Transcriptomic insights into reduced nitrous oxide emissions in one-stage partial nitritation/anammox process exposed to sulfamethazine.

Nitrous oxide emissions treating hypersaline wastewater in suspended and attached partial nitritation - anammox reactors.

The membrane aerated biofilm reactor for nitrogen removal of wastewater treatment: Principles, performances, and nitrous oxide emissions

ABSTRACTChanges in weather and management practices such as manure and fertilizer applications have a major effect on nitrous oxide (N2O) and nitric oxide (NO) emissions from soils. N2O and NO emissions exhibit high intra- and inter-annual fluctuations, which are also highly influenced by land-use change. In this study we investigated how land-use change between grassland and cornfield affects soil N2O and NO emissions using long-term field measurements in a mollic andosol soil in Southern Hokkaido, Japan. Soil N2O and NO emissions were monitored for 5 years in a 30-year old grassland (OG), which was then plowed and converted to a cornfield for 3 years and then converted back to grassland (new grassland, NG) for another 3 years. We established four treatment plots: control, without any nitrogen (N) input (CT plot); chemical fertilizer only (F plot); chemical fertilizer and manure (MF plot); and manure only (M plot).Changing land use from OG to cornfield increased annual N2O emissions by 6–7 times, while the change from cornfield to NG resulted in a 0.3–0.6 times reduction in annual N2O emissions. N2O emissions in the newly established grassland were 2–5 times higher than those in the 30-year old grassland. Soil mineral N (NO3− and NH4+) was higher in cornfield, followed by NG and lowest in OG, while water extractable organic carbon (WEOC) did not significantly change with changing land use but tended to be higher in OG and NG than in cornfield. The ratio of WEOC to soil NO3− was the most important explanatory variable for differences in N2O emissions as land use changed. High N input, surplus soil N, and precipitation and low soil pH led to increased N2O emissions. N2O emissions in fertilizer- and/or manure-amended plots were 3–4, 2–5 and 1.4–2 times higher than those in the control treatment in OG, cornfield and NG, respectively. NO emissions were largely influenced by soil mineral N and N addition, and showed less response to changing land use. There were high inter-annual variations in both NO and N2O emissions in all plots, including the control treatment, highlighting the need for long-term measurements when determining local emission rates.

A comprehensive literature mining and analysis of nitrous oxide emissions from different innovative mainstream anammox-based biological nitrogen removal processes

N2O emission in partial nitritation-anammox process

Characterization of nitrous oxide and nitric oxide emissions from a full-scale biological aerated filter for secondary nitrification

N2O and NO emission from a biological aerated filter treating coking wastewater: Main source and microbial community

Effects of urea form and soil moisture on N2O and NO emissions from Japanese Andosols

Mechanisms of N2O production in salinity-adapted partial nitritation systems for high-ammonia wastewater treatment.

Tropical soils are important sources of nitrous oxide (N2O) and nitric oxide (NO) emissions from the Earth’s terrestrial ecosystems. Clearing of tropical rainforest for pasture has the potential to alter N2O and NO emissions from soils by altering moisture, nitrogen supply or other factors that control N oxide production. In this review we report annual rates of N2O and NO emissions from forest and pastures of different ages in the western Brazilian Amazon state of Rondonia and examine how forest clearing alters the major controls of N oxide production. Forests had annual N2O emissions of 1.7 to 4.3 kg N ha −1 y −1 and annual NO emissions of 1.4 kg N ha −1 y −1 . Young pastures of 1–3 years old had higher N2O emissions than the original forest (3.1–5.1 kg N ha −1 y −1 ) but older pastures of 6 years or more had lower emissions (0.1 to 0.4 kg N ha −1 y −1 ). Both soil moisture and indices of soil N cycling were relatively poor predictors of N2O, NO and combined N2O + NO emissions. In forest, high N2O emissions occurred at soil moistures above 30% water-filled pore space, while NO emissions occurred at all measured soil moistures (18–43%). In pastures, low N availability led to low N2O and NO emissions across the entire range of soil moistures. Based on these patterns and results of field fertilization experiments, we concluded that: (1) nitrification was the source of NO from forest soils, (2) denitrification was not a major source of N2O production from forest soils or was not limited by NO − supply, (3) denitrification was a major source of N2O production from pasture soils but only when NO − was available, and (4) nitrification was not a major source of NO production in pasture soils. Pulse wettings after prolonged dry periods increased N2O and NO emissions for only short periods and not enough to appreciably affect annual emission rates. We project that Basin-wide, the effect of clearing for pasture in the future will be a small reduction in total N2O emissions if the extensive pastures of the Amazon continue to be managed in a way similar to current practices. In the future, both N2 Oa nd NO fluxes could increase if uses of pastures change to include greater use of N fertilizers or N-fixing crops. Predicting the consequences of these changes for N oxide production will require an understanding of how the processes of nitrification and denitrification interact with soil type and regional moisture regimes to control N2 Oa nd NO production from these new anthropogenic N sources.

A meta-analysis of management practices for simultaneously mitigating N2O and NO emissions from agricultural soils

Nitrogen removal and nitrous oxide emission in the partial nitritation/anammox process at different reflux ratios

Interactive effects of aquatic nitrogen and plant biomass on nitrous oxide emission from constructed wetlands

Single-stage versus two-stage partial nitritation - anammox reactor systems for deammoniafication under hypersaline conditions

We measured nitrous oxide (N2O) and nitric oxide (NO) emissions during the snow-free season (April–November) over a 3-year period (1998–2000) from a Silandic Andosols cultivated with maize (Zea mays L.) in central Hokkaido, Japan. In May, before furrowing, composted cattle manure was broadcast onto the field at a rate of 3.0 g N m−2. After furrowing, chemical fertilizer (NH4)2SO4-N + (NH4)3PO4-N : urea-N at a ratio of 10:3 was applied to the row at a rate of 13 g N m−2. An impermeable layer lay 1.3 m below ground level. As a result, after heavy rains and during the snow-melting period, the groundwater table rose to near the ground surface. The N2O and NO emission rates ranged from 0.0 to 6.4 and from 0.00 to 0.94 mg N m−2 h−1, respectively. The highest N2O emission was observed after heavy rain in summer and autumn. The magnitude and seasonal pattern of N2O emissions from the inter row were similar to those from the row itself, although chemical fertilizer had not been applied to the inter row. In contrast, an increase in NO emissions was observed only from the row. Seasonal fluctuations in soil NH− 4 and NH− 3 concentrations and the emission ratio N2O-N/NO-N suggested that N2O and NO emitted after fertilizer application (May to early July) were produced mainly by nitrification, whereas N2O emitted after heavy rains (after mid-July) was produced mainly by denitrification. Total N2O and NO emissions during the snow-free season ranged from 0.7 to 2.8 and from 0.0 to 0.7 g N m-2, respectively, over a 3-year period. The N2O and NO emissions from our field were relatively high compared with those reported worldwide. In contrast, reported N2O emission rates from agricultural Andosols in Japan are typically lower than those from other agricultural soils in Japan and around the world. Therefore, the results of the present study suggest that high N2O emissions may occur from Japanese agricultural Andosols that are poorly drained.