Treatment of municipal wastewater by employing membrane bioreactors combined with efficient nitration microbial communities isolated by Isolation Chip with Plate Streaking technology.

In this research, we developed a method so-called Isolation Chip with Plate Streaking (ICPS) to selectively enrich nitrifying microbial consortium for treating municipal wastewater. In batch experiment, these bacterial communities were able to remove NH3 -N in 72 h with an efficiency of 96%. Firmicutes, Bacteroidetes, and Proteobacteria species are dominant bacteria in these communities. When the bacterial communities were used in the membrane bioreactor under typical condition, the removal efficiency was 81.0%. In contrast, under the actual wastewater condition, the efficiency could reach 91.2%. All above results showed clearly that the consortium selected by our ICPS method could achieve high-efficient NH3 -N removal, thus offering a reliable technique for screening functional microorganisms in the field of water treatment. PRACTITIONER POINTS: ICPS technology was designed and used for screening specialized NH3 -N-removing isolates. The screening process benefited the growth of the dominant nitrifying bacteria Firmicutes and Bacteroidetes. When the functional bacteria applied into the MBR, the NH3 -N removal efficiency was 91.2% under actual wastewater conditions.