Consulta: subjectFacets:"Denitrification"
Registros recuperados: 25
Data/hora: 01/06/2024 05:17:12

Effect of cycle time and airflow in biological nitrogen removal from poultry slaughterhouse wastewater using sequencing batch reactor
Provedor de dados: 70
Autores: Lopes,Carla L.; Mees,Juliana B. R.; Sene,Luciane; Carvalho,Karina Q. de; Christ,Divair; Gomes,Simone D.
This study aimed to evaluate the influence of airflow (0.25, 0.50 and 0.75 L.L-1.min-1) and cycle time (10.45 h, 14.25 h and 17.35 h) on a sequencing batch reactor (SBR) performance in promoting nitrification and denitrification of poultry slaughterhouse wastewater. The operational stages included feeding, aerobic and anoxic reactions, sedimentation and discharge. SBR was operated in a laboratory scale with a working volume of 4 L, keeping 25% of biomass retained inside the reactor as inoculum for the next batch. In the anoxic stage, C: N ratio was maintained between 5 and 6 by adding cassava starch wastewater. A factorial design (22) with five repetitions was designed at the central point to evaluate the influence of cycle time and airflow on total...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Nitrification; Denitrification; Response surface methodology; Fluorescent in situ hybridization.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162015000300567

EFFECT OF AERATION AND RECIRCULATION IN THE REMOVAL OF NITROGEN AND CHEMICAL OXYGEN DEMAND FROM SANITARY SEWAGE IN A STRUCTURED BED REACTOR
Provedor de dados: 70
Autores: Leick,Sheilla A.; Oliveira,João G B. De; Tavares,Karoline A.; Lopes,Deize D.; Barana,Ana C.
ABSTRACT This study aimed to evaluate a structured bed reactor with intermittent aeration in the simultaneous removal of Chemical Oxygen Demand (COD) and Total Nitrogen (TN) from sanitary sewage. The reactor was operated for 339 days with a Hydraulic Retention Time (HRT) of 12 hours, temperature of 30 ± 1°C and continuous feeding. Nine trials were carried out in which three different effluent recirculation flow (Qr), 3, 2 and 1 time the incoming flow, were evaluated in three different aeration times, of 1h, 2h, and 3h, in 3 hour cycles. The results showed that different recirculation flows and aeration times did not influence the removal of COD, which reached 89%±12. It was observed that the efficiency of TN removal was higher in the tests with higher...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bioreactor; Wastewater; Denitrification; Nitrification; SND (Simultaneous Nitrification and Denitrification).
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162017000601236

Application of response surface methodology to study the biological removal of nitrogen from effluent of cattle slaughterhouse in a sequencing batch reactor
Provedor de dados: 70
Autores: Lima,Adriana N. de; Gomes,Benedito M.; Gomes,Simone D.; Carvalho,Karina Q. de; Christ,Divair.
The aim of this study was to evaluate the efficiency of a sequencing batch reactor (SBR) on biological removal of nitrogen from cattle slaughterhouse wastewater by nitrification/denitrification processes. The effects of initial concentration of ammoniacal nitrogen were investigated at 100; 150 and 200 mg L-1 and air flow rate at 0.125; 0.375 and 0.625 L min¹ Lreactor-1 on the nitrogen compounds removal, by a Central Composite Rotational Design (CCRD) configuration. There were variations from 9.2 to 94.9%, 4.0 to 19.6% and 20.8 to 92.0% in the conversion of ammoniacal nitrogen to nitrate and nitrite concentration and removal of total nitrogen, respectively. The increase of air flow rate and decrease of the initial concentration of ammoniacal nitrogen...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Nitrification; Denitrification; Central composite rotational design.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162014000200017

Nitrogen cycling in sub-oxic water colmns
Provedor de dados: 72
Autores: Dalsgaard,Tage; Thamdrup,Bo; Mark Jensen,Marlene.
The current knowledge about nitrogen removal processes in suboxic water columns will be reviewed. The most recent development in the understanding of these processes is the documentation of anaerobic ammonium oxidation with nitrite (anammox) in these areas, and the balance between the traditional denitrification and anammox will be in focus.
Tipo: Journal article
Palavras-chave: Denitrification; Anammox; Water column; Nitrogen removal.
Ano: 2006
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382006000300004

