Reverse osmosis equipment is a water treatment device that uses a high-pressure pump to separate water molecules from a solution. It is widely used in industrial, medical, and drinking water applications. The advantages of reverse osmosis equipment are its ability to effectively remove organic matter, inorganic matter, bacteria, viruses, and other impurities from water, improving water quality and quantity. However, reverse osmosis equipment also has a drawback: it cannot be stopped for extended periods, otherwise, it will lead to a decline in equipment performance, or even damage.

So, what should be noted during the shutdown of reverse osmosis equipment? How to properly manage and maintain it? Today, I will share some professional knowledge and experience with you, hoping it will be helpful.

I. Management Methods During Shutdown

Depending on the length of the shutdown, the management methods for reverse osmosis equipment can be divided into the following three categories:

Daily Shutdown (0-48 hours)

Daily shutdown refers to the situation where the reverse osmosis equipment temporarily stops running after normal operation due to certain reasons, generally not exceeding 48 hours. In this case, the management method of the reverse osmosis equipment is relatively simple, mainly including the following steps:

Stop water intake and water production, close the inlet valve, outlet valve, and concentrate valve, keeping the reverse osmosis membrane elements filled with water to prevent the membrane elements from drying out and microbial growth.

Rinse the reverse osmosis system with low-pressure water to remove impurities and concentrate water from the system, preventing membrane element blockage and contamination.

Repeat the above operation every 24 hours to keep the reverse osmosis system clean and moist.

Short-term Shutdown (2-25 days)

Short-term shutdown refers to the situation where the reverse osmosis equipment stops running for a long time after normal operation due to certain reasons, generally between 2 and 25 days. In this case, the management method of the reverse osmosis equipment is more complex, mainly including the following steps:

Stop water intake and water production, close the inlet valve, outlet valve, and concentrate valve, keeping the reverse osmosis membrane elements filled with water to prevent the membrane elements from drying out and microbial growth.

Prepare a 0.5-0.7% formaldehyde solution with reverse osmosis product water, adjusting the pH to 5-6, as a preservative.

Start the cleaning water pump and rinse the reverse osmosis system at a flow rate of 45-58 m3/h, filling the reverse osmosis membrane elements and pipelines with the preservative to prevent the membrane elements from being oxidized and biologically contaminated.

Repeat the above operation every 5 days to keep the reverse osmosis system clean and preserved.

Long-term Shutdown (Over 25 days)

Long-term shutdown refers to the situation where the reverse osmosis equipment stops running for a long time after normal operation due to certain reasons, generally exceeding 25 days. In this case, the management method of the reverse osmosis equipment is more troublesome, mainly including the following steps:

Stop water intake and water production, close the inlet valve, outlet valve, and concentrate valve, keeping the reverse osmosis membrane elements filled with water to prevent the membrane elements from drying out and microbial growth.

Prepare a 0.5-0.7% formaldehyde solution with reverse osmosis product water, adjusting the pH to 5-6, as a preservative.

Start the cleaning water pump and rinse the reverse osmosis system at a flow rate of 45-58 m3/h, filling the reverse osmosis membrane elements and pipelines with the preservative to prevent the membrane elements from being oxidized and biologically contaminated.

Remove the reverse osmosis membrane elements from the pressure vessel, rinse them thoroughly with clean water, place them in a plastic bag, add preservative, seal and store to prevent the membrane elements from being affected by external factors.

Rinse the pressure vessel and pipelines thoroughly with clean water, add preservative, and seal and store to prevent the pressure vessel and pipelines from corrosion and contamination.

II. Precautions During Shutdown

During the shutdown of reverse osmosis equipment, in addition to following the above management methods, the following aspects should also be noted:

When using preservatives, wear protective equipment to avoid contact with skin and eyes, preventing poisoning and irritation.

When using preservatives, pay attention to the expiration date of the preservative. Expired preservatives cannot be used, otherwise, it will affect the preservation effect.

When using preservatives, pay attention to the concentration and pH value of the preservative. Too high or too low concentration and pH value will damage the reverse osmosis membrane elements.

When using preservatives, pay attention to the temperature of the preservative. Too high or too low temperature will affect the stability and activity of the preservative.

When using preservatives, pay attention to the circulation time of the preservative. Too long or too short circulation time will affect the preservation effect.

When using preservatives, pay attention to the storage conditions of the preservative. Avoid direct sunlight and high temperature and humidity to prevent the preservative from deteriorating and becoming ineffective.

When using preservatives, pay attention to the amount of preservative. Follow the instructions, do not overuse or underuse, to prevent waste and insufficiency.

When using preservatives, pay attention to the discharge of preservatives. Follow environmental regulations, do not discharge them arbitrarily, to prevent environmental pollution and ecological damage.

III. Preparation Work Before Restart

During the shutdown of reverse osmosis equipment, if it needs to be restarted, the following preparatory work should be carried out first:

Check all components of the reverse osmosis equipment for damage, looseness, leakage, etc., and replace or repair them in time.

Check the power supply, water source, instruments, and valves of the reverse osmosis equipment to ensure they are working properly, and adjust or replace them in time.

Check the water quality of the reverse osmosis equipment to ensure it meets the requirements of the reverse osmosis membrane elements, and process or replace it in time.

Check the preservative of the reverse osmosis equipment for expiration, deterioration, or ineffectiveness, and replace or dispose of it in time.

Rinse the reverse osmosis system with clean water to completely remove the preservative to prevent the preservative from affecting the reverse osmosis membrane elements and product water.

Prepare a 0.1-0.2% citric acid solution with reverse osmosis product water, adjusting the pH to 3-4, as a cleaning agent.

Start the cleaning water pump and clean the reverse osmosis system at a flow rate of 45-58 m3/h, filling the reverse osmosis membrane elements and pipelines with the cleaning agent to remove scale and deposits from the membrane elements.

Rinse the reverse osmosis system with clean water to completely remove the cleaning agent to prevent the cleaning agent from affecting the reverse osmosis membrane elements and product water.

Restore the normal operation of the reverse osmosis equipment, adjust the operating parameters, and test the operating effect to ensure the performance and quality of the reverse osmosis equipment.

This is my introduction to the management methods and precautions for reverse osmosis equipment during shutdown. I hope it will be helpful to everyone.