The denitrification process profoundly affects soil nitrogen (N) availability and generates its byproduct, nitrous oxide, as a potent greenhouse gas. There are large uncertainties in predicting global denitrification because its controlling factors remain elusive. In this study, we compiled 4301 observations of denitrification rates across a variety of terrestrial ecosystems from 214 papers published in the literature. The averaged denitrification rate was 3516.3 ± 91.1 µg N kg soil day . The highest denitrification rate was 4242.3 ± 152.3 µg N kg soil day under humid subtropical climates, and the lowest was 965.8 ± 150.4 µg N kg under dry climates. The denitrification rate increased with temperature, precipitation, soil carbon and N contents, as well as microbial biomass carbon and N, but decreased with soil clay contents. The variables related to soil N contents (e.g., nitrate, ammonium, and total N) explained the variation of denitrification more than climatic and edaphic variables (e.g., mean annual temperature (MAT), soil moisture, soil pH, and clay content) according to structural equation models. Soil microbial biomass carbon, which was influenced by soil nitrate, ammonium, and total N, also strongly influenced denitrification at a global scale. Collectively, soil N contents, microbial biomass, pH, texture, moisture, and MAT accounted for 60% of the variation in global denitrification rates. The findings suggest that soil N contents and microbial biomass are strong predictors of denitrification at the global scale.
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http://dx.doi.org/10.1111/gcb.16066 | DOI Listing |
J Environ Manage
December 2024
Faculty of Science and Technology, Norwegian University of Life Sciences, P.O. Box 5003, Aas, 1430, Norway.
Primary sludge can serve as an internal carbon source for denitrification in wastewater treatment plants (WWTPs). This study explores the use of alkaline treatment to produce a fermentation broth from primary sludge, which predominantly contains short-chain volatile fatty acids (VFAs), with acetic acid and propionic acid making up over 65% of the total VFAs. The performance of this fermentation broth as a sole carbon source for denitrification was compared with that of sodium acetate, acetic acid, methanol, and ethanol in both biofilm and activated sludge systems.
View Article and Find Full Text PDFJ Environ Manage
December 2024
Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; Department of Ecological Sciences and Engineering, Chongqing University, Chongqing, 400045, China. Electronic address:
In wetlands, hydrological conditions drive plant community distribution, forming vegetation zones with plant species and material cycling. This mediates nitrogen migration and NO emissions within wetlands. Five vegetation zones in a large wetland were studied during flooding and drought periods.
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
December 2024
School of Environment and Ecology, Jiangnan University, Wuxi, 214122, China.
Invasive alien plants pose a great threat to local plants and ecosystems. How to effectively alleviate this hazard is an unresolved issue. This study explored the carbon release characteristics of an invasive plant Spartina alterniflora and evaluated the ability of nitrogen removal from shrimp culture wastewater through constructing seawater wetland.
View Article and Find Full Text PDFHuan Jing Ke Xue
January 2025
Wuhan Center, China Geological Survey (Central South China Innovation Center for Geosciences), Wuhan 430205, China.
Nitrate pollution in water bodies is a worldwide environmental problem, and identifying the sources of nitrate is of great significance to guarantee the sustainable use of water resources. A variety of water chemistry indicators and nitrate nitrogen and oxygen isotopes (N-NO and O-NO) were used to analyze the water chemistry characteristics of water bodies in Shiyan to identify the sources of nitrate in the water bodies and to calculate the contribution rate of nitrate from different pollution sources of the water bodies using the SIMMR model. The results showed that the hydrochemical types of surface water and groundwater in the study area were dominated by the HCO-Ca·Mg type, and the formation of nitrate in the water body was mainly affected by nitrification, with non-obvious denitrification.
View Article and Find Full Text PDFWater Res X
January 2025
Qinhuangdao Huaheng Biological Limited Company, Qinhuangdao, 066000, China.
A full-scale simultaneous partial nitrification, anaerobic ammonia oxidation (anammox), and denitrification (SNAD) reactor was initiated to address the problem of high energy consumption for the treatment of low C/N wastewater. The SNAD system achieved a nitrogen removal rate of 0.9 kg/(m·d) at an influent NH₄-N concentration of 500 mg/L after 450 days of stable operation.
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