The basic Microfiltration Outside-in Filtration (MOF) or Ultrafiltration Outside-in Filtration (UOF) devices are shown below. It comprises a large number of hollow fibres contained within a PVC module. The module caps at each end allow water to enter at the base and flow upwards through the module. Solids free water (permeate) passes through the membrane pores, into the membrane lumen and out of the system. Polluted water flows along the side of the membranes and is recirculated (as concentrate) to the raw water tank. As polluted water passes over the membrane surface, some pollutants are trapped in the pores and on the membrane surface. At intervals the fibres are backwashed with a combination of air, water and chemical to clean the pores and restore the permeate flow.
|
|||||||||||||||
