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https://www.readbyqxmd.com/read/27913871/n2o-emission-characteristics-and-its-affecting-factors-in-rain-fed-potato-fields-in-wuchuan-county-china
#1
Liwei Wang, Cheng Wang, Zhihua Pan, Hui Xu, Lin Gao, Peiyi Zhao, Zhiqiang Dong, Jingting Zhang, Guohui Cui, Sen Wang, Guolin Han, Hui Zhao
Representing an important greenhouse gas, nitrous oxide (N2O) emission from cultivated land is a hot topic in current climate change research. This study examined the influences of nitrogen fertilisation, temperature and soil moisture on the ammonia monooxygenase subunit A (amoA) gene copy numbers and N2O emission characteristics. The experimental observation of N2O fluxes was based on the static chamber-gas chromatographic method. The ammonia-oxidising bacteria (AOB) and ammonia-oxidising archaea (AOA) gene copy numbers in different periods were measured by real-time polymerase chain reaction (PCR)...
December 3, 2016: International Journal of Biometeorology
https://www.readbyqxmd.com/read/27905393/nitrous-oxide-as-a-function-of-oxygen-and-archaeal-gene-abundance-in-the-north-pacific
#2
Mark Trimmer, Panagiota-Myrsini Chronopoulou, Susanna T Maanoja, Robert C Upstill-Goddard, Vassilis Kitidis, Kevin J Purdy
Oceanic oxygen minimum zones are strong sources of the potent greenhouse gas N2O but its microbial source is unclear. We characterized an exponential response in N2O production to decreasing oxygen between 1 and 30 μmol O2 l(-1) within and below the oxycline using (15)NO2(-), a relationship that held along a 550 km offshore transect in the North Pacific. Differences in the overall magnitude of N2O production were accounted for by archaeal functional gene abundance. A one-dimensional (1D) model, parameterized with our experimentally derived exponential terms, accurately reproduces N2O profiles in the top 350 m of water column and, together with a strong (45)N2O signature indicated neither canonical nor nitrifier-denitrification production while statistical modelling supported production by archaea, possibly via hybrid N2O formation...
December 1, 2016: Nature Communications
https://www.readbyqxmd.com/read/27898802/nutrient-cycling-in-grassed-roadside-ditches-and-lawns-in-a-suburban-watershed
#3
Lauren E McPhillips, Peter M Groffman, Rebecca L Schneider, M Todd Walter
Roadside ditches are ubiquitous in developed landscapes. They are designed to route water from roads for safety, with little consideration of water quality or biogeochemical implications in ditch design and minimal data on environmental impacts. We hypothesize that periodic saturation and nutrient influxes may make roadside ditches hotspots for nitrogen (N) removal via denitrification as well as biological production of the greenhouse gases (GHGs) nitrous oxide (NO), methane (CH), and carbon dioxide (CO). Research sites included 12 grassed ditches and adjacent lawns with varying fertilization in a suburban watershed in central New York, where lawns represented a reference with similar soils as ditches but differing hydrology...
November 2016: Journal of Environmental Quality
https://www.readbyqxmd.com/read/27898801/reduction-of-methane-emission-during-slurry-storage-by-the-addition-of-effective-microorganisms-and-excessive-carbon-source-from-brewing-sugar
#4
Mohd Saufi B Bastami, Davey L Jones, David R Chadwick
Storing livestock manure is the primary stage of manure management where microbial processes and chemical reactions result in the release of methane (CH), nitrous oxide (NO), ammonia (NH), and carbon dioxide (CO). This study examined the reduction of CH emissions from slurry storage under two temperatures (cool [10°C] and warm [30°C]) when a glucose-rich substrate (brewing sugar) and activated effective microorganisms were applied at 10% (w/w) and 5% (v/w), respectively. Brewing sugar addition influenced microbial anaerobic respiration, resulting in a reduction of slurry pH to <5...
November 2016: Journal of Environmental Quality
https://www.readbyqxmd.com/read/27898795/corn-nitrogen-management-influences-nitrous-oxide-emissions-in-drained-and-undrained-soils
#5
Fabián G Fernández, Rodney T Venterea, Karina P Fabrizzi
To date, no studies have evaluated nitrous oxide (NO) emissions of a single versus a split-nitrogen (N) fertilizer application under different soil drainage conditions for corn ( L.). The objective of this study was to quantify season-long cumulative NO emissions, N use efficiency, and soil N dynamics when corn received a recommended N rate as single or split-N application in Minnesota soils with and without tile drainage over two growing seasons. Preplant urea was broadcast incorporated, and in-season split-N was broadcast as urea plus urease inhibitor...
