Reverse osmosis water purifier RO membrane failure phenomenon, it is important to understand the principle of common problems with answers

Reverse osmosis water purifier RO membrane failure phenomenon, it is important to understand the principle of common problems with answers

Reverse osmosis water purifier as a modern family and industrial water treatment of important equipment, its core components RO membrane in the long-term use of the process may appear a variety of failures. The following will provide you with a detailed introduction to reverse osmosis water purifier RO membrane knowledge, common failure reactions and solutions.

The working principle of RO membrane
Reverse osmosis is a membrane separation operation that separates a solvent from a solution using a pressure difference as the driving force. In the natural osmosis process, the solvent (e.g., water) will spontaneously diffuse from a low-concentration solution to a high-concentration solution until it reaches osmotic equilibrium. Reverse osmosis is higher than the osmotic pressure of the solution under the action of the membrane side of the pressure, so that the solvent to the opposite direction of permeation, so as to achieve the separation of solutes and solvents.RO membrane pore size is very small, usually only 0.0001 microns or so, and can effectively retain most of the inorganic salts, dissolved organics, dissolved solids, organisms, and colloids and other impurities, and only allow water molecules and a small number of small molecules through.

Scenarios for RO membranes
Family drinking water treatment: can significantly improve the quality of tap water, remove residual chlorine, heavy metals, organic matter and other pollutants, to provide residents with safe, pure drinking water.
Industrial production of water: It plays an important role in water treatment in electronics, pharmaceutical, chemical, food and other industries. It can prepare high-purity water for precision manufacturing, laboratories, cooling systems, boiler water supply, etc., to ensure the stability of the production process linea and product quality.
Desalination: In coastal and island areas, RO membrane system can convert seawater into fresh water to meet the needs of agricultural irrigation, industrial production and residential drinking water, especially in water-scarce areas of great significance.
Food and beverage industry: used in the production of beverages, beer, liquor, health products and other products, water purification, as well as food processing water treatment, to protect the quality of product health and taste.

RO membrane failure response
Decrease in water production: This is one of the most common failure reactions of RO membrane. It may be due to the membrane surface is polluted, such as metal oxides, dirt and other attached to the membrane surface caused by clogging, but also may be the inlet water conductivity increases, membrane module pressure density, the working pressure does not reach the rated value and other reasons.
Decrease in desalination rate: manifested as an increase in the conductivity of produced water. It may be caused by RO membrane contamination, degradation in contact with strong oxidizer, O-ring damage or leakage.
Abnormally high inlet pressure: it may be caused by pretreatment equipment failure, pressure regulator malfunction, pipeline or valve clogging and so on. Excessive inlet water pressure may cause damage to the system.
Leakage problem: Leakage may occur in the connectors, seals, high pressure pumps and other parts of the RO system. This not only leads to water waste, but also may affect the normal operation of the equipment.
Water quality problem: The quality of produced water does not meet the requirements and may contain too much dissolved matter or ions. This may be caused by membrane contamination, poor pretreatment, improper pH control, etc.
Noise and vibration: RO system produces noise and vibration during operation, which may be caused by damaged bearings and impellers of high-pressure pumps, irrational pipeline support structure and other reasons.

RO Membrane Frequently Asked Questions and Answers
Q: How often does the RO membrane need to be replaced?
A: In general, the service life of the reverse osmosis membrane is 2-3 years, but the specific replacement time should be determined according to the raw water quality, frequency of use and maintenance and other factors.


Q: How to determine whether the RO membrane needs to be cleaned?
A: RO membrane may need to be cleaned when the water production drops, desalination rate decreases, inlet water pressure rises, differential pressure increases, etc.


Q: Can I use tap water to flush the RO membrane directly?
A: No. Tap water contains impurities and bacteria, direct flushing may lead to membrane contamination, you should use pre-treated water for flushing.


Q: Can RO membrane be cleaned with chemicals?
A: Yes, but you need to choose the right chemicals and cleaning methods. Different contaminants require the use of different cleaning agents, such as acidic cleaning agent for the removal of metal oxides, alkaline cleaning agent for the removal of organic matter.


Q: RO membrane in the use of what matters needing attention?
A: We should pay attention to the feed water quality to meet the requirements, to avoid membrane contamination and damage; regularly check the operating parameters of the equipment, such as pressure, flow rate, conductivity, etc.; in accordance with the prescribed operating procedures for the start, stop and maintenance of the equipment and so on.


Q: What is the reason that the water production drops but the desalination rate is normal?
A: It may be caused by contamination of membrane surface, insufficient water intake, insufficient working pressure, lower water temperature, etc.    

Q: What is the reason that the desalination rate decreases but the water production rate is normal?
A: It may be caused by RO membrane being polluted, oxidized in contact with strong oxidant, damaged O-ring or leakage.


Q: Will the water yield of RO membrane drop in winter?
A: Yes. The rated water production of RO membrane is designed based on 25℃, and the water production will drop 2-3% for every 1℃ decrease in temperature.

Q: How to prevent RO membrane scaling?
A: RO membrane fouling can be prevented by controlling the hardness of incoming water, adding scale inhibitors, and regular cleaning.

Q: RO membrane can be contaminated after the recovery?
A: If the pollution is not serious, through the correct cleaning method can restore the membrane's linea performance; but if the pollution is serious, you may need to replace the RO membrane.

Q: Why is the RO membrane water odor?
A: may be the raw water has a bad smell, poor pretreatment, RO membrane contamination and other reasons. You can check the quality of raw water, cleaning pretreatment equipment and RO membrane.