Furthermore, successful application of bioaugmentation technology for wastewater treatment depends on the adaptation of microbial strains with the indigenous microorganisms, which means the introduced microbial strains should survive and keep activity in the received systems and do not influence the function of indigenous degrading microorganisms. As a result, daily repeated adding or embedding strategy was often adopted to avoid the influence of native microorganism and to evade the dilution effect of the withdrawals. However, it greatly enhanced the operation cost in actual applications. In this study, PCN bacteria were successfully introduced to the activated sludge system through one time addition