Advanced nitrogen and phosphorus removal in pilot-scale anaerobic/aerobic/anoxic system for municipal wastewater in Northern China

[Display omitted] •30 m3 anaerobic/aerobic/anoxic pilot-scale SBR system was first set up with sewage.•Total nitrogen and phosphate in effluent were 10.9 and 0.1 mg/L at 15.7℃.•The relative abundance of Competibacter and Tetrasphaera rose to 1.25% and 1.52%.•The contribution rate by endogenous denitrification was more than 43.3%.•Sludge reduction (17.1 %) and short aerobic time (6.0 h) helped to save energy. Removing nitrogen and phosphorus from low ratio of chemical oxygen demand to total nitrogen and temperature municipal wastewater stays a challenge. In this study, a pilot-scale anaerobic/aerobic/anoxic sequencing batch reactor (A/O/A-SBR) system first treated 15 m3/d actual municipal wastewater at 8.1–26.4 °C for 224 days. At the temperature of 15.7 °C, total nitrogen in influent and effluent were 45.5 and 10.9 mg/L, and phosphorus in influent and effluent were 3.9 and 0.1 mg/L. 16 s RNA sequencing results showed the relative abundance of Competibacter and Tetrasphaera raised to 1.25 % and 1.52 %. The strategy of excessive, no and normal sludge discharge enriched and balanced the functional bacteria, achieving an endogenous denitrification ratio more than 43.3 %. Sludge reduction and short aerobic time were beneficial to energy saving contrast with a Beijing municipal wastewater treatment. This study has significant implications for the practical application of the AOA-SBR process.