Nitrite accumulation by aeration controlled in sequencing batch reactors treating domestic wastewater

Abstract

The feasibility of obtaining and keeping stable nitrite accumulation in Sequencing Batch Reactors (SBRs) treating domestic wastewater is studied. The final product of ammonium oxidation is either reproducible nitrate or nitrite depending on the aeration strategy. With the aerobic-anoxic sequence, two SBRs fed with domestic wastewater are operated in parallel. One SBR (SBR1) is controlled by the aeration control strategy, and the other SBR (SBR2) by alternate aeration control strategy. Based on the on-line indirect measurements of DO and pH, the relationship between pH (or DO) and nitrogen concentration (NH4+-N, NO3−-N and NO2−-N) is investigated. The result indicates that pH and DO can be used as control parameters for the real-time aeration control strategy to obtain nitritation in SBR treating domestic wastewater. The result of SBR1 indicates that long-term stable nitritation is possible at 32 ± 1°C. The result of SBR2 indicates that the aeration control strategy is necessary for nitritation during the acclimation period, because the nitrite accumulation disappears when the aeration is extended.

Biological nitrogen removal with nitrification and denitrification via nitrite pathway

“…Therefore, low DO concentration is more restrictive for the growth of NOB than AOB, which will result in nitrite accumulation (Peng et al 2004a).…”

“…According to Baumann et al (1997), an anoxic period of 4 h is sufficient to synthesize all enzymes and have complete denitrification. Besides, Peng et al (2004a) reported that using aeration control strategy partial nitrification had been achieved, although the temperature was decreased from 32 to 21°C.…”

Achieving the nitrite pathway using aeration phase length control and step‐feed in an SBR removing nutrients from abattoir wastewater

“…The accumulation of nitrite has also been shown to trigger the emission of nitrous oxide (N 2 O) during the denitrification step (Itokawa et al, 2001;Zeng et al, 2003a). Peng et al (2004) demonstrated that stable N removal via nitrite could be obtained through the control of the aeration time in a sequencing batch reactor (SBR) treating domestic wastewater. Aeration was stopped as soon as nitritation finished (i.e., complete oxidation of NH þ 4 ), as indicated by a bending point on the pH profile.…”

Population balance models: a useful complementary modelling framework for future WWTP modelling

“…These potential benefits however come with challenges associated with NOB outselection under cold and diluted loading conditions. While the operational strategies are well documented for sidestream applications (Gut et al, 2005;Hellinga et al, 1998;van de Graaf et al, 1996;van Loosdrecht and Salem, 2005;Wett et al, 2007), many recent studies were conducted to address these challenges for mainstream applications using nitritation/denitritation (Blackburne et al, 2008;Gao et al, 2009Gao et al, , 2014Peng et al, 2004Peng et al, , 2012Regmi et al, 2013) and deammonification Hu et al, 2013;Lotti et al, 2013;Wett et al, 2013;Winkler et al, 2011) or both (Vlaeminck et al, 2012;. Several mechanisms were identified by which the three autotrophic groups, i.e.…”