Integration of membrane filtration into the activated sludge process in municipal wastewater treatment

Abstract

Energy-efficient membrane modules for microfiltration are available to realize a new process engineering in municipal wastewater treatment. The microfiltration membrane ensures that all microorganisms are retained in the aeration tank. A content of mixed-liquor suspended solids of e.g. 15 gMLSS/l can easily be achieved in a large scale plant. Thus the aeration tank is considerably reduced in size. A secondary clarifier is no longer needed. A filtration and a disinfection can be dismissed. A pilot plant gives first knowledge on the application of the activated sludge process with submersed membrane filtration. Based on the tests' results and the knowledge gained during the operation of the pilot plant, a WWTP with membrane filtration for 3000 inhabitants is designed. The costs of investment and operation are estimated.