Oxygen deficiency in the north indian ocean
Provedor de dados: 72
Autores: Naqvi,S.W.A.
The Indian Ocean contains one of the oceans' most pronounced oxygen minimum zones (OMZ), which, anomalously, is the most intense in the northwestern sector (Arabian Sea). It also contains the majority of the area of oceanic continental margins in contact with oxygen-depleted waters. Impacts of the oxygen deficiency on regional biogeochemistry, especially anaerobic nitrogen transformations, are described. A comparison of the perennial, mesopelagic OMZ in the open Northwestern Indian Ocean is made with a shallower oxygen deficient system that develops seasonally (during late summer and autumn) over the western Indian shelf. The latter appears to have intensified in recent years presumably due to anthropogenic nutrient loading from land.
Tipo: Journal article
Palavras-chave: Indian Ocean; Nitrogen cycling; Denitrification; N2O; Eutrophication.
Ano: 2006
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382006000300011

NON-SYMBIOTIC NITROGEN FIXATION, NET NITROGEN MINERALIZATION AND DENITRIFICATION IN EVERGREEN FORESTS OF CHILOÉ ISLAND, CHILE: A COMPARISON WITH OTHER TEMPERATE FORESTS
Provedor de dados: 73
Autores: Pérez,C.A.; Carmona,M.R.; Armesto,J.J.
Temperate forests in southern Chile offer unique opportunities for studying biogeochemical cycles in the absence of industrial air pollution. Here we compare three important fluxes of the nitrogen (N) cycle in temperate forests of southern Chile, non-symbiotic N fixation, net N mineralization and denitrification, with data from northern temperate forests more affected by air pollution. We studied five evergreen, old-growth forests and one second-growth forest in Chiloé Island, southern Chile. Non-symbiotic N fixation in the litter layer, mineral soil and coarse woody debris was estimated by the acetylene reduction technique. In situ net-N mineralization in the upper mineral soil layer was assessed by the buried bag method. Denitrification rates of mineral...
Tipo: Journal article
Palavras-chave: Denitrification; Nitrogen cycle; Nitrogen fixation; Temperate forests; Unpolluted forests.
Ano: 2003
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-66432003000100005

Response of sedimentary processes to cyanobacteria loading
Provedor de dados: 5
Autores: Zilius, Mindaugas; De Wit, Rutger; Bartoli, Marco.
Sedimentation of pelagic cyanobacteria in dystrophic freshwater and oligohaline lagoons results in large inputs of labile organic matter (OM) to the benthos. We used an experimental approach to study the short-term impact of such phenomena on the benthic microbial community metabolism and on the nitrogen (N) fluxes across the sediment-water interface. We hypothesized an increase of respiratory activity, including N loss via denitrification and its recycling to the water column. Our results show that the incorporation within sediments of the settled bloom increases benthic bacterial activities. This is coupled to large DON and NH4+ effluxes, and to a comparatively smaller increase of N-2 production, while no significant effects were detected for the benthic...
Tipo: Text
Palavras-chave: Cyanobacteria; Organic matter; Sediments; Benthic metabolism; DON; Denitrification.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00354/46504/74457.pdf

Cycle de l'azote à l' interface eau-sédiment dans le Bassin d'Arcachon : rôle des bactéries dans les processus de perte en azote (nitrification-dénitrification)
Provedor de dados: 5
Autores: Riou, Stéphane Alain.
Bacterial nitrification and denitrification were studied in the sediments of the Bassin d'Arcachon, a macrotidallagoon located in the Southwestern Atlantic French coast colonized by extensive Zostera noltii  meadows. Nitrifiers were enumerated by MPN method. Densities were law : from 102 to 104 bacteria per ml of sediment presenting an increase during winter. Nitrifying activities were measured by NH4+  accumulation N-serve block technique. Activities were ranged from 0 to 90 µmol m-2 h-1 and nitrification represented 120-140 mmol m-2 yr-1 for intertidal sediments. The 15N  isotope pairing technique was applied to sediment samples from the whole bay for determining the denitrification rates. Average rates were 10-20 µmol m·2 h-1 with a maximum of 75 µmol...
Tipo: Text
Palavras-chave: Nitrification; Dénitrification; Sédiment; Zostera noltii; Lagune; NPP; N6SERVE; 15N; Nitrification; Denitrification; Sediment; Zostera noltii; Marine laboon; MPN; N-serve; 15N.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/00443/55439/56959.pdf

