MODERATE SOLIDS CONTENT.
Bacteria removal main task.
For example, for a "regulated" water supply, where the primary function of the membrane system is to reject bacteria, and some suspended solids.
Concentration of suspended solids and microorganisms will build up in the membrane tank, so that some waste water must be released from the tank from time to time. The frequency is obviously dependent on the quality of incoming raw water.
Level control.
The break tank is large enough to fit a ball float valve, or a float switch with differential to avoid excessive on/off pump operation.
High peak inflow scenario
If raw water arrives as a large quantity, such as the rinse water in a dairy recycling system, then an additional tank should be provided to hold this quantity during the period that it will take to treat the water.
Dosing for solids.
A similar arrangement could used if alum or another chemical is to be used to precipitate suspended solids, or flocculate organics prior to membrane. In which case the tank must be large enough to provide sufficient time, and arranged to prevent carryover of solids into the membrane tank.
100e overview
Installation options