The membrane biological reactor (MBR) system consists of a suspended-growth biological reactor combined with a membrane ultrafiltration unit process. It is particularly attractive in situations where long solids retention times are required, and physical retention and subsequent hydrolysis are critical to achieving biological degradation of pollutants. In order to develop full scale process design information, a large pilot system was operated for eleven months. The pilot project involved assessing performance and developing design information for the system in the treatment of wastewater from two General Motors (GM) facilities. The pilot system results provided a basis for design of a full scale, demonstration MBR system for treatment of industrial wastewater. Case history information is presented in this paper on the design of the MBR system and subsequent operation and performance. Despite certain design issues, the system has met or exceeded performance expectations.
