How to wash RO membrane

Washing the RO membrane is necessary for RO systems that are already operating. Cleaning the RO membrane is not too difficult, but the practitioner needs to clearly understand the RO system and some principles before doing it.

Why is it necessary to wash the RO membrane?

• The system’s performance decreases after a period of operation due to adhesion and deposition of metal ions, metal oxides, inorganic substances, colloids, microorganisms, and organic compounds.
• Avoid the risk of clogging that reduces the life of the RO membrane

When do you need to clean the RO membrane?

• Pressure difference of 15% or more.
• Traffic drops by 10% or more.

Cause of RO membrane blockage

• Suspended residue does not dissolve
• Inorganic residue
• Organic residue
• Iron and aluminum metal oxide or hydroxide deposits.
• Microbiological Residue

Prepare before cleaning the RO membrane

• Preliminarily check the valves and RO pipes to ensure they are tight and open and close easily.
• Add water to the RO system, fully open the drain valve and close the clean water outlet valve.
• Check for any leaks, if so, replace immediately.
• Pump clean water into the system and discharge it along the “drain” line of the system.
• Microbial cleaning chemicals and RO descaling chemicals

RO membrane cleaning process

Microbiological Cleaning

• Pump water into RO and 300L tank
• Mix RO membrane biodegradation chemicals, maintain pH around 10-11
• Turn on the pump to circulate into the RO system for about 5 minutes so that the chemicals are evenly absorbed into the membrane.
• Turn off the circulation pump to soak for 30 minutes
• Completely remove the amount of chemicals soaked into the RO system, then use clean water to push the dirty substances out.
• Continue the 2nd and 3rd times like the 1st time.

Descale RO membrane

• RO water pump and 300L tank
• Mix RO membrane descaling chemicals, measure pH  2-3
• Turn on the circulation pump into the RO system for about 5 minutes so that the chemicals are evenly absorbed into the membrane
• Turn off the circulation pump to soak for 30 minutes
• Completely remove the amount of chemicals soaked into the RO system, then use clean water to push the dirty substances out.
• Continue the 2nd and 3rd times like the first time until the residue is clean

Finish the RO membrane washing process

• Use RO pump to run the system, drain all flow within 30 minutes, adjust high and low pressure differently.
• Adjust the clean water intake flow and discharge flow according to the correct capacity of the RO system.
• Take RO water samples to check quality, hand over the RO system to the factory to start operating again.

Nam Viet ETC Company specializes in installing, maintaining, and cleaning industrial RO systems. Please contact us for advice and support.

Hotline 0932562177