DESIGN AND OPERATION OF ANAEROBIC MEMBRANE BIOREACTORS - DEVELOPMENT OF A FILTRATION TESTING STRATEGY

Historically, high performance anaerobic wastewater treatment processe s have been developed by maximizing the retention of microorganisms ei ther by fixing them on porous material or by favoring the growth of ea sy-settling microbial granules. While numerous studies have been direc ted towards the comprehension of the various processes involved in the fixation of microorganisms or the formation of microbial granules, mu ch less work has been devoted to the improvement of solid-liquid separ ation techniques. The recent development of a new generation of ultra- filtration membranes more productive and less expensive has however pr ompted the emergence of a new concept in the wastewater treatment tech nology: the membrane bioreactor. The study is aimed at the determinati on of the optimal operating condition of an anaerobic membrane bioreac tor. The influence of biological and physico-chemical parameters on th e overall performance was evaluated. It was found that the performance of the biological component of the system depended mainly on the mass loading while that of the separative part was influenced only by phys ical parameters such as pressure, cross-flow velocity and suspended so lids concentration. A filtration testing procedure was developed and s everal relationships were established between the various operating pa rameters of a membrane bioreactor.