Pilot-scale evaluation of partial denitrification/anammox on nitrogen removal from low COD/N real sewage based on a
Qi Zhao1, Kaiqi Chen1, Jianwei Li1
1National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Engineering Research Center of Beijing, Beijing University of Technology, Beijing 100124, PR China.
Abstract:
The nitrogen removal performance of a pilot-scale biosystem was significantly improved via partial denitrification/anammox (PD/A) in real sewage with low COD/N ratio. The modified pilot plant was designed as an anaerobic/anoxic/oxic (AAO) reactor combined with a biological aerated filter. The inoculation of biocarriers into anaerobic and anoxic zones enhanced anammox and the nitrogen removal performance. Despite a COD/N ratio of 3.1, effluent total inorganic nitrogen decreased from 17.1 to 9.8 mg N/L. The anoxic unit developed as the PD/A hotspot, which was associated with the enrichment of Ca. Brocadia (2.00%) and partial denitrification functional groups (OLB14, 13.50%; Thauera, 5.45%) in the anoxic-carrier biofilms and contributed 34.1% towards total nitrogen removal. Besides improving the PD/A process, enhanced denitrifying dephosphatation was simultaneously realized, suggesting that the integration of PD/A into this modified system is a promising approach to enhance nutrient removal of low COD/N wastewater.
