Denitrifying phosphorus removal in a step-feed CAST with alternating anoxic-oxic operational strategy

作者：Ma Juan; Peng Yongzhen^*; Wang Shuying; Wang Li; Liu Yang; Ma Ningping

来源：Journal of Environmental Sciences, 2009, 21(9): 1169-1174.

DOI：10.1016/S1001-0742(08)62398-0

• cyclic activated sludge technology
• biological phosphorus removal
• denitrifying polyphosphate-accumulating organisms

A bench-scale cyclic activated sludge technology (CAST) was operated to study the biological phosphorus removal performance and a series of batch tests was carried out to demonstrate the accumulation of denitrifying polyphosphate-accumulating organisms (DNPAOs) in CAST system. Under all operating conditions, step-feed CAST with enough carbon sources in influent had the highest nitrogen and phosphorus removal efficiency as well as good sludge settling performance. The average removal rate of COD, NH(4)(+)-N, PO(4)(3-)-P and total nitrogen (TN) was 88.2%, 98.7%, 97.5% and 92.1%, respectively. The average sludge volume index (SVI) was 133 mL/g. The optimum anaerobic/aerobic/anoxic (AOA) conditions for the cultivation of DNPAOs could be achieved by alternating anoxic/oxic operational strategy, thus a significant denitrifying phosphorus removal occurred in step-feed CAST. The denitrification of NOx(-)-N completed quickly due to step-feed operation and enough carbon sources, which could enhance phosphorus release and further phosphorus uptake capability of the system. Batch tests also proved that polyphosphate-accumulating organisms (PAOs) in the step-feed process had strong denitrifying phosphorus removal capacity. Both nitrate and nitrite could be used as electron acceptors in denitrifying phosphorus removal. Low COD supply with step-feed operation strategy would favor DNPAOs accumulation.

• 出版日期2009
• 单位北京工业大学