Estimation of countrywide N2O emissions from wastewater treatment in Switzerland using long-term monitoring data

Successful year-round mainstream partial nitritation anammox: Assessment of effluent quality, performance and N2O emissions

“…With an average DO of 3–4 mgO 2 /L during regular reactor operation, an average of 1.2±1 % of total nitrogen in the influent ( Table 1 , 47 ± 12 mgTN/L) were emitted as N 2 O. This is close to the average N 2 O emission factor of 0.9% for N/D WWTP in Switzerland ( Gruber et al., 2021 ). As demonstrated here, N 2 O stable isotope analyses may provide a useful analytical tool to gain a deeper understanding of biological and, possibly, abiotic N 2 O production and consumption pathways.…”

Nitrous Oxide Emissions and Carbon Footprint of Decentralized Urine Fertilizer Production by Nitrification and Distillation

“…10 The emission factor for the whole urine fertilizer production was estimated at 1.5%. For comparison, Gruber (2021) 15 calculated an emission factor of 2% for a model WWTP where 60% of emissions came from the mainstream nitrification and denitrification and secondary clarifier, and 40% from the sidestream treatment and sludge incineration.…”

“…N 2 O from wastewater treatment is mainly produced by ammonia-oxidizing bacteria (AOB) through hydroxylamine oxidation and nitrifier denitrification, and by heterotrophic denitrifying bacteria . N 2 O emissions measured at WWTP are highly dynamic and depend strongly on factors such as influent characteristics, nitrogen removal efficiency, and stability of nitrification . N 2 O emissions are usually reported as emission factors (EF N 2 O ) relative to the total nitrogen (TN) load in the influent expressed as [g N 2 O-N g-N –1 ] or [%].…”

“…14 N 2 O emissions measured at WWTP are highly dynamic and depend strongly on factors such as influent characteristics, nitrogen removal efficiency, and stability of nitrification. 15 N 2 O emissions are usually reported as emission factors (EF Nd 2 O ) relative to the total nitrogen (TN) load in the influent expressed as [g N 2 O-N g-N −1 ] or [%]. For mainstream nitrification in WWTPs, EF Nd 2 O generally ranges from 0.01 to 2% of the TN load for the majority of the different process groups.…”

“…For mainstream nitrification in WWTPs, EF N 2 O generally ranges from 0.01 to 2% of the TN load for the majority of the different process groups . For full-scale continuous long-term studies, an average EF of 0.9% has recently been suggested for WWTP with nitrification and denitrification, which is lower than the EF N2O of 1.6% recommended by the updated IPCC guidelines as an assumption for WWTP . The EF N 2 O from sidestream processes is generally considered to be higher ranging from 0.2 to 5.1%, which is among others related to higher ammonia oxidation rate and nitrite accumulation …”