scholarly journals Denitrication and N₂O production in Canadian Lakes: effects of nutrient ratios acting through primary producer selection

2021 ◽  
Author(s):  
Joseph James Bautista
Keyword(s):  
Nitrous Oxide ◽  
Organic Matter ◽  
Nutrient Loading ◽  
Nutrient Ratios ◽  
Green Algal ◽  
Laboratory Bench ◽  
Nitrous Oxide Production ◽  
Mesocosm Experiments ◽  
Primary Producer ◽  
Loading Ratio

Anthropogenic nutrient loading to aquatic systems may increase atmospheric release of nitrous oxide (N₂O) greenhouse gas by enhancing denitrification and/or nitrification. High Si:N loading may favour diatom abundance, whereas low N:P loading may favour cyanobacteria dominance. Systems with diatom or green algal dominance may have greater export of organic matter to sediments, whereas systems dominated by cyanobacteria may have organic matter recycled within the water column due to differences in cell density and sinking. With increased export of organic matter to sediments, denitrification and N₂O production may be stimulated. In laboratory bench-scale microcosms, nitrous oxide production was affected by Si:N loading ratios as predicted, although N:P loading did not affect N₂O production in the manner predicted. However, the predicted effects of nutrient loading ratio on microphyte community composition were not supported by microscopy. Field mesocosm experiments indicated no significant relationship between N₂O production and nutrient loading ratios.

scholarly journals Denitrication and N₂O production in Canadian Lakes: effects of nutrient ratios acting through primary producer selection

2021 ◽  
Author(s):  
Joseph James Bautista
Keyword(s):  
Nitrous Oxide ◽  
Organic Matter ◽  
Nutrient Loading ◽  
Nutrient Ratios ◽  
Green Algal ◽  
Laboratory Bench ◽  
Nitrous Oxide Production ◽  
Mesocosm Experiments ◽  
Primary Producer ◽  
Loading Ratio

Anthropogenic nutrient loading to aquatic systems may increase atmospheric release of nitrous oxide (N₂O) greenhouse gas by enhancing denitrification and/or nitrification. High Si:N loading may favour diatom abundance, whereas low N:P loading may favour cyanobacteria dominance. Systems with diatom or green algal dominance may have greater export of organic matter to sediments, whereas systems dominated by cyanobacteria may have organic matter recycled within the water column due to differences in cell density and sinking. With increased export of organic matter to sediments, denitrification and N₂O production may be stimulated. In laboratory bench-scale microcosms, nitrous oxide production was affected by Si:N loading ratios as predicted, although N:P loading did not affect N₂O production in the manner predicted. However, the predicted effects of nutrient loading ratio on microphyte community composition were not supported by microscopy. Field mesocosm experiments indicated no significant relationship between N₂O production and nutrient loading ratios.

Nitrous oxide production by nitrifying biofilms in a biofilm airlift suspension reactor

1997 ◽  
Vol 36 (1) ◽  
pp. 157-163 ◽  
Author(s):  
J. M. Garrido ◽  
J. L. Campos ◽  
R. Méndez ◽  
J. M. Lema
Keyword(s):  
Nitrous Oxide ◽  
Organic Matter ◽  
Carbon Source ◽  
Nitrogen Balance ◽  
Loading Rate ◽  
Experimental Period ◽  
Major Product ◽  
Oxide Production ◽  
Nitrous Oxide Production

A nitrifying biofilm airlift suspension (BAS) reactor was operated at an ammonia loading rate (ALR) of 5 kg N-NH4+/m3•d, obtaining ammonia conversions of 99%. Neither denitrification nor nitrous oxide production was detected when a suitable carbon source was not present in the system over a long experimental period. However, in the presence of organic matter coming from biofilm hydrolysis or added in the influent nitrous oxide production was found. The addition of 55 mg/l formaldehyde to the influent produced rises in the nitrous oxide production of up to 2 kg N-N2O/m3•d. Nitrogen balance showed that nitrous oxide was the sole or major product of denitrification in the system.

Nitrous oxide production in two forested watersheds exhibiting symptoms of nitrogen saturation

1998 ◽  
Vol 28 (11) ◽  
pp. 1723-1732 ◽  
Author(s):  
William T Peterjohn ◽  
Richard J McGervey ◽  
Alan J Sexstone ◽  
Martin J Christ ◽  
Cassie J Foster ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
Nitrogen Saturation ◽  
N Cycling ◽  
Woody Vegetation ◽  
N Saturation ◽  
Relative Importance ◽  
Forested Watersheds ◽  
Total N ◽  
Nitrous Oxide Production ◽  
Poorly Drained Soils

A major concern about N saturation is that it may increase the production of a strong greenhouse gas, nitrous oxide (N2O). We measured N2O production in two forested watersheds, a young, fertilized forest (WS 3) and an older, unfertilized forest (WS 4), to (i) assess the importance of N2O production in forests showing symptoms of N saturation; (ii) estimate the contribution of chemoautrophic nitrification to total N2O production; and (iii) examine the relative importance of factors that may control N2O production. During the study period, mean monthly rates of N2O production (3.41-11.42 µ N ·m-2·h-1) were consistent with measurements from other well-drained forest soils but were much lower than measurements from N-rich sites with poorly drained soils. Chemoautotrophic nitrification was important in both watersheds, accounting for 60% (WS 3) and 40% (WS 4) of total N2O production. In WS 3, N2O production was enhanced by additions of CaCO3 and may be constrained by low soil pH. In WS 4, N2O production on south-facing slopes was exceptionally low, constrained by low NO3 availability, and associated with a distinct assemblage of woody vegetation. From this observation, we hypothesize that differences in vegetation can influence N cycling rates and susceptibility to N saturation.

scholarly journals Low nitrous oxide production through nitrifier-denitrification in intermittent-feed high-rate nitritation reactors

2017 ◽  
Vol 123 ◽  
pp. 429-438 ◽  
Author(s):  
Qingxian Su ◽  
Chun Ma ◽  
Carlos Domingo-Félez ◽  
Anne Sofie Kiil ◽  
Bo Thamdrup ◽  
...  
Keyword(s):  
Nitrous Oxide ◽  
High Rate ◽  
Oxide Production ◽  
Nitrifier Denitrification ◽  
Nitrous Oxide Production
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