Microfiltration (MF):

The microfiltration (MF) is a process mainly used for the separation of submicron size (< 0.1 μm) particulate matter from solution. This process also requires hydrostatic pressure gradient across the membrane and the pressure used is of the order of 100 kPa or so. The pore size of the membranes decides the size of the particulate matter retained. The process is same to ultrafiltration and separation takes place by sieving.

The necessary difference among ultrafiltration and microfiltration is the size of the macrosolute retained, pore size of the membranes and the hydrostatic pressure needed across the membranes. A classic application of microfiltration process is in the removal of bacteria from water samples and removal of submicron size suspended dust and particulate matters from gas streams. Removal of chemical oxygen demand from effluent waters is the other important application of the MF procedure.