Process intensification of municipal wastewater treatment by aerobic granular sludge systems

摘要

Stable aerobic granulation at low oxygen concentrations can take place using a discontinuously system, with anaerobic feeding followed by an aerobic reaction period. High COD-, N- and P-removal efficiencies are obtained in a laboratory scale reactor, fed with synthetic wastewater. In a short experiment, formation of aerobic granules on pre-settled sewage is shown too. A technical and economical feasibility study for the treatment of municipal sewage has been carried out. Depending on the chosen process configuration, a high effluent quality is viable. Based on total annual costs, the aerobic granular sludge system was more attractive (7-17%) than the reference alternative, a conventional activated sludge plant. Because of the high permissible load, the footprint of the aerobic granular sludge variant is only 25% compared to the reference. The aerobic granule based system can be attractive, especially when the expected more stringent effluent demands have to be fulfilled.