Development of a novel hybrid UAFB-anoxic-aerobic MBR for energy production and nutrients removal from domestic wastewater

The combined treatment process making up of up-flow anaerobic sludge fixed bed (UAFB), anoxic tank and aerobic membrane bioreactor (MBR) was used to treat domestic wastewater. And the ability of reclaiming methane and reusing wastewater was investigated. The efficiency of the combined treatment process treating wastewater at optimized parameters was studied in this paper. The combined treatment process treating domestic wastewater run at optimized parameters (20°C, HRT were 3 h, 3 h, 3.5 h) indicated that, the anaerobic gas production was 1.55 L/d, the COD and NH₄⁺-N removal efficiency were 93.28% and 90.60% respectively, UAFB effluent including 54.74 mg/L of total VFAs, corresponding NO₃^--N accumulating rate was 45.19% and TN removal efficiency was 45.51%. At the same time, it was found that sludge concentration of anoxic tank and aerobic MBR could be maintained at a low level, which is so rich in significance for sludge reduction and delaying membrane fouling.