- Alterra - Sustainable soil management (1)
- Environmental Technology (1)
- Sub-department of Environmental Technology (1)
- Sustainable Soil Management (1)
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N2O consumption by low-nitrogen soil and its regulation by water and oxygen
Wu, D.M. ; Dong, W.X. ; Oenema, O. ; Wang, Y.Y. ; Trebs, I. ; Hu, C.S. - \ 2013
Soil Biology and Biochemistry 60 (2013). - ISSN 0038-0717 - p. 165 - 172.
spruce forest soil - aerobic denitrification - oxide - fluxes - emissions - exchange - n-2 - no - bacteria - nitrate
Soils can be a source and sink for atmospheric nitrous oxide (N2O). Consumption of N2O has been reported for anoxic soils and sediments rich in organic matter and depleted in nitrates (NO3-), and also for some dry, oxic soils. However, the mechanisms and controls of N2O consumption in dry soil are not clear. Here, we report on a field study in China (Taihang mountain region, Shijiazhuang), in which N2O uptake by a sandy loam soil was measured for the greater part of the season (from April to October in 2011), and on four incubation experiments, in which we tried to reveal the roles of water content and oxygen (O-2) concentrations on N2O consumption. Flux measurements in the field were made bi-weekly on unfertilized cropped land with static flux chambers (5 replicates) for 6 months. The results show that N2O-N fluxes ranged from -26.0 to -726.6 mu g m(-2) h(-1). Consumption of N2O was largest when the soil was dry (5-20% soil water filled pore space). In the incubation experiments, N2O consumption and N-2 production were measured in (an)aerobic soil with soil moisture content ranging from 1% to 50% (wt/wt) and with N2O addition, using a thermostatic, robotized incubation system. Under anaerobic conditions, N2O was rapidly consumed at water content of >10% (wt/wt). However, a significant consumption also occurred at 1% soil moisture. Under aerobic conditions, N2O consumption increased with increasing soil moisture content, but significant consumption was still measured at 2% moisture. Sterilization of oxic soil completely blocked N2O consumption, suggesting that the consumption had a biological nature. In conclusion, the steady N2O consumption measured in the field was confirmed by the laboratory experiments, but the relationship with soil moisture content was reversed. Further studies are required to understand this apparent anomaly.
Nitrous oxide emission during wastewater treatment
Kampschreur, M.J. ; Temmink, B.G. ; Kleerebezem, R. ; Jetten, M.S.M. ; Loosdrecht, M.C.M. - \ 2009
Water Research 43 (2009)17. - ISSN 0043-1354 - p. 4093 - 4103.
denitrificatie - broeikaseffect - stikstofoxide - nitrificatie - distikstofmonoxide - afvalwaterbehandeling - broeikasgassen - stikstof - verwijdering - denitrification - greenhouse effect - nitric oxide - nitrification - nitrous oxide - waste water treatment - greenhouse gases - nitrogen - removal - biological phosphorus removal - denitrifying activated-sludge - sequencing batch reactor - treatment-plant - alcaligenes-faecalis - dinitrogen oxide - n2o production - simultaneous nitrification - aerobic denitrification - autotrophic nitrifiers
Nitrous oxide (N2O), a potent greenhouse gas, can be emitted during wastewater treatment, significantly contributing to the greenhouse gas footprint. Measurements at lab-scale and full-scale wastewater treatment plants (WWTPs) have demonstrated that N2O can be emitted in substantial amounts during nitrogen removal in WWTPs, however, a large variation in reported emission values exists. Analysis of literature data enabled the identification of the most important operational parameters leading to N2O emission in WWTPs: (i) low dissolved oxygen concentration in the nitrification and denitrification stages, (ii) increased nitrite concentrations in both nitrification and denitrification stages, and (iii) low COD/N ratio in the denitrification stage. From the literature it remains unclear whether nitrifying or denitrifying microorganisms are the main source of N2O emissions. Operational strategies to prevent N2O emission from WWTPs are discussed and areas in which further research is urgently required are identified