Nitrite effect on nitrous oxide emission from denitrifying activated sludge

Nitritation and N2O Emission in a Denitrification and Nitrification Two-Sludge System Treating High Ammonium Containing Wastewater

“…Alinsafi et al [36] obtained that during denitrification with NO3-N as the electron acceptor, a low C/N ratio caused NO2-N accumulation, inhibited N2O reductase and induced N2O emissions. Itokawa et al [37] found that at the low C/N ratio, NO2-N existence and endogenous denitrification were the main reasons for the increased N2O emissions.…”

“…Some studies showed that the inhibitory effect of denitrifiers was not directly due to NO2-N, but due to its role in the biological formation of NO, which was a highly toxic compound [38]. Hence, during denitrification with NO2-N as the electron acceptor, it was possible that a low C/N ratio meant a carbon shortage and led to NO accumulation, which inhibited the activity of denitrification and induced increased N2O emissions; in addition, NO2-N might inhibit the N2O reductase activity and cause N2O emissions [36,39]. The N2O emission factor during denitrification under different C/N ratios was in the range of 12.0%-26.6%.…”

“…The N2O emission factor during denitrification under different C/N ratios was in the range of 12.0%-26.6%. Alinsafi et al [36] obtained N2O emission factors during denitrification with NO3-N as the electron acceptor of 5.1%, 2.6% and 1% at C/N ratios of 3, 5 and 7, respectively. The N2O emission factor in this study was relatively high, which could be due to NO2-N being the electron acceptor.…”

Batch treatment of liquid fraction of pig slurry by intermittent aeration: process simulation and microbial community analysis

“…Nevertheless, factors described here such as wastewaters with a low BCOD/N ratio, presence of nitrite and low DO concentrations may favour emissions of these greenhouse gases. 46 Further model improvements should consider the emission of nitrogen oxides in relation to the applied operational conditions. Finally, the typology of biodegradable organic substrates and their influence on nitrite accumulation during denitrification must be better characterized and included in the model statement.…”

Water and Air Quality Performance of a Reciprocating Biofilter Treating Dairy Wastewater

“…Nitrite is an intermediate compound in the nitrification of ammonia to nitrate and can be found at high concentrations in reactors that favor incomplete nitrification-denitrification, which is usually caused by chronically low dissolved oxygen concentrations. Nitrite accumulation in a nitrification-denitrification bioreactor has been found to increase nitrous oxide emissions, especially when coupled with low organic carbon concentrations (Alinsafi et al 2008). It is important to identify the operational parameters that would maintain low concentrations of nitrite in any nitrification-denitrification reactor to keep N 2 O emissions to a minimum.…”