Intermittent rotation as an innovative strategy for achieving nitritation in rotating biological contactors

Ammonium load determines the performance of a continuous nitritation process and the related microbial communities even under excesses of O2 supply

“…These apparently contradictory outcomes strongly suggested that other parameters apart from the DO concentration should be considered in nitritation processes. It is important to note that those studies where a DO concentration <1 g m −3 was effective for establishing a high nitritation performance were operated under ammonium loading rates in the range of ~14 to ~140 gN‐NH 4 + m −3 h −1 , 8,30,32 whereas ammonium loadings of 1 to ~6 gN‐NH 4 + m −3 h −1 were set in the works where a low DO concentration was not efficient for establishing high selectivity to nitrite 35,36 . In the present study, ammonium loading rates of 2.5 and 5.1 gN‐NH 4 + m −3 h −1 were tested in experimental phases I–VI, the nitritation performance agreeing with those studies where DO control was insufficient to have a high nitrite selectivity.…”

“…anoxic H 2 S removal), and anoxic treatment of volatile organic compounds. 1,8,9 Nitritation processes are based on the predominance of AOB over NOB, yielding nitrite as the main ammonium oxidation product. Operational parameters such as temperature, pH, carbon/ nitrogen (C:N) ratio, and dissolved O 2 concentration (DO) are the most reported factors to be controlled for establishing nitritation processes.…”

“…10,11 On the one hand, controlling the DO concentration has been consistently considered as the critical parameter for achieving a high-performance nitritation. 5,6,8,12,13 On the other, most nitritation studies available in the literature have been performed in sequencing batch reactors (SBR). 10,11,14 SBR configuration offers the flexibility to sequentially set aerobic (i.e.…”

“…anammox), biogas purification (i.e. anoxic H 2 S removal), and anoxic treatment of volatile organic compounds 1,8,9 …”

“…Operational parameters such as temperature, pH, carbon/nitrogen (C:N) ratio, and dissolved O 2 concentration (DO) are the most reported factors to be controlled for establishing nitritation processes 10,11 . On the one hand, controlling the DO concentration has been consistently considered as the critical parameter for achieving a high‐performance nitritation 5,6,8,12,13 . On the other, most nitritation studies available in the literature have been performed in sequencing batch reactors (SBR) 10,11,14 .…”