Membrane Activated Process

A membrane filter usually consists of a polymer membrane that is attached to a carrier support. The pore size of an ultrafiltration membrane is in the range of 2 – 100 nm. While water molecules can pass through the membrane, activated sludge flocs and also smallest solid particles are retained.

The membrane surface is cleaned by the introduction of air. The air bubbles flow over the membrane surface and remove the adhering solids. Furthermore, the membrane is also backwashed or subjected to chemical cleaning as required.

The MBR (membrane bioreactor) or membrane activated sludge process has several advantages over conventional wastewater treatment according to the activated sludge process, because the secondary sedimentation tank is replaced by membrane filtration. Since membrane filtration is much more space-saving than a secondary clarifier, the space requirement is significantly reduced. In addition, the biomass concentration in the aeration tank can be increased, and membrane filtration ensures that the clarification process effluent is free of solids.

MBR is the abbreviation for membrane bioreactor. A membrane bioreactor is used for biological wastewater treatment and works according to the membrane activated sludge process.