The optimized microbial community composition in the integrated 2-stepsludge alkaline fermentation and A2O system might substantially improve the removal of nutrients (total nitrogen (TN) = 11%, total phosphorous (TP) = 11%), as well as the reduction of the excess sludge (42%) (Gao et al., 2011). Furthermore, significant increases were observed in the reduction of the excess sludge and the removal of nutrients in the modified OSA and sequencing batch reactor processes due to the variations in their microbial community composition (Yang et al.,2016). Nevertheless, it was difficult to adjust the operating conditions (e.g., temperature, oxidation-reduction potential, sludge retention time etc.) for enhancing the performance of the modified OSA processes due to the complex removal mechanisms (Semblante et al., 2014).