The flux of the MBR membrane will decrease after a certain period of time, which will affect the filtration results, the final water production, and the quality of produced water. Therefore, it is necessary to clean the MBR membrane system regularly. The following article will share the knowledge about the backwashing of the MBR membrane Reactor.
What is Backwashing?
Backwashing of MBR membrane bioreactor is the process of cleaning the filtered permeate from the inside of the membrane fiber (outlet side) to the outside of the membrane fiber (inlet side) under certain pressure, using the clean water that has been filtered to clean the pollutants inside the membrane fibers.
How Often To Backwash MBR Membrane Reactor?
Usually, we recommend that our customers carry out backwashing work once a week. In the case that the backwashing effect is not very effective, we recommend recovery cleaning, as well as offline cleaning. Under normal circumstances, recovery cleaning is performed every three months, and offline cleaning is performed after three months, usually once a year or half a year, depending on the situation.
What are the cleaning Methods of MBR Membrane Bioreactor?
We can wash the MBR membrane repeatedly to ensure the filtration effect. Common Hollow Fiber MBR membranes have the following cleaning methods. We can perform combined cleaning according to the degree of membrane pollution.
Air Diffuser Cleaning: The MBR membrane is flushed by compressed air to cause the membrane fibers’ vibration, so the contamination particles are peeled off to achieve the purpose of cleaning. It is generally used to clean larger particulate matter such as sludge.
Backwash Cleaning: Filtered water is pumped from the backwash tank to the MBR membrane pumping pipe to clean the impurities in the membrane pores. Generally, it needs to be cleaned regularly every day.
Chemical Backwash Cleaning: Add the chemical cleaning agent to clean the MBR membrane, which is generally used to clean insoluble substances. The optional solutions are 1000PPM effective sodium hypochlorite solution, MBR membrane cleaning agent (MOL), etc. The cleaning dosage: 2L/m2 membrane area + backwash pipe volume.
Chemical Offline Cleaning: After the MBR membrane has been used for a long time, the filtration performance cannot be recovered by the above mentioned cleaning methods. At this time, the MBR membrane bioreactor needs to be immersed in a special chemical solution (such as oxalic acid or sodium bisulfite) for 30-60 minutes to clean the microorganisms and inorganic salt structure grease and other substances of the MBR membrane.
The above is the answer to the question of how often we should backwash the MBR membrane bioreactor and introduce related cleaning methods. The cleaning of the MBR membrane bioreactor is a complicated and careful process, and it is recommended to seek professional and technical personnel to assist in cleaning.