Glacial-interglacial modulation of the marine nitrogen cycle by high-latitude O-2 supply to the global thermocline
Provedor de dados: 5
Autores: Galbraith, Ed; Kienast, M; Pedersen, Tf; Calvert, Se.
An analysis of sedimentary nitrogen isotope records compiled from widely distributed marine environments emphasizes the global synchrony of denitrification changes and provides evidence for a strong temporal coupling of these variations to changes in nitrogen fixation as previously inferred. We explain the global coherence of these records by a simple physical control on the flux of dissolved oxygen to suboxic zones and the coupling to fixation via the supply of phosphorus to diazotrophs in suitable environments. According to our hypothesis, lower glacial-stage sea surface temperature increased oxygen solubility, while stronger winds in high-latitude regions enhanced the rate of thermocline ventilation. The resultant colder, rapidly flushed thermocline...
Tipo: Text
Palavras-chave: Isotopes; Fixation; Denitrification.
Ano: 2004
URL: https://archimer.ifremer.fr/doc/00229/34026/32421.pdf

Uranium in the Arabian Sea: role of denitrification in controlling its distribution
Provedor de dados: 5
Autores: Rengarajan, R; Sarin, Mm; Krishnaswami, S.
A total of 61 samples, from six vertical profiles between surface and 1800 m from the Arabian Sea, have been analysed for uranium concentration to assess its behaviour in oxic and sub-oxic waters. These samples cover a wide range of dissolved oxygen concentration, from 0.14 to 230 muM. Uranium concentration in most of the samples fall in the range of 3.2 +/- 0.2 mug l(-1). In general, uranium exhibits a conservative behaviour in the Arabian Sea water column and denitrification processes do not seem to influence its abundance. The mean uranium/salinity ratio in waters with dissolved oxygen &lt;2 muM is (9.17 +/- 0.15) x 10(-8) g g(-1), nearly identical to the ratio (9.22 +/- 0.27) x 10(-8) g g(-1) in waters with dissolved oxygen &gt;100 muM and in waters...
Tipo: Text
Palavras-chave: Mer d'Arabie; Uranium; Dénitrification; Niveaux faiblement oxygénés; Arabian Sea; Uranium; Denitrification; Sub-oxic layers.
Ano: 2003
URL: http://archimer.ifremer.fr/doc/00321/43258/42989.pdf

Response to Liu's comments on "The Kuroshio Intermediate Water is the major source of nutrients on the East China Sea continental shelf" by Chen (1996)
Provedor de dados: 5
Autores: Chen, Cta.
Exchanges between the East China Sea (ECS) and the Kuroshio have been recalculated by taking into consideration the intra-annual variation of salinity on the shelf. Flux through the Taiwan Strait, previously unavailable data in the Yellow Sea and in the central and northern ECS, denitrification and ground water fluxes are now also considered. The Kuroshio Intermediate Water remains the major source of nutrients on the East China Sea continental shelf, with slightly more upwelling in the dry season than in the wet season.
Tipo: Text
Palavras-chave: Mer de Chine orientale; Eau intermédiaire du Kuroshio; Upwelling; Bilan de nutriments; Dénitrification; East China Sea; Kuroshio Intermediate Water; Upwelling; Nutrient budgets; Denitrification.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/00325/43654/43220.pdf