November 2016: Journal of Environmental Quality
https://www.readbyqxmd.com/read/27898794/greenhouse-gas-emissions-from-solid-and-liquid-organic-fertilizers-applied-to-lettuce
#6
Phasita Toonsiri, Stephen J Del Grosso, Arina Sukor, Jessica G Davis
Improper application of nitrogen (N) fertilizer and environmental factors can cause the loss of nitrous oxide (NO) to the environment. Different types of fertilizers with different C/N ratios may have different effects on the environment. The focus of this study was to evaluate the effects of environmental factors and four organic fertilizers (feather meal, blood meal, fish emulsion, and cyano-fertilizer) applied at different rates (0, 28, 56, and 112 kg N ha) on NO emissions and to track CO emissions from a lettuce field ( L...
November 2016: Journal of Environmental Quality
https://www.readbyqxmd.com/read/27898789/nitrous-oxide-emissions-from-open-lot-cattle-feedyards-a-review
#7
Heidi M Waldrip, Richard W Todd, David B Parker, N Andy Cole, C Alan Rotz, Kenneth D Casey
Nitrous oxide (NO) emissions from concentrated animal feeding operations, including cattle feedyards, have become an important research topic. However, there are limitations to current measurement techniques, uncertainty in the magnitude of feedyard NO fluxes, and a lack of effective mitigation methods. The objective of this review was to assess NO emission from cattle feedyards, including comparison of measured and modeled emission rates, discussion of measurement methods, and evaluation of mitigation options...
November 2016: Journal of Environmental Quality
https://www.readbyqxmd.com/read/27898788/field-nitrogen-losses-induced-by-application-timing-of-digestate-from-dairy-manure-biogas-production
#8
Emily A Schwager, Andrew C VanderZaag, Claudia Wagner-Riddle, Anna Crolla, Chris Kinsley, Ed Gregorich
Anaerobic digestion of dairy manure has environmental benefits, but the impact of effluent (i.e., digestate [DG]) application on environmental nitrogen (N) losses from soils has not been well quantified. Our objective was to evaluate how field application of DG affected nitrous oxide (NO) emissions and nitrate (NO) leaching compared with raw dairy manure (RM) in spring versus fall applications. We measured N losses year-round for 2.5 yr in silage corn on tile-drained clay soil in Alfred, Ontario, Canada. Treatments were: digestate applied in spring (DS) and fall (DF), raw dairy manure applied in spring (RS) and fall (RF), urea applied in spring, and a control...
November 2016: Journal of Environmental Quality
https://www.readbyqxmd.com/read/27898786/the-extent-of-manure-removal-from-storages-and-its-impact-on-gaseous-emissions
#9
N M Ngwabie, R J Gordon, A VanderZaag, K Dunfield, A Sissoko, C Wagner-Riddle
Manure remaining in storage due to incomplete removal is a source of microbial inoculum that may affect methane (CH), nitrous oxide (NO), and ammonia (NH) emissions during subsequent storage. Manure removal was studied by loading fresh manure into outdoor concrete tanks (10.6 m) that contained previously stored manure (inoculum) at six levels (0, 5, 10, 15, 20, and 25%, with 0% representing an empty tank). Emissions were continuously measured for 6-mo storage periods (warm and cold seasons) using flow-through chambers...
November 2016: Journal of Environmental Quality
https://www.readbyqxmd.com/read/27898774/effects-of-feeding-encapsulated-nitrate-to-beef-cattle-on-ammonia-and-greenhouse-gas-emissions-from-their-manure-in-a-short-term-manure-storage-system
#10
Chanhee Lee, Rafael C Araujo, Karen M Koenig, Michael L Hile, Eileen E Fabian-Wheeler, Karen A Beauchemin
A study was conducted to investigate effects of feeding encapsulated nitrate (EN) to beef cattle on ammonia (NH) and greenhouse gas emissions from their manure. Eight beef heifers were randomly assigned to diets containing 0 (control), 1, 2, or 3% EN (55% forage dry matter; EN replaced encapsulated urea in the control diet and therefore all diets were iso-nitrogenous) in a replicated 4 × 4 Latin square design. Urine and feces collected from individual animals were reconstituted into manure and incubated over 156 h using a steady-state flux chamber system to monitor NH, methane (CH), carbon dioxide (CO), and nitrous oxide (NO) emissions...
