Reverse Osmosis (RO) systems are a water filtration technology that removes pollutants and impurities from water, primarily through a semi-permeable membrane. The process works by applying pressure to the water, forcing clean water through while leaving behind dissolved salts, chemicals, and other impurities.

Reverse osmosis systems are widely used in homes and industries to provide high-quality drinking water. However, a common problem with these systems is the amount of wastewater they produce. In this article, we'll explore how RO systems work, their benefits, and ways to reduce the amount of water wasted during the filtration process.

What is reverse osmosis?

What is reverse osmosis system? It's a water treatment technology that filters tiny and dissolved solids from water through a semi-permeable membrane.

In this process, water is forced to pass through a fine filter membrane that only allows water molecules to pass through, while larger molecules and deadly ones (such as salt, bacteria, and chemicals) are intercepted upstream of the membrane, resulting in purified water.

Advantages of RO system

• Efficient purification: RO systems can efficiently remove bacteria, viruses, heavy metals (such as lead, and mercury), organic compounds, and other dissolved solids in water to provide pure drinking water.
• Improved taste: By removing impurities from water, RO systems can significantly improve the taste and odor of water, making it fresher and more delicious.
• Energy saving and environmental protection: Compared with other water treatment technologies, RO systems usually do not require the use of high energy or chemicals, and are more environmentally friendly.
• Easy maintenance: Modern RO systems are simple in design and relatively easy to maintain, requiring only regular replacement of filter cartridges.

Disadvantages of RO system

• Water consumption problem: During the filtration process, RO systems produce wastewater, which is water used to flush pollutants. This part of the water is usually unusable, increasing the waste of water resources.
• Slow filtration: The RO system has a relatively slow filtration speed and may not be suitable for situations where a large amount of clean water is needed immediately.
• Higher cost: Compared with general filtration systems, the purchase and operation costs of RO systems are higher, and the filter element needs to be replaced regularly.
• May remove beneficial minerals: RO systems may also remove some beneficial minerals in the water, such as calcium and magnesium.

How does reverse osmosis work?

Reverse osmosis works by using high pressure to push water through a fine semi-permeable membrane that blocks large molecules and impurities (such as salt, bacteria, and chemicals) while allowing only water molecules to pass through.

In this process, pure water is separated from the water, while impurities remain on the other side of the membrane, thereby purifying the water. This technology not only effectively removes impurities, but also reduces the total amount of dissolved solids in water. It is widely used in drinking water purification and wastewater treatment.

What pretreatment is required for a RO system?

• Sedimentation and filtration: Remove suspended particles and larger contaminants from the water to prevent them from clogging the reverse osmosis membrane.
• Activated carbon filtration: Used to remove chlorine and organic chemicals from the water, as these substances may damage the reverse osmosis membrane.
• Softening treatment: If the water hardness is high, softening treatment may be required to remove calcium and magnesium ions from the water to prevent the reverse osmosis membrane from reducing efficiency due to scaling.
• Antimicrobial treatment: Sometimes antimicrobial treatment of the incoming water is also included to prevent microbial growth.

These pretreatment steps help optimize the reverse osmosis process, improve the system's filtration efficiency, and extend the life of the equipment.

Recommended RO system

The Tokit AkuaPure T1 reverse osmosis water filter has an advanced 9-stage filtration function that can remove 99.9% of more than 1,000 contaminants and a filtration accuracy of 0.0001 microns, which can effectively eliminate TDS, bacteria, and odors.

It does not remove minerals that are beneficial to humans like other water purifiers and also uses a strontium-rich filter to improve water quality, which is good for health and tastes better. You can easily enjoy refreshing, strontium-rich water at home, which can improve bone density and enhance immune function.

In addition, this plug-and-play device does not require installation and comes with a smart control display for easy operation. It comes with two 1.6-liter kettles for easy use, and the current pre-sale price is $249.99, which is lower than the regular $399.99.

How to reduce wastewater in the RO system?

