When the reverse osmosis membrane element is confirmed to be contaminated, or before a long-term shutdown, or as a regular routine maintenance, it is recommended to clean the membrane element.

After a period of normal operation, the reverse osmosis membrane element will be contaminated by suspended matter or insoluble salts that may exist in the feed water. Common contaminants include calcium carbonate precipitation, calcium sulfate precipitation, metal (iron, manganese, copper, nickel, aluminum, etc.) oxide precipitation, silicon sediment, inorganic or organic sediment mixture, NOM organic matter, synthetic organic matter (such as: scale inhibitor/dispersant, cationic polyelectrolyte), microorganisms (algae, mold, fungi), etc.

Reverse Osmosis Membrane Element ULP-8040

The nature and speed of contamination depend on various factors, such as feed water quality and system recovery rate. Usually contamination develops gradually. If it is not controlled as soon as possible, the contamination will damage the membrane element in a relatively short time. The cleaning cycle of the contaminated reverse osmosis membrane depends on the actual situation on site. The normal cleaning cycle is once every 3-12 months. The steps for cleaning reverse osmosis membrane elements are as follows: 　　 　　

1. Pump clean, free chlorine-free, anti-contamination reverse osmosis product water from the cleaning tank (or corresponding water source) into a pressure vessel and drain for a few minutes.

2. Prepare the cleaning solution in the cleaning tank with clean product water.

3. Circulate the cleaning solution in the pressure vessel for 1 hour or a pre-set time.

4. After cleaning is completed, drain and rinse the cleaning tank, and then fill the cleaning tank with clean product water for the next rinse.

5. Pump clean, free chlorine-free product water from the cleaning tank (or corresponding water source) into a pressure vessel and drain for a few minutes.

6. After flushing the reverse osmosis membrane system, operate the reverse osmosis system with the product water discharge valve open until the product water is clean and free of foam or detergent, usually 15-30 minutes.