New developments in recirculating aquaculture systems in Europe: A perspective on environmental sustainability
Provedor de dados: 5
Autores: Martins, C. I. M.; Eding, E. H.; Verdegem, M. C. J.; Heinsbroek, L. T. N.; Schneider, O.; Blancheton, Jean-paul; Roque D'Orbcastel, Emmanuelle; Verreth, J. A. J.
The dual objective of sustainable aquaculture, i.e., to produce food while sustaining natural resources is achieved only when production systems with a minimum ecological impact are used. Recirculating aquaculture systems (RASs) provide opportunities to reduce water usage and to improve waste management and nutrient recycling. RAS makes intensive fish production compatible with environmental sustainability. This review aims to summarize the most recent developments within RAS that have contributed to the environmental sustainability of the European aquaculture sector. The review first shows the ongoing expansion of RAS production by species and country in Europe. Life cycle analysis showed that feed, fish production and waste and energy are the principal...
Tipo: Text
Palavras-chave: Intensive systems; Ecological impact; Waste; Water re-use; Denitrification.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00021/13190/10273.pdf

Influence of shellfish farming activities on nitrification, nitrate reduction to ammonium and denitrification at the water-sediment interface of the Thau lagoon, France
Provedor de dados: 5
Autores: Gilbert, F; Souchu, Philippe; Bianchi, M; Bonin, P.
The seasonal patterns of nitrification, denitrification and dissimilatory ammonium production (DAP) rates were studied in the sediment of 2 stations in the Thau lagoon (south of France). The station ZA was located within the shellfish farming zone and the station B was the reference site. A marked effect of shellfish fanning on bacterial activities was observed. Spatial differences were associated with discrepancies in the organic content and the reduction state of sediments, i.e. highest reductive processes (denitrification and DAP) were noted in shellfish farming area, whereas the oxidative process (nitrification) was predominant outside the farming zone. At both stations, the DAP activity increased in September (autumn) concomitant with an increase of...
Tipo: Text
Palavras-chave: Shellfish farming; Nitrogen bacterial processes; Nitrification; Nitrate reduction to ammonium; Denitrification; Thau lagoon; Mediterranean Sea; Sediment-water exchanges.
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00070/18145/15697.pdf

Reduction du nitrate dans les sediments marins. Comparaison des activites mesurees in vitro et in situ
Provedor de dados: 5
Autores: Esteves, J; Bonin, P; Blanc, F; Mille, G; Bertrand, J.
In vitro nitrate reduction in hydrocarbon-polluted marine sediments has been studied by flow-through system. By analysing the rate of nitrate comsumption as a function of nitrate concentration the authors determined the Michaelis-Menten kinetics parameters. (km = 330 mu M; vax = 2.0 mu M/g super(-1)/h super(-1). The authors found a value of 60 mu M/m super(-2)/h super(-1) for the rate of in vitro nitrate consumption derived from the above kinetic parameters and from the nitrate concentration in the sediment. In parallel a value of 67.4 mu M/m super(-2)/h super(-1) was found for the rate of nitrate consumption under in situ conditions. The great similarity between both results would favor the in vitro technique as a valid and more convenient one.
Tipo: Text
Palavras-chave: MED; Biogeochemistry; Oil pollution; Methodology; Environmental conditions; Experimental research; Comparative studies; Metabolism; Bacteria; Sediment chemistry; Reduction; Nitrates; Denitrification; Nitrogen cycle.
Ano: 1984
URL: http://archimer.ifremer.fr/doc/1984/acte-979.pdf

First Evidence of Anoxia and Nitrogen Loss in the Southern Canary Upwelling System
Provedor de dados: 5
Autores: Machu, Eric; Capet, Xavier; Estrade, Philippe; Ndoye, S.; Brajard, J.; Baurand, Francois; Auger, P.-a.; Lazar, A.; Brehmer, Patrice.
The northeastern Atlantic hosts the most ventilated subsurface waters of any eastern boundary upwelling system, while coastal upwelling source waters are slightly above hypoxic levels. Anoxic conditions have previously been found offshore inside mesoscale eddies whose core waters undergo oxygen consumption for many months. Based on circumstantial in situ observations this study demonstrates that the Senegalese coastal ocean is subjected to episodic occurrence of zero dissolved oxygen concentration at depth along with elevated nitrite concentration (11 mmol/m3) and nitrate/nitrite deficit to phosphate, thereby indicating severe anoxia and intense nitrogen loss. The anoxic event was associated with a prolonged upwelling relaxation episode in March 2012 and a...
Tipo: Text
Palavras-chave: Oxygen; Canary upwelling system; Anoxia; Denitrification; Shallow continental shelf.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00479/59020/61640.pdf

