The term ‘membrane bioreactor’ (MBR) is generally used to define wastewater treatment processes where a perm-selective membrane, eg. microfiltration or ultrafiltration is integrated with a biological process – a suspended growth bioreactor.

MBRs differ from ‘polishing’ processes where the membrane is employed as a discrete tertiary treatment step with no return of the active biomass to the biological process. All commercial MBR processes available today use the membrane as a filter, rejecting the solid materials which are developed by the biological process, resulting in a clarified and disinfected product effluent.

A membrane bio reactor is essentially a version of the conventional activated sludge (CAS) system. While the CAS process uses a secondary clarifier or settlement tank for solid/liquid separation, an MBR uses a membrane for this function. This provides a number of advantages relating to process control and product water quality.
APG-Neuros one of the first manufacturers to provide high speed turbo blowers in MBR wastewater treatment facilities, working with MBR manufacturers such as GE, Evoqua (formally Siemens) and KOCH, currently APG-Neuros has more than 110 units in operation in MBR application.