November 2016: Journal of Environmental Quality
https://www.readbyqxmd.com/read/27895629/genome-wide-discovery-of-putative-srnas-in-paracoccus-denitrificans-expressed-under-nitrous-oxide-emitting-conditions
#11
Hannah Gaimster, Lisa Chalklen, Mark Alston, John T Munnoch, David J Richardson, Andrew J Gates, Gary Rowley
Nitrous oxide (N2O) is a stable, ozone depleting greenhouse gas. Emissions of N2O into the atmosphere continue to rise, primarily due to the use of nitrogen-containing fertilizers by soil denitrifying microbes. It is clear more effective mitigation strategies are required to reduce emissions. One way to help develop future mitigation strategies is to address the currently poor understanding of transcriptional regulation of the enzymes used to produce and consume N2O. With this ultimate aim in mind we performed RNA-seq on a model soil denitrifier, Paracoccus denitrificans, cultured anaerobically under high N2O and low N2O emitting conditions, and aerobically under zero N2O emitting conditions to identify small RNAs (sRNAs) with potential regulatory functions transcribed under these conditions...
2016: Frontiers in Microbiology
https://www.readbyqxmd.com/read/27888548/effects-of-seasonality-transport-pathway-and-spatial-structure-on-greenhouse-gas-fluxes-in-a-restored-wetland
#12
Gavin McNicol, Cove S Sturtevant, Sara H Knox, Iryna Dronova, Dennis D Baldocchi, Whendee L Silver
Wetlands can influence global climate via greenhouse gas (GHG) exchange of carbon dioxide (CO2 ), methane (CH4 ), and nitrous oxide (N2 O). Few studies have quantified the full GHG budget of wetlands due to the high spatial and temporal variability of fluxes. We report annual open-water diffusion and ebullition fluxes of CO2 , CH4 , and N2 O from a restored emergent marsh ecosystem. We combined these data with concurrent eddy-covariance measurements of whole-ecosystem CO2 and CH4 exchange to estimate GHG fluxes and associated radiative forcing effects for the whole wetland, and separately for open-water and vegetated cover types...
November 26, 2016: Global Change Biology
https://www.readbyqxmd.com/read/27886586/nitrous-oxide-from-moving-bed-based-integrated-fixed-film-activated-sludge-membrane-bioreactors
#13
Giorgio Mannina, Marco Capodici, Alida Cosenza, Daniele Di Trapani, Vito Armando Laudicina, Hallvard Ødegaard
The present paper reports the results of a nitrous oxide (N2O) production investigation in a moving bed based integrated fixed film activated sludge (IFAS) membrane bioreactor (MBR) pilot plant designed in accordance with the University of Cape Town layout for biological phosphorous removal. Gaseous and liquid samples were collected in order to measure the gaseous as well as the dissolved concentration of N2O. Furthermore, the gas flow rate from each reactor was measured and the gas flux was estimated. The results confirmed that the anoxic reactor represents the main source of nitrous oxide production...
November 22, 2016: Journal of Environmental Management
https://www.readbyqxmd.com/read/27885780/synthesis-and-investigation-of-advanced-energetic-materials-based-on-bispyrazolylmethanes
#14
Dennis Fischer, Jennifer L Gottfried, Thomas M Klapötke, Konstantin Karaghiosoff, Jörg Stierstorfer, Tomasz G Witkowski
Herein we present the preparation and characterization of three new bispyrazolyl-based energetic compounds with great potential as explosive materials. The reaction of sodium 4-amino-3,5-dinitropyrazolate (5) with dimethyl iodide yielded bis(4-amino-3,5-dinitropyrazolyl)methane (6), which is a secondary explosive with high heat resistance (Tdec =310 °C). The oxidation of this compound afforded bis(3,4,5-trinitropyrazolyl)methane (7), which is a combined nitrogen- and oxygen-rich secondary explosive with very high theoretical and estimated experimental detonation performance (Vdet (theor)=9304 m s(-1) versus Vdet (exp)=9910 m s(-1) ) in the range of that of CL-20...
November 25, 2016: Angewandte Chemie
https://www.readbyqxmd.com/read/27878774/a-model-for-determination-of-operational-conditions-for-successful-shortcut-nitrification
#15
Xiaoguang Liu, Mingu Kim, George Nakhla
Accumulation of nitrite in shortcut nitrification is influenced by several factors including dissolved oxygen concentration (DO), pH, temperature, free ammonia (FA), and free nitrous acid (FNA). In this study, a model based on minimum dissolved oxygen concentration (DOmin), minimum/maximum substrate concentration (Smin and Smax), was developed. The model evaluated the influence of pH (7-9), temperature (10-35 °C), and solids retention time (SRT) (5 days-infinity) on MSC values. The evaluation was conducted either by controlling total ammonium nitrogen (TAN) or total nitrite nitrogen (TNN), concentration at 50 mg N/L while allowing the other to vary from 0 to 1000 mg N/L...
