Successful startup of one-stage partial nitritation and anammox system through cascade oxygen supply and potential ecological network analysis

It is challenge for the stable operation of the anaerobic ammonium oxidation (Anammox) based wastewater treatment processes. The feasibility for the startup of the partial nitritation and Anammox (PNA) process was demonstrated with cascade oxygen supply by controlling anoxic/aerobic durations. Under steady state conditions, total nitrogen removal percentages of 63.2% (pulse feeding) and 88.0% (constant feeding) were obtained with the anoxic/aerobic duration of 5 min/7min at 26 degrees C, and PNA was successfully achieved. The microbial community analysis revealed that Candidatus Kuenenia and Nitrosomonas were dominant genera of Anammox bacteria and ammonia oxidizing bacteria, respectively. Microbial interactions were examined through acylhomoserine lactones-based quorum sensing (AHLs-QS) and metagenomics analyses. N-octanoyl-homoserine lactone, N-decanoyl homoserine lactone and N-dodecanoyl homoserine lactone had obvious relationships with the abundance of the Anammox bacteria. The AHLs-QS system could control microbial interactions among Anammox bacteria, nitrifiers and heterotrophs, especially for their balances in the PNA system. (C) 2019 Elsevier B.V. All rights reserved.