Operation of three parallel AN/AO processes to enrich denitrifying phosphorus removing bacteria for low strength wastewater treatment

Article type: Research Article

Authors: XIA, Si-qing | LIU, Hong-bo

Affiliations: State Key Lab of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China

Note: [] Corresponding author. E-mail: [email protected]

Abstract: Three parallel anaerobic-anoxic/anaerobic-aerobic (AN/AO) processes were developed to enrich denitrifying phosphorus removal bacteria (DPB) for low strength wastewater treatment. The main body of the parallel AN/AO process consists of an AN(anaerobic-anoxic) process and an AO (anaerobic-aerobic) process. In the AO process, the common phosphorus accumulating organisms (PAOs) was dominate, while in the AN process, DPB was dominate. The volume of anaerobic zone (V_{ana}):anoxic zone (V_{ano}): aerobic zone (V_{aer}) for the parallel AN/AO process is 1:1:1 in contrast with a V_{ana}:V_{aer} and V_{ano}:V_{aer} of 1:2 and 1:4 for a traditional biological nutrient removal process (BNR). Process 3 excels in the 3 processes on the basis of COD, TN and TP removal. For 4 month operation, the effluent COD concentration of process 3 did not exceed 60 mg/L; the effluent TN concentration of process 3 was lower than 15 mg/L; and the effluent TP concentration of process 3 was lower than 1 mg/L.

Keywords: parallel AN/AO process, denitrifying phosphorus removing bacteria (DPB), low strength wastewater, biological nutrient removal (BNR)

Journal: Journal of Environmental Sciences, vol. 18, no. 3, pp. 433-438, 2006