November 23, 2016: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/27871590/does-nitrous-oxide-labor-analgesia-influence-the-pattern-of-neuraxial-analgesia-usage-an-impact-study-at-an-academic-medical-center
#16
Lesley E Bobb, Michaela K Farber, Catherine McGovern, William Camann
STUDY OBJECTIVE: To compare the rate of epidural use before and after the implementation of nitrous oxide (N2O). DESIGN: Data were obtained from a nursing database of N2O usage and our obstetric anesthesia database. We compared 8 months before and 8 months after the introduction of N2O. It was available 24 h/d, 7 d/wk, consistent with neuraxial analgesia availability. Epidural utilization before and after introduction of N2O was compared using χ(2) analysis. SETTING: Labor and delivery floor...
December 2016: Journal of Clinical Anesthesia
https://www.readbyqxmd.com/read/27869553/radiation-induced-chemical-reactions-in-hydrogel-of-hydroxypropyl-cellulose-hpc-a-pulse-radiolysis-study
#17
Shinichi Yamashita, Jun Ma, Jean-Louis Marignier, Akihiro Hiroki, Mitsumasa Taguchi, Mehran Mostafavi, Yosuke Katsumura
We performed studies on pulse radiolysis of highly transparent and shape-stable hydrogels of hydroxypropyl cellulose (HPC) that were prepared using a radiation-crosslinking technique. Several fundamental aspects of radiation-induced chemical reactions in the hydrogels were investigated. With radiation doses less than 1 kGy, degradation of the HPC matrix was not observed. The rate constants of the HPC composing the matrix, with two water decomposition radicals [hydroxyl radical ((•)OH) and hydrated electron ([Formula: see text])] in the gels, were determined to be 4...
November 21, 2016: Radiation Research
https://www.readbyqxmd.com/read/27865665/enhanced-volatile-fatty-acid-production-from-excess-sludge-by-combined-free-nitrous-acid-and-rhamnolipid-treatment
#18
Qing-Lian Wu, Wan-Qian Guo, Xian Bao, He-Shan Zheng, Ren-Li Yin, Xiao-Chi Feng, Hai-Chao Luo, Nan-Qi Ren
VFA production from excess sludge (ES) was greatly enhanced by a low-cost and high-efficient treatment: 0.67mg/L free nitrous acid (FNA) pretreatment combined with 0.04g/g TSS rhamnolipid (RL) addition (FNA+RL), which significantly shortened fermentation time to 3days and increased VFA production to 352.26mgCOD/g VSS (5.42 times higher than raw ES). Propionic and acetic acids were the two leading components (71.86% of the total VFA). Mechanism investigation manifested FNA+RL improved the biodegradability of ES, achieved positive synergetic effect on solubilization, hydrolysis and acidification efficiencies, and inhibited methanation...
October 31, 2016: Bioresource Technology
https://www.readbyqxmd.com/read/27864152/the-flavinyl-transferase-apbe-of-pseudomonas-stutzeri-matures-the-nosr-protein-required-for-nitrous-oxide-reduction
#19
Lin Zhang, Christian Trncik, Susana L A Andrade, Oliver Einsle
The copper-containing enzyme nitrous oxide reductase (N2OR) catalyzes the transformation of nitrous oxide (N2O) to dinitrogen (N2) in microbial denitrification. Several accessory factors are essential for assembling the two copper sites CuA and CuZ and for maintaining their activity. In particular, the deletion of either the transmembrane iron-sulfur flavoprotein NosR or the periplasmic protein NosX, a member of the ApbE family, abolishes N2O respiration. Here we demonstrate through biochemical and structural studies that the ApbE protein from Pseudomonas stutzeri, where the nosX gene is absent, is a monomeric FAD-binding protein that can serve as the flavin donor for NosR maturation via covalent flavinylation of a threonine residue...
November 15, 2016: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/27862728/an-energetic-triazolo-1-2-4-triazine-and-its-n-oxide
#20
Davin G Piercey, David E Chavez, Brian L Scott, Greg H Imler, Damon A Parrish
The reaction of 3-amino-5-nitro-1,2,4-triazole with nitrous acid produces the corresponding diazonium salt. When the diazonium salt is treated with nitroacetonitrile, a subsequent condensation and cyclization reaction occurres to produced 4-amino-3,7-dinitrotriazolo-[5,1-c][1,2,4] triazine (DPX-26). X-ray crystallographic analysis shows that the DPX-26 has a density of 1.86 g cm(-3) , while it is calculated to have a heat of formation of 398.3 kJ mol(-1) . DPX-26 is predicted to approach the explosive performance of RDX but displays significantly better safety properties...
November 9, 2016: Angewandte Chemie
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