Why did the output of the reverse osmosis equipment suddenly decrease?

Many users may have encountered a sudden decrease in the water output of their reverse osmosis equipment. To quickly determine the cause, you first need to confirm the service life of the reverse osmosis membrane. Generally, the service life of a reverse osmosis membrane is around one and a half to two years, but this is not absolute, as the service life of the reverse osmosis membrane depends on the quality of the raw water and the effectiveness of the pretreatment system. Therefore, a sudden reduction in the water output of the reverse osmosis equipment is not solely due to a problem with one particular component. To determine the exact cause, you need to consider the following aspects.

1. Reduced number of membrane modules:

Solution: Operate with the designed number of membrane modules.

2. Low-pressure operation:

Solution: Operate at the designed base pressure.

3. Membrane module compaction:

Solution: Membrane module compaction occurs when operating at pressures significantly exceeding the base pressure. The membrane module must be replaced.

4. Reduced operating temperature:

Solution: Operate at the design temperature. 25ºC operation

5. Operation at a high recovery rate:

Solution: When operating at a recovery rate above 75%, the amount of concentrate water decreases, increasing the concentration factor of the water in the membrane module, resulting in a significant deterioration of the feed water quality. Due to the increase in osmotic pressure of this feed water, the permeate water volume decreases. In severe cases, salt scaling will precipitate on the membrane surface. Water production must be at the design recovery rate.

6. Metal oxides and impurities adhere to the membrane surface:

Solution: Perform low-pressure flushing daily.

7. Increase in pressure difference in the reverse osmosis unit during operation:

Solution: Improve the operation and management of the pretreatment unit, improve the quality of water entering the reverse osmosis unit, and use chemicals to clean the membrane modules.

The above methods are used to determine the causes of a sudden decrease in the water output of reverse osmosis equipment. Hopefully, this will be helpful in troubleshooting such issues in the future.