Enhancing Nitrogen Removal Efficiency through Partial Nitrification-Denitrification in the integrated internal circulation aerated reactor: Microbial Evolution.

An integrated internal circulation aerated bioreactor, possessing a high circulation ratio and the capability to generate oxygen gradients, was optimized and developed in this study, using an air-lift circulating reactor as a foundation, for the treatment of urban sewage. Under the optimal conditions (sludge concentration of 5000 mg/L, HRT of 8 h , and aeration rate of 0.6 L/min), The ammonia oxidation rate and nitrite reduction rate have increased by 35.0% and 213.3%, respectively, significantly improving the nitrogen removal efficiency. The biological samples were 16S sequencing data of sludge samples before and after reactor domestication, which revealed the changing pattern of microbial community inside the reactor.