The spatial variability exhibited by soil denitriflcation rates is high. As is typical for natural denitriflcation rate measurements, the individual rates of most samples of a given data set are low; however, a few samples often exhibit extremely high rates. Such data are characterized by highly skewed sample frequency distributions. This study was initiated to investigate the underlying mechan...

Nanoscale zero valent iron (NZVI) based microbial denitrification has been demonstrated to be a promising technology for nitrate removal from groundwater. In this work, a mathematical model is developed to evaluate the performance of this new technology and to provide insights into the chemical and microbial interactions in the system in terms of nitrate reduction, ammonium accumulation and hyd...

Denitrification occurs markedly in rice paddy fields; however, few microbes that are actively involved in denitrification in these environments have been identified. In this study, we used a laboratory soil microcosm system in which denitrification activity was enhanced. DNA and RNA were extracted from soil at six time points after enhancing denitrification activity, and quantitative PCR and cl...

A membrane aerated biofilm reactor (MABR), in which O(2) was supplied from the bottom of the biofilm and NH(4)(+) and organic carbon were supplied from the biofilm surface, was operated at different organic carbon loading rates and intra-membrane air pressures to investigate the occurrence of simultaneous chemical oxygen demand (COD) removal, nitrification and denitrification. The spatial distr...

A heterotrophic/biofilm-electrode autotrophic denitrification reactor (HAD-BER) was developed to improve denitrification efficiency and reduce the consumption of organic carbon source. Maximum nitrate removal efficiency of 99.9% was gained under the optimum current density of 200 mA/m(2). The number of heterotrophic denitrification bacteria (HDB) 2.0 × 10(5) and hydrogen autotrophic denitrifica...

Human activities have greatly increased the availability of bioactive nitrogen and, consequently, altered cycle in riverine systems. Here, we studied denitrification rates and denitrifiers river sediment their relationships with aquatic physicochemical variables along a gradient human-disturbance intensity subtropical stream China. We used high-throughput sequencing to characterize denitrifying...

Human activity is accelerating changes in biotic communities worldwide. Predicting impacts of these changes on ecosystem services such as denitrification, a process that mitigates the consequences of nitrogen pollution, remains one of the most important challenges facing ecologists. Wetlands especially are valued as important sites of denitrification, and wetland plants are expected to have dif...

N2O production from denitrification in soils contributes to the enhanced greenhouse effect and the destruction of the stratospheric ozone. Ungulate grazing affects denitrification and the production of N2O. The short-term effect of grazing on denitrification and N2O production has been examined in several grassland ecosystems. However, the effects of long-term grazing have rarely been studied. ...

Observations of gas-phase HNO3 and N2O in the polar stratosphere from the Michelson Interferometer for Passive Atmospheric Sounding aboard the ENVISAT satellite (MIPAS-E) were made during the cold Arctic winter of 2002/2003. Vortex temperatures were unusually low in early winter and remained favourable for polar stratospheric cloud formation and denitrification until mid-January. MIPAS-E observ...