• Use high-efficiency RO membrane: Selecting a reverse osmosis membrane with high water flux and low wastewater rate can reduce the generation of wastewater. Some high-efficiency membranes can reduce the ratio of wastewater to clean water to 1:1 or even lower.
• Install wastewater recovery system: Some RO systems provide a wastewater recovery function, which sends wastewater back to the system through a recirculation pump for re-filtration, thereby reducing the amount of wastewater.
• Adjust water pressure: The operating efficiency of the RO system is closely related to water pressure. Increasing water pressure can enhance permeation efficiency and reduce wastewater discharge. Generally, 60 psi is a more ideal water pressure value.
• Optimize system design: Selecting appropriate pre-filters, pressure regulators, and water storage tanks can improve the overall efficiency of the RO system and reduce wastewater.
• Reasonable maintenance: Regularly replacing filters and membranes to keep the system in good operating condition will help improve water purification efficiency and reduce wastewater generation.

By combining the above methods, wastewater in the RO system can be effectively reduced and water resource utilization can be improved.

Summary

Reverse Osmosis (RO) systems provide a convenient and effective solution for filtering impurities from water, ensuring cleaner, safer drinking water for your home or business.

While the system is highly efficient, it does produce some wastewater, which can be minimized through various methods, such as using high-efficiency membranes and proper system maintenance.

For more home or kitchen appliances, you can browse the official website of TOKIT, which not only offers countertop water purification systems but also smart induction cookers and cooking robots for you to purchase.

FAQ

Does a RO system need a booster pump?

Reverse osmosis systems often require a booster pump, especially when the inlet water pressure is low. The role of the booster pump is to increase the water pressure to ensure that there is enough pressure to push the water through the reverse osmosis membrane, thereby improving filtration efficiency.

Without sufficient water pressure, the water output of the system may be reduced and the filtration effect will also be affected. Typically, the inlet water pressure needs to reach 40-100 psi, and the booster pump can help ensure that the system works properly under low-pressure conditions.

Does a reverse osmosis system need an osmotic pump?

A reverse osmosis system does not necessarily require an osmotic pump, but it can improve efficiency in certain situations. The main function of an osmotic pump is to reduce the amount of wastewater in the system and improve water utilization, especially for gravity-driven reverse osmosis systems.

An osmotic pump reduces pressure loss and reduces energy consumption by using the pressure of wastewater to drive the filtration process. If you want to reduce wastewater discharge and improve overall efficiency, installing an osmotic pump is a good choice, but not all systems require it.

How to prevent biofouling in reverse osmosis systems?

The following measures can be taken to prevent biofouling in reverse osmosis systems:

• Regular disinfection: Use appropriate disinfectants to clean the system to prevent the growth of microorganisms.
• Pretreatment filtration: Install an efficient pretreatment system, such as activated carbon filtration or ultraviolet germicidal lamps, to reduce the amount of microorganisms entering the system.
• Keep the system sealed: Ensure the sealing of pipes and components to prevent external contaminants from entering the system.
• Control water temperature and flow rate: Properly control water temperature and flow rate to reduce environmental conditions for microbial growth.

These steps help prevent biofouling of reverse osmosis membranes.

Why do you need RO tanks?

The main function of RO tanks (reverse osmosis tanks) in reverse osmosis water treatment systems is to store filtered water. This tank can provide pure water immediately when the user needs it, avoiding waiting for the filtration process to complete each time water is needed.

In addition, the tank helps maintain system pressure and ensures that the water flow is steadily delivered throughout the system, improving the efficiency and convenience of the water treatment system.

Does reverse osmosis waste water?

Yes, reverse osmosis systems do produce a certain amount of wastewater in the process of filtering water. This is because the system needs to use part of the water to flush the membrane surface to remove the intercepted pollutants and prevent the membrane from clogging.

This part of water usually contains high concentrations of impurities and salts and cannot be used directly. However, this wastewater can be used for other purposes, such as flushing toilets, watering flowers, or other scenarios that do not require pure water, thereby reducing the overall waste of water resources.

Related reading: How to purify water at home?