An experiment on the relative importance of denitrification, nitrate reduction and ammonification in coastal marine sediment
Provedor de dados: 27
Autores: Goeyens, L.; De Vries, R.T.P.; Bakker, J.F.; Helder, W.
Simultaneous determinations of &lt;sup&gt;15&lt;/sup&gt;N-nitrogen gas production, &lt;sup&gt;15&lt;/sup&gt;N-ammonia formation by nitrate reduction and ammonia production from organic nitrogen were carried out after addition of &lt;sup&gt;15&lt;/sup&gt;N-nitrate to anaerobically incubated sediment slurries from a location in the Dutch Wadden Sea. The rate of nitrogen gas production was 1.75 µmol N.cm&lt;sup&gt;-3&lt;/sup&gt; wet sediment.d&lt;sup&gt;-1&lt;/sup&gt;, nitrate reduction to ammonia occurred to a rate of 0.79 µmol N.cm &lt;sup&gt;-3&lt;/sup&gt;.d &lt;sup&gt;-1&lt;/sup&gt; and ammonification at 1.17 µmol N-cm &lt;sup&gt;-3&lt;/sup&gt;.d &lt;sup&gt;-1&lt;/sup&gt;. At the end of the incubation experiment (after 30 h) 63% of the originally added...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ammonia; Biogeochemical cycle; Coastal zone; Denitrification; Nitrates; Nitrogen cycle; Sediments.
Ano: 1987
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3169

15N uptake fom manure and fertilizer sources by three consecutive crops under controlled conditions
Provedor de dados: 90
Autores: Garza,Héctor Mario Quiroga; Delgado,Jorge A.; Wong,José Antonio Cueto; Lindemann,William C.
There are several regions of the world where soil N analysis and/or N budgets are not used to determine how much N to apply, resulting in higher than needed N inputs, especially when manure is used. One such region is the North Central "La Comarca Lagunera", one of the most important dairy production areas of Mexico. We conducted a unique controlled greenhouse study using 15N fertilizer and 15N isotopic-labeled manure that was labeled under local conditions to monitor N cycling and recovery under higher N inputs. The manure-N treatment was applied only once and was incorporated in the soil before planting the first forage crop at an equivalent rate of 30, 60 and 120 Mg ha-1 dry manure. The 15N treatments were equivalent to 120 and 240 kg ha-1 (NH4)2SO4-N...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Denitrification; Nitrogen use efficiency; Annual ryegrass; Salinity; Sudangrass.
Ano: 2009
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832009000500018

Emission of nitrous oxide and carbon dioxide from semi-arid tropical soils in Chiapas México
Provedor de dados: 90
Autores: Ponce-Mendoza,Alejandro; Ceballos-Ramírez,Juan Manuel; Gutierrez-Micelli,Federico; Dendooven,Luc.
The semi-arid region of Chiapas is dominated by N2 -fixing shrubs, e.g., Acacia angustissima. Urea-fertilized soil samples under maize were collected from areas covered and uncovered by A. angustissima in different seasons and N2O and CO2 emissions were monitored. The objective of this study was to determine the effects of urea and of the rainy and dry season on gas emissions from semi-arid soil under laboratory conditions. Urea and soil use had no effect on CO2 production. Nitrons oxide emission from soil was three times higher in the dry than in the rainy season, while urea fertilization doubled emissions. Emissions were twice as high from soil sampled under A. angustissima canopy than from arable land, but 1.2 lower than from soil sampled outside the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Acacia angustissima; Denitrification; Nitrification; Soil water content; Urea.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832010000500015

Performance of pilot-scale vertical flow constructed wetlands with and without the emergