Why is the flow rate of water from the MBR not constant?
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For the MBR unit, an Eleyro metering pump is used for suction, and a vacuum gauge is installed between the membrane fibers and the pump. The idea was to observe the changes in pressure when the flow rate of the water output remains constant at 1 L/h. However, in practice, the film contamination on the membrane fibers at the front becomes increasingly severe, and the pressure (negative pressure) rises as well. Yet the flow rate of the water output decreases as the pressure increases. What is going on? Shouldn’t a metering pump be used instead of an MBR suction pump? Does this happen with all suction pumps? I need some guidance.
Using a metering pump is not a problem, but it is somewhat wasteful of resources and fails to provide accurate measurement, as the MBR membrane represents a variable that cannot be kept constant.
The water flux of MBR membranes is a dynamic variable; as usage time increases, the membrane flux decreases. The output water from the membrane is regulated by adjusting the valve at the outlet of the extraction pump; if the amount of water extracted does not meet the requirements, the membrane must be cleaned before it can be put back into use.
What was said upstairs makes sense; the water flux of MBR membranes is a non-constant variable as usage time increases.