A combined UASB-MBR with shortcut nitrification-denitrification for energy reduction in wastewater reclamation

摘要

Shortcut nitrification has been successfully applied in a laboratory scale nitrification-denitrificationnprocess consisting of an up-flow anaerobic sludge blanket (UASB) and an aerobic membranenbioreactor (MBR) in treating synthetic and municipal wastewater to simultaneously remove organicncarbon and nitrogen. For the treatment of synthetic wastewater, the combined system exhibited anhigh TOC removal of 98% with a steady ammonia removal efficiency of about 98% in the MBR andna total nitrogen (TN) removal efficiency of 90%. In treating municipal wastewater, due to its lownCOD concentration, removal efficiencies of TOC, ammonia and TN were 70%, 98% and 60%,nrespectively. The biogas production was around 76.4 L/m3 wastewater when treating syntheticnwastewater. However, little biogas was produced when treating municipal wastewater which wasnthe result of low organic carbon loading to the UASB. Energy analysis has demonstrated that thisnnovel shortcut nitrification process could consume less energy than a conventional process andnhave the potential of bio-energy generation via biogas production thus helping to achieve a morenfavorable energy balance.