RO Membrane: Frontier Analysis of Water Purification Core Technology

In the context of people's increasing attention to water quality safety, RO Membrane, as the "heart" of water purification equipment, is receiving widespread attention. Whether it is household drinking water purification, industrial wastewater treatment, or seawater desalination system, RO Membrane plays a vital role.

What is RO reverse osmosis membrane?

RO membrane (Reverse Osmosis Membrane) is a high-efficiency filtration material made by reverse osmosis technology. It can allow water molecules to pass through the semi-permeable membrane under external pressure, and effectively block impurities such as soluble salts, organic matter, bacteria, viruses and heavy metals in the water.

The pore size of RO membrane is extremely small, usually around 0.0001 microns, and only allows water molecules to pass through. Therefore, it is known as one of the most sophisticated physical filtration methods currently. This technology was first used in NASA's astronaut drinking water purification system, and now it has been widely used in households, industries, agriculture and medical fields.

Core working principle of RO membrane
The core mechanism of RO membrane is reverse osmosis, that is, through external pressure, water molecules in high-concentration solution are reversely permeated to the low-concentration side, leaving impurities. This process relies on a composite membrane with a multi-layer structure. Common structures include:

Polyamide (PA) selection layer: responsible for the main selective filtration.

Porous support layer: provides structural stability.

Polyester non-woven fabric substrate: overall support membrane body.

The entire filtration process is carried out under high pressure (usually 0.4–1.6MPa), and the removal rate of dissolved solids (TDS) in water quality is as high as 95% or more.

Main classification and application fields of RO membrane
Different application scenarios have different performance requirements for RO membranes, so RO membranes are divided into multiple types according to indicators such as flow rate, structure, and pollution resistance.

Household RO membrane
Mainly small and high-efficiency, common specifications are 50G, 75G, 100G, etc. (GPD, indicating daily water production). This type of RO membrane is widely used in water purifiers and pure water machines, with excellent desalination rate and stability.

Commercial and industrial RO membranes

Large flow and high pressure design, commonly used in:

Industrial boiler feed water pretreatment

Ultrapure water system for electronic industry

Food and beverage industry (such as beverage filtration and concentration)

Pharmaceutical water system

Desalination RO membrane

It has stronger corrosion resistance and desalination capacity, can operate at a pressure of up to 6.8MPa, and is widely used in islands, ships and water-scarce areas.

Performance evaluation standards for RO membranes

When selecting high-quality RO membranes, the following core performance indicators need to be considered comprehensively:

Desalination rate: measures the ability of RO membranes to remove dissolved salts from water. The desalination rate of general household RO membranes should be ≥97%, while that of industrial grade membranes can reach 99%.

Flux (water output): determines the water purification speed. The unit is usually L/h or GPD.

Pollution resistance: determines its ability to resist biological pollution and inorganic scaling.

Service life: High-quality RO membranes can be used for 3~5 years, provided that there is a good pretreatment system and regular maintenance.

Chemical stability: must be able to resist a certain concentration of cleaning chemicals.

Common problems and solutions for RO membranes

1. Membrane pollution
Pollution is the main reason for the decline in RO membrane performance, including microbial pollution, organic pollution, inorganic scaling, etc. Solutions include:

Add pretreatment system (such as activated carbon, water softener)

Regularly use professional cleaning agent for backwashing

Control operating pressure and recovery rate to avoid over-concentration

2. Decreased water output
Possible reasons include insufficient inlet pressure, membrane scaling, low temperature, etc. It is recommended to check whether the water pump system and membrane elements are aging.

3. Short service life
The service life is affected by many factors, such as inlet water quality, frequency of use, maintenance, etc. It is recommended to replace the filter element regularly and maintain good operating parameters.

As the core of modern water purification systems, RO reverse osmosis membranes are indispensable in household and industrial applications for their high-efficiency filtration capabilities and wide adaptability. From material innovation to structural optimization, to system integration, RO membrane technology is serving mankind's eternal pursuit of "clean water" with a smarter and more environmentally friendly attitude.