.

Nanofiltration systems usually consist of a pressure vessel, a membrane, and a series of pumps and valves used to control the flow of water through the membrane. It can be combined with other water treatment processes to achieve different water treatment effects.

Figure 2 Nanofiltration system.

Pros of Nanofiltration Systems

There are several advantages of using nanofiltration systems in water treatment, including their ability to remove a wide range of contaminants, their relatively low cost, and their ease of use.

● Diverse Contaminant Removal Range

One of the main advantages of nanofiltration systems is that they can effectively remove a wide variety of pollutants from water at a low cost. These systems are able to remove divalent ions, dissolved salts, bacteria, and other impurities from water, making them safe for distinct uses. In addition, nanofiltration systems are able to remove many types of organic contaminants, such as pesticides and herbicides, which can be harmful to human health if ingested.

● Relatively Low Cost

Another advantage of nanofiltration systems is their relatively low cost. Nanofiltration systems are generally less expensive to install and operate than other filtration methods such as reverse osmosis. This makes them an attractive option for water treatment facilities, particularly in areas where the cost of water treatment is a major concern.

Figure 3 Nanofiltration.

● Easy to Use

In addition to their cost-effectiveness, nanofiltration systems are also easy to use. These systems typically require minimal maintenance and can be operated by trained personnel with little experience. This makes them a good choice for water treatment facilities that need to quickly and efficiently filter large volumes of water.

● High Flux Rate

The flux rate in a nanofiltration system refers to the amount of water that is able to pass through the membrane per unit of time. A high flux rate would indicate that a large amount of water is able to pass through the membrane in a given period of time, which can be beneficial for applications that require large volumes of water to be treated.

nanofiltration system membrane

Differences Between RO Systems and NF Systems

RO and nf are two similar water treatment processes that are used to purify water. Both processes use pressure to force water through a membrane, but there are some key differences between the two.

● Membrane Pore Size

One key difference between the two processes is the size of the pores in the membrane. The pores of a reverse osmosis membrane are much smaller than those of a nanofiltration membrane, which means it has a higher filtration accuracy and can remove a wider range of impurities. However, this also means that it is more likely to remove beneficial minerals and other substances from the water. To be precise, reverse osmosis membranes have pores measuring approximately 0.0001 microns while nanofiltration membranes have pores measuring 0.1 to 10 nanometers.

Membrane Pore Size

● Type and Range of Pollutants Removed

Reverse osmosis (RO) and nanofiltration (NF) systems are both types of membrane filtration systems that are used to remove pollutants from water. However, they are designed to remove different types of pollutants. RO systems are designed to remove a wide range of pollutants, including dissolved salts, bacteria, viruses, and other contaminants that have a molecular weight of greater than 200-300 Daltons.

This makes them effective at removing a wide range of pollutants, including many inorganic compounds, as well as some organic compounds. On the other hand, NF systems are designed to remove smaller molecules, with a molecular weight of less than 200-300 Daltons. This makes them effective at removing organic compounds, such as pesticides and herbicides, as well as some inorganic compounds, such as heavy metals.

● Operating Pressure

Another difference between the two processes is the required amount of pressure. Reverse osmosis typically requires more pressure than nanofiltration, which can make it more expensive to operate. However, the higher pressure also makes it more effective at removing impurities. Reverse osmosis (RO) systems typically operate at a pressure of around 50-100 pounds per square inch (psi), while nanofiltration (NF) systems operate at a pressure of approximately 5-30 psi.

Figure 4 Operating pressure.

● Application Fields

Regarding the application of the system, reverse osmosis is often used in seawater desalination plants to efficiently remove salt from seawater to obtain pure water. It is also commonly used in homes and businesses to purify drinking water. On the other hand, nanofiltration is often used in wastewater treatment plants to remove impurities from the water before it is discharged into rivers or streams.

Reverse Osmosis and Nanofiltration Systems, Which is Better?

Reverse Osmosis (RO) systems and nanofiltration (NF) systems are both popular ways of treating water, but it is important to determine which one is best for your needs. Reverse osmosis systems use reverse osmosis membranes with a smaller pore size, resulting in higher filtration accuracy, making them ideal for removing particulates, metals, salts, and other substances.

Nanofiltration systems on the other hand use a semi-permeable membrane that contains tiny pores that are big enough to allow small molecules such as calcium or sodium ions through while trapping larger molecules like bacteria and viruses. Both reverse osmosis (RO) and nanofiltration (NF) systems are effective at removing impurities from water. However, each type of system has its own unique characteristics and benefits, so it’s difficult to say which is “better” overall.

Reverse Osmosis (RO) systems

In general, the best choice between RO and NF systems will depend on the specific needs of your application. If you need to remove a wide range of impurities from water, an RO system may be the better choice. However, if you only need to remove certain types of contaminants, an NF system may be more effective and efficient.


As you can see, there are several advantages to using reverse osmosis and nanofiltration systems in your home or business. Whereas reverse osmosis systems are great at removing particles larger than 2 microns from water, nanofiltration systems are better at removing smaller particles If you’re looking for the best quality water filtration systems on the market, look no further than NEWater.

We offer a wide variety of reverse osmosis and nanofiltration systems that are sure to meet your needs. Contact us today to learn more about our products and how we can help you get the clean, refreshing water you need.



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