Performance of micro-pressure double-cycle coupled membrane integrated bioreactor for the treatment of urban sewage

Based on the theory of nitrogen and phosphorus removal and technical requirements, a micro-pressure double-cycle bioreactor coupled with membrane components was used to treat municipal wastewater. The method realized the simultaneous removal of organic matter, nitrogen, and phosphorus in the same reactor and had the characteristics of membrane bioreactor process. Results showed that the average removal efficiency of COD, NH + 4 -N, TN, and TP were 93.74%, 95.1%, 71.85%, and 81.03%, respectively. During operation, Proteobacteria and Bacteroidetes were the main dominant bacteria, and they had complete nitrogen and phosphorus metabolic pathways. Owing to the low protein content in the mixture, the design of film placement in the micro-precipitation zone was conducive to alleviating the membrane pollution caused by the accumulation of protein, thereby improving the effluent quality and extending the service life of the membrane components. Graphical abstract