Microbial transformations of nitrification and denitrification are the main sources of nitrous oxide (N2O) from soils. Relative contributions of both processes to N2O emissions were estimated on an agricultural soil using 15N isotope tracers (15NH4+ or 15NO3-), for a 10-day batch experiment. Under unsaturated and saturated conditions, both processes were significantly involved in N2O production. Under unsaturated conditions, 60% of N-N2O came from nitrification, while denitrification contributed around 85-90% under saturated conditions. Estimated nitrification rates were not significantly different whatever the soil moisture content, whereas the proportion of nitrified N emitted as N2O changed from 0.13 to 2.32%. In coherence with previous studies, we interpreted this high value as resulting from the decrease in O2 availability through the increase in soil moisture content. It thus appears that, under limiting aeration conditions, some values for N2O emissions through nitrification could be underestimated.
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http://dx.doi.org/10.1016/j.envpol.2006.02.005 | DOI Listing |
Water Res X
May 2025
School of Environmental Science and Engineering, Tianjin University, Tianjin 300072, PR China.
Widespread polyethylene terephthalate microplastics (PET MPs) have played unintended role in nitrous oxide (NO) turnovers (i.e., production and consumption) at wastewater treatment plants (WWTPs).
View Article and Find Full Text PDFPlant Cell Environ
January 2025
College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China.
Nano-selenium fertilizers can promote plant growth and nitrogen availability. However, little information is available on the effects of nano-selenium on tea leaf quality, soil nutrient availability and associated microbe-driven mechanisms. This study examined the effects of nano-selenium on the tea leaf quality and soil nitrogen cycling in 20-year-old tea plantations when the leaves were sprayed with ammonium or nitrate.
View Article and Find Full Text PDFEcotoxicol Environ Saf
January 2025
College of Tropical Agriculture and Forestry, Hainan University, Haikou 570228, China; School of Breeding and Multiplication (Sanya Institute of Breeding and Multiplication), Hainan University, Sanya 572025, China.
Soil nitrogen (N) transformations control N availability and plant production and pose environmental concerns when N is lost, raising issues such as soil acidification, water contamination, and climate change. Former studies suggested that soil N cycling is chiefly regulated by microbial activity; however, emerging evidence indicates that this regulation is disrupted by heavy metal (HM) contamination, which alters microbial communities and enzyme functions critical to N transformations. Environmental factors like soil organic carbon, soil texture, water content, temperature, soil pH, N fertilization, and redox status play significant roles in modulating the response of soil N cycling to HM contamination.
View Article and Find Full Text PDFBioresour Technol
January 2025
Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044 China. Electronic address:
Iron-carbon (Fe-C) based biofilters have shown significant advantages in treating mariculture wastewater by facilitating the mixotrophic heterotrophic nitrification-aerobic denitrification (HNAD) process. However, the effects of Fe-C materials and varying carbon-to-nitrogen (C/N) ratios on N removal and C reduction performance remain insufficiently explored. This study demonstrated that the Fe-C biofilter (R-Fe) achieved significantly higher NO-N removal efficiency (65.
View Article and Find Full Text PDFEnviron Res
January 2025
College of Environment and Climate, Jinan University, Guangzhou, 510632, PR China. Electronic address:
Nitrogen heterocyclic antibiotics (NHAs) pollution poses a significant threat to aquatic ecosystems. Ozonation (O) pretreatment is beneficial for the removal of total nitrogen (TN) in antibiotics by facilitating subsequent biological treatment. However, nitrogen transformation and bacterial community responses when treating NHAs by O-coupled biological processes remain unclear.
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