Microbial Diversity of a Municipal Wastewater Treatment System Based on a Partitioned and Multistage Pure Mbbr Process

A pure moving bed biofilm reactor (pure MBBR) system with a two-stage anoxic/oxic (A/O) process was applied in a full-scale WWTP in northern China. The front A/O subsystem consisted of three anoxic (A1, A2, A3) and four oxic reactors (O1, O2, O3, O4), and the post A/O subsystem consisted of one anoxic (post-A) and oxic reactor (post-O). High-throughput sequencing was adopted in combination with the operation effect of the system, and the relationship between the pollutant removal effect and microbial diversity was assessed. The results showed that A1, A2 and post-A were the core denitrification functional areas. O2, O3 were mainly rich in Nitrispira , which plays a major role in nitrification. The treatment load of each reactor mainly depends on the effective content of functional bacteria. In addition, the pure MBBR system can improve the enrichment efficiency of Candida brocadia , and provide the possibility to realize mainstream ANAMMOX.