Nitrous oxide

Micro-nano plastics (MNPs; size < 5 mm), ubiquitous and emerging pollutants, accumulated in the natural environment through various sources, and are likely to interact with nutrients, thereby influencing their biogeochemical cycle. Increasing scientific evidences reveal that MNPs can affect nitrogen (N) cycle processes by affecting biotopes and organisms in the environmental matrix and MNPs biofilms, thus plays a crucial role in nitrous oxide (N2 O) and ammonia (NH3 ) emission. Yet, the mechanism and key processes behind this have not been systematically reviewed in natural environments...

Wastewater treatment is an important source of non-CO2 greenhouse gases (GHGs). However, current quantification of these GHG emissions mainly employs unit-based measurements, where emissions from individual process units are identified, leading to large uncertainties of overall emissions. Here we introduce plant-integrated measurements, where emissions from the whole plant are measured through the off-gas pipelines of the enclosed facility, to quantify methane (CH4 ) and nitrous oxide (N2 O) emissions from an underground municipal wastewater treatment plant (WWTP) in southern China...

Submerged plants affect nitrogen cycling in aquatic ecosystems. However, whether and how submerged plants change nitrous oxide (N2 O) production mechanism and emissions flux remains controversial. Current research primarily focuses on the feedback from N2 O release to variation of substrate level and microbial communities. It is deficient in connecting the relative contribution of individual N2 O production processes (i.e., the N2 O partition). Here, we attempted to offer a comprehensive understanding of the N2 O mitigation mechanism in aquatic ecosystems on the Changjiang River Delta according to stable isotopic techniques, metagenome-assembly genome analysis, and statistical analysis...

The complex interaction between nitrate (NO3 - ) reduction and fermentation is poorly understood when high levels of NO3 - are introduced into anaerobic systems. This study investigated the competitive distribution between conventional denitrification (DEN) and dissimilatory nitrate reduction to ammonium (DNRA) during simultaneous denitrification and fermentation in arrested methanogenesis. Up to 62 % of initial NO3 - (200 mg-N/L) was retained as ammonium through DNRA at a chemical oxygen demand (COD)/N ratio of 25...

We investigated methane (CH4 ) and nitrous oxide (N2 O), two important greenhouse gases (GHGs) emissions using the closed chamber method from a flooded rice field in Brahmaputra valley of Assam, northeast part of India. We tried to understand the factors responsible for the emission and identify appropriate agro-technologies for their mitigation. Various factors like water level, drainage management, soil organic carbon management, crop management, fertilizer amendment, cultivar type etc. affect the GHG production and emission from the flooded rice soil...

Microplastics pollution and climate change are primarily investigated in isolation, despite their joint threat to the environment. Greenhouse gases (GHGs) are emitted during: the production of plastic and rubber, the use and degradation of plastic, and after contamination of environment. This is the first meta-analysis to assess underlying causal relationships and the influence of likely mediators. We included 60 peer-reviewed empirical studies; estimating GHGs emissions effect size and global warming potential (GWP), according to key microplastics properties and soil conditions...

Research on microplastics (MPs) is gaining more attention in the soil environment, but their impact on soil microbiota and related nitrogen processes remains poorly understood. Nitrous oxide (N2 O) is one of the important greenhouse gases of the nitrogen cycle in agricultural soil, which mainly originates from microbial-mediated nitrogen (N) transformation processes. Microplastics can influence soil nitrogen transformation, as well as nitrogen-related functional enzymes and genes, and its enrichment may profoundly affect the N2 O emissions in soil...

Seawater intrusion into freshwater wetlands causes changes in microbial communities and biogeochemistry, but the exact mechanisms driving these changes remain unclear. Here we use a manipulative laboratory microcosm experiment, combined with DNA sequencing and biogeochemical measurements, to tease apart the effects of sulfate from other seawater ions. We examined changes in microbial taxonomy and function as well as emissions of carbon dioxide, methane, and nitrous oxide in response to changes in ion concentrations...

Carbendazim residue has been widely concerned, and nitrous oxide (N2 O) is one of the dominant greenhouse gases. Microbial metabolisms are fundamental processes of removing organic pollutant and producing N2 O. Nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) can change soil abiotic properties and microbial communities and simultaneously affect carbendazim degradation and N2 O emission. In this study, the comprehensive linkages among carbendazim residue, N2 O emission and microbial community after the DMPP application were quantified under different soil moistures...

No abstract text is available yet for this article.

