Biological nutrient removal in a continuous anaerobic-aerobic-anoxic process treating synthetic domestic wastewater

摘要

A continuous anaerobic-aerobic-anoxic (AOA) process was established to remove nutrients from domestic wastewater without the addition of external carbon source. The AOA process was based on an enhanced biological phosphorous removal (EBPR) system with influent COD, NH4~-—N and PO4~(3-)— P concentrations of 300, 50 and 3.8 mg/L, respectively. Nitrogen and phosphorous were removed simultaneously driven by internal carbon sources under low dissolved oxygen (DO) condition. The removal efficiencies of total nitrogen (TN) and PO4~(3-)—P reached above 90% and 99% when the DO concentration of the aerobic unit was controlled at 1.2 ± 0.2 mg/L and the HRT of the aerobic and anoxic units were at 2 h and 4 h, respectively. Denitriflcation was mainly driven by poly-β-hydroxybutyrate (PHB), which increased via shortening the aerobic HRT. Results demonstrated that TN was removed via simultaneous nitrification and denitriflcation (SND) and denitrifying phosphorous removal in the continuous AOA process.