The influence of aeration control and temperature reduction on nitrogen removal and microbial community in two anammox‐based hybrid sequencing batch biofilm reactors

BACKGROUND Two hybrid biofilm reactors, an integrated fixed-film activated sludge–sequencing batch reactor (IFAS-SBR) and a SBR with mixture of sludge granules, were used to reach enhanced nitrogen removal based on the anaerobic ammonium oxidation (anammox) process under intermittent aeration. RESULTS IFAS-SBR reached more stable performance after rapid start-up period 25 days, it showed reliable than other reactor. The highest efficiency (NRE) was up 99% NH4+-N concentration 91% total (TIN). A rate 0.01 0.15 kgN m−3 d−1 achieved throughout operation TIN. set-point maximum dissolved oxygen (DO) at peak each aeration cycle maintained 1.2 ± 0.1 mg L−1. optimum working range for daily average DO 0.2–0.7 Cold temperatures caused decline NRE, but NRE > 50% above 13 °C achieved. CONCLUSIONS Results implied higher abundance Candidatus brocadia species anammox bacteria in samples Denitratisoma genus flocs. most substantial contribution shared taxa among all class level Betaproteobacteria Gammaproteobacteria, least abundant Nitrospira. Overall, results that is robust configuration anammox-based sidestream, controlled could suppress nitrite help regain system efficiency.