What is the working principle of reverse osmosis water treatment equipment? How to remove dissolved salts from water?

In industrial pure water preparation, commercial water purification, sewage treatment, boiler feedwater, and advanced treatment of drinking water scenarios,Reverse osmosis water treatment equipmentIt is a widely used core water purification equipment. Many users want to understand the basic operating logic of reverse osmosis equipment during the selection and operation learning process, especially curious about how the equipment can accurately remove dissolved salts in water that are invisible to the naked eye and achieve water purification. This article provides a simple explanation of the complete working principle of reverse osmosis water treatment equipment, detailing the removal process of dissolved salts, and helping industry practitioners quickly understand the core logic of reverse osmosis water purification.

1、 The fundamental core principles of reverse osmosis technology

To understand the working logic of reverse osmosis water treatment equipment, it is necessary to first understand the difference between natural osmosis and reverse osmosis. In a natural state, when two different concentrations of aqueous solutions are separated by a semi permeable membrane, low concentration water will spontaneously permeate into high concentration water, achieving concentration equilibrium. This is a common phenomenon of permeation.

Reverse osmosis is a reverse operation technology based on natural infiltration. By applying external pressure and breaking through the natural osmotic pressure of the water body, water molecules in high concentration water can reverse through the semi permeable membrane, while various impurities in the water are intercepted by the membrane body, achieving the separation of water and impurities. The entire process does not require the addition of chemical agents and belongs to the pure physical filtration and purification method. It is also the core foundation of reverse osmosis equipment for water purification and desalination.

2、 Filtration characteristics of reverse osmosis membrane (desalination core carrier)

The core filtering element of reverse osmosis equipment is the reverse osmosis membrane, which is an artificially synthesized semi permeable membrane with high-precision screening performance. This membrane only allows water molecules to pass through, effectively intercepting the majority of impurities in water, and is also a key component for removing dissolved salts in water.

Different from primary filtration consumables such as quartz sand and activated carbon, reverse osmosis membranes have high filtration accuracy and can intercept small substances that cannot be removed by conventional filtration, including dissolved salt ions, heavy metal ions, bacteria, viruses, colloids, organic matter and other small impurities in water. This is also the core reason why reverse osmosis equipment can achieve desalination and purification of water quality.

3、 Complete workflow of reverse osmosis water treatment equipment

Reverse osmosis equipment is not a single membrane filtration, but a complete process of pre-treatment system+filtration+reverse osmosis host filtration to ensure stable and compliant water quality, while protecting reverse osmosis membrane components and extending equipment service life.

1. Raw water pretreatment stage

The raw water first enters the pretreatment system and is filtered through multi-media filters, activated carbon filters, filters, and other devices to intercept impurities such as sediment, rust, suspended solids, macromolecular colloids, and residual chlorine in the water in advance. This step can effectively prevent large particle impurities from scratching and blocking the reverse osmosis membrane, laying the foundation for subsequent deep desalination filtration and ensuring stable operation of the equipment.

2. High pressure pressurization stage

The pre treated clean water is pressurized by a high-pressure pump to provide power for reverse osmosis filtration. According to different water quality concentrations, the equipment adjusts the adaptive pressure to overcome the natural osmotic pressure of the water body, meet the operating conditions of reverse osmosis and reverse filtration, and enable water molecules to have the power to penetrate the reverse osmosis membrane.

3. Membrane element deep filtration and diversion stage

The pressurized water enters the interior of the reverse osmosis membrane shell for physical screening and filtration. When water flows through the membrane, pure water molecules penetrate the membrane layer and form standard pure water; Dissolved salts, heavy metals, organic matter and other impurities in water cannot pass through the membrane and are discharged with the remaining water flow, forming concentrated wastewater and achieving automatic separation of pure water and wastewater.

4. Water quality stabilization and effluent stage

The filtered pure water is transported to a pure water tank for storage after being stabilized and tested for water quality through pipelines. It can be directly used for industrial production, domestic water, process water replenishment, and other scenarios; Concentrated wastewater is uniformly discharged or recycled through pipelines, and the entire operation process can be continuously circulated.

4、 Detailed mechanism of reverse osmosis equipment for removing dissolved salts from water

The dissolved salts in water are the main cause of high water hardness, excessive conductivity, and severe scaling. These salts dissolve uniformly in the form of ions in water and cannot be observed by the naked eye. Conventional filtration and boiling methods cannot remove them, and high-precision reverse osmosis technology can only be relied on for screening.

1. Principle of particle size screening interception

The molecular diameter of water molecules is much smaller than the diameter of various dissolved salt ions. Reverse osmosis membranes have a dense microporous structure, with pore size accurately controlled within a range that only allows water molecules to pass through. Cations such as calcium, magnesium, sodium, and potassium in water, as well as anions such as sulfate, chloride, and bicarbonate ions, are all water-soluble salt ions with particle sizes larger than the membrane pore diameter. They cannot penetrate the reverse osmosis membrane and are completely trapped on the membrane surface.

2. High pressure driven forced desalination

Under the pressure drive of the high-pressure pump, the water continuously washes the membrane surface, and pure water molecules continuously permeate to form pure water. The intercepted salt ions cannot accumulate and remain, and will be discharged from the equipment along with the concentrated water flowing at high speed, avoiding salt adhesion to the membrane surface and causing scaling and blockage. The continuous water flow erosion ensures the stability of the desalination effect of the equipment.

3. Physical desalination without chemical reaction

The entire desalination process is purely physical screening, without changing the structure of water molecules or adding chemical reagents such as softening agents and flocculation agents. It relies on the accuracy of membrane screening to achieve saltwater diversion. The desalination process is safe and stable, without secondary pollution, the effluent quality is uniform, and the desalination rate is stable and controllable.

5、 Desalination effect and water quality advantages of reverse osmosis equipment

Under normal operating conditions, reverse osmosis water treatment equipment can stably remove the vast majority of dissolved salt substances in water, effectively reduce water conductivity and hardness, and solve problems such as water scaling, water hardness, and excessive salt content. Pure water treated with reverse osmosis is suitable for industrial production, food processing, boiler water replenishment, medical pure water, civilian clean water and other scenarios that require water quality purity.

At the same time, the entire set of equipment has a high degree of automation, which can achieve continuous water production, automatic flushing, and automatic diversion, with convenient operation and maintenance. It is currently the mainstream equipment for desalination and water quality purification of water bodies, widely applicable to various water treatment engineering scenarios.

Summary

Reverse osmosis water treatment equipmentRelying on the principle of high-pressure reverse osmosis and high-precision reverse osmosis membrane physical screening to achieve desalination of clean water. By preprocessing and filtering impurities, providing permeation power under high pressure, and accurately screening the membrane, only pure water molecules are retained, and all dissolved salts, colloids, heavy metals, and other impurities in the water are intercepted to achieve saltwater separation. With the characteristics of pure physical filtration, stable desalination effect, simple operation and maintenance, and wide adaptability, reverse osmosis water treatment equipment has become the core equipment for industrial pure water preparation and deep desalination of water quality.