Membrane bioreactor (MBR) technology, which combines biological treatment and membrane separation, is increasingly used in wastewater treatment. However, membrane fouling is a common issue that can decrease membrane flux, damage the membrane, and shorten its lifespan. Regular and proper cleaning of MBR membranes is essential to maintain their efficiency and longevity. This guide explains how to clean MBR membranes effectively.

Importance of Cleaning MBR Membranes

Understanding how to clean MBR membranes properly is vital for optimal operation and maintenance.

Inadequate cleaning of MBR membranes can lead to damage and reduced performance. Selecting the right cleaning agent and process is crucial. Typically, acidic solutions are used for inorganic dirt, while alkaline solutions are recommended for microbial or organic pollutants.

Steps for Effective MBR Membrane Cleaning

• Regular Cleaning:
  
  • The frequency of membrane cleaning depends on the negative pressure of the self-priming pump surpassing 0.08 and the water output.
    
• Types of Cleaning:
  
  • Online Cleaning: Performed when the negative pressure is not excessively high, and water output is normal.
  • Offline Cleaning: Conducted when more thorough cleaning is needed.
    
• Online Cleaning Process:
  
  • Drain the Sewage: Empty the membrane tank of sewage.
  • Wash the Membrane: Clean the sludge off the membrane using clean water, repeating the washing and brushing process.
  • Chemical Soak: Soak the membrane in a sodium hypochlorite solution for 30 minutes, followed by air blasting.
  • Rinse: Empty the membrane tank and rinse thoroughly with clean water.
    
• Offline Cleaning Process:
  
  • Disassemble the Membrane: Remove the membrane from the mold shelf.
  • Initial Cleaning: Thoroughly wash the disassembled membrane with water.
  • Chemical Soak: Soak the membrane in a sodium hypochlorite solution for 30 minutes, followed by a 24-hour soak to ensure disinfection.
  • Citric Acid Soak: After rinsing off the sodium hypochlorite solution, soak the membrane in citric acid for 30 minutes.
  • Reinstallation: Once cleaned and soaked, reinstall the membrane onto the mold base.
    
• Cleaning Frequency:
  
  • Online Cleaning: Typically done every 3 months.
  • Offline Cleaning: Generally performed every 6 months.
    

Conclusion

Proper cleaning of MBR membranes involves selecting the appropriate cleaning agents and following a regular cleaning schedule. This ensures the membranes maintain their performance and longevity, providing efficient wastewater treatment.

By adhering to these cleaning guidelines, you can maximize the efficiency and lifespan of your MBR membranes, ensuring reliable and cost-effective wastewater treatment.