There are few beneficial management practices (BMPs) with demonstrated efficacy in snowmelt-dominated regions. Small reservoirs are a BMP that can help mitigate flooding and reduce sediment transport, while reducing export of dissolved nutrients. To understand controls on nitrate removal and assess how this ecosystem service can be optimized, denitrification activity was measured in reservoirs ...

The accumulation of the denitrification intermediates in wastewater treatment systems is highly undesirable, since both nitrite and nitric oxide (NO) are known to be toxic to bacteria, and nitrous oxide (N2O) is a potent greenhouse gas and an ozone depleting substance. To date, two distinct concepts for the modelling of denitrification have been proposed, which are represented by the Activated ...

The Baltic Sea is one of the most eutrophic marine areas in the world. The role of nitrogen as a eutrophicating nutrient in the Baltic Sea has remained controversial owing to a lack of understanding of nitrogen cycling in the area. We investigated the seasonal variation in sediment nitrification, denitrification, anaerobic ammonium oxidation (anammox), and dissimilatory nitrate reduction to amm...

Nitrogen (N) deposition has increased significantly globally since the industrial revolution. Previous studies on the response of gaseous emissions to N deposition have shown controversial results, pointing to the system-specific effect of N addition. Here we conducted an N addition experiment in a temperate natural forest in northeastern China to test how potential changes in N deposition alte...

Dry plant material contains 2-4% nitrogen, making it an essential nutrient for all plants. The nitrogen cycle regulates the pathways which transform nitrogen from a relatively inert dinitrogen gas to forms of organic nitrogen such as proteins and nucleic acids. Denitrification and nitrogen fixation are the two most important processes that remove and add nitrogen to the soil, respectively. The ...

We quantify relations between rates of in situ denitrification and saturated infiltration through shallow, sandy soils during managed groundwater recharge. We used thermal methods to determine time series of point-specific flow rates, and chemical and isotopic methods to assess denitrification progress. Zero order denitrification rates between 3 and 300 μmol L(-1) d(-1) were measured during inf...

Whole-system denitrification in the South Platte River was measured over a 13-month period using an open-channel N2 method and mass-balance measurements. Concentrations of dissolved N2 were measured with high precision by membrane-inlet mass spectrometry and estimates of denitrification were based on the mass flux of N2, after correction for reaeration and groundwater flux. Open-channel estimat...

Denitrification is commonly measured using in situ benthic chambers or laboratory incubations of sediment cores. These techniques are similar in principle but differ considerably in cost and practicality. Despite widespread use of both techniques, it is uncertain whether they give comparable results. We compared cores and chambers for measuring fluxes (dissolved oxygen [DO], N2, NH4, NO3 and NO...

Within fluvial systems, the spatial variability of geomorphological characteristics of stream channels and associated streambed properties can affect many biogeochemical processes. In agricultural streams of the midwestern USA, it is not known how geomorphological variability affects sediment denitrification rates, a potentially important loss mechanism for N. Sediment denitrification was measu...

Over much of the ocean’s surface, productivity and growth are limited by a scarcity of bioavailable nitrogen. Sedimentary 15N records spanning the last deglaciation suggest marked shifts in the nitrogen cycle during this time, but the quantification of these changes has been hindered by the complexity of nitrogen isotope cycling. Herewepresent a database of 15N in sediments throughout the world...