Sulfonamides, quinolones, tetracyclines, and macrolides are the most prevalent classes of antibiotics used in both medical treatment and agriculture. The misuse of antibiotics leads to their extensive dissemination in the environment. These antibiotics can modify the structure and functionality of microbial communities, consequently impacting microbial-mediated nitrogen cycling processes including nitrification, denitrification, and anammox. They can change the relative abundance of nirK/norB contributing to the emission of nitrous oxide, a potent greenhouse gas...

Greenhouse gas (GHG) fluxes from peatland soils are relatively well studied, whereas tree stem fluxes have received far less attention. Simultaneous year-long measurements of soil and tree stem GHG fluxes in northern peatland forests are scarce, as previous studies have primarily focused on the growing season. We determined the seasonal dynamics of tree stem and soil CH4 , N2 O and CO2 fluxes in a hemiboreal drained peatland forest. Gas samples for flux calculations were manually collected from chambers at different heights on Downy Birch (Betula pubescens) and Norway Spruce (Picea abies) trees (November 2020-December 2021) and analysed using gas chromatography...

No abstract text is available yet for this article.

Nitrous oxide (N2O) has been known since the end of the eighteenth century. Today, N2O plays a huge role as a greenhouse gas and an ozone-depleting stratospheric molecule. The main sources of anthropogenic N2O emissions are agriculture, fuel combustion, wastewater treatment, and various industrial processes. By contrast, the contribution of medical N2O to the greenhouse effect appears to be small. The recreational and medical uses of N2O gradually diverged over time. N2O has analgesic and anesthetic effects, making it widely used in modern dentistry and surgery...

Hydroxylamine can disrupt the protein translation process of most reported nitrogen-converting bacteria, and thus hinder the reproduction of bacteria and nitrogen conversion capacity. However, the effect of hydroxylamine on the denitrification ability of strain EN-F2 is unclear. In this study, the cell growth, aerobic denitrification ability, and nitrous oxide (N2 O) emission by Pseudomonas taiwanensis were carefully investigated by addition of hydroxylamine at different concentrations. The results demonstrated that the rates of nitrate and nitrite reduction were enhanced by 2...

The sources and sinks of nitrous oxide, as control emissions to the atmosphere, are generally poorly constrained for most environmental systems. Initial depth-resolved analysis of nitrous oxide flux from observation wells and the proximal surface within a nitrate contaminated aquifer system revealed high subsurface production but little escape from the surface. To better understand the environmental controls of production and emission at this site, we used a combination of isotopic, geochemical, and molecular analyses to show that chemodenitrification and bacterial denitrification are major sources of nitrous oxide in this subsurface, where low DO, low pH, and high nitrate are correlated with significant nitrous oxide production...

No abstract text is available yet for this article.

PURPOSE OF REVIEW: The no-touch technique is an established method to harvest the saphenous vein (NT-SV), which is the most commonly used conduit in coronary artery bypass grafting. Herein, we summarize the foundational evidence, as well as highlight recent innovations and ongoing clinical trials involving NT-SV. RECENT FINDINGS: Through preservation of perivascular tissue for atraumatic handling and omission of manual distension, the NT-SV maintains endothelial nitrous oxide synthase levels and experiences less vascular smooth muscle cell activation, which translates to slower progression of atherosclerosis and less size mismatch of the graft and target vessel...

Forest soils are an important source of nitrous oxide (N2 O), however, field observations of N2 O emission have often exhibited large variabilities when compared with managed agricultural lands. In the last decade, the number of forest N2 O studies has increased more than tenfold, but only few of them have looked into the interannual flux variabilities from regional scale. Here, we have collected 30 long-term N2 O monitoring studies (≥ 2 years) based on global database, and extracted variabilities (VARFlux ) as well as relative variabilities (VAR% , in proportions) of annual N2 O fluxes...

Cover cropping is a promising strategy to improve soil health, but it may also trigger greenhouse gas emissions, especially nitrous oxide (N2 O). Beyond nitrogen (N) availability, cover crop residue decomposition may accelerate heterotrophic respiration to limit soil O2 availability, hence promote N2 O emissions from denitrification under sub-optimal water-filled pore space (WFPS) conditions that are typically not conducive to large N2 O production. We conducted a 21-day incubation experiment to examine the effects of contrasting cover crop residue (grass vs legume) decomposition on soil O2 and biogeochemical changes to influence N2 O and CO2 emissions from 15 N labeled fertilized soils under 50% and 80% WFPS levels...