The efficiency of biological processes depends on two main factors: the biomass concentration in the reactor and the ratio of specific micro-organism transformation. Most attempts to improve the biological processes in the last hundred years have had the objective of increasing the micro-organism concentration in the reactor, or separating the solids and liquids and then recirculating the biomass (activated sludge), or developing fixed reactors for the cultivation of the micro-organisms which are on a support.

The latest developments for a new generation of UF and MF more productive membranes but less expensive has made a new concept of biological treatment arise: the membrane bioreactor (MBR).

So, a membrane bioreactor can be defined as the combination of two processes, biological degradation and a separation by membrane, in one.

The membrane can be joined to the biological section externally or internally, sinking them in the reactor itself.

 

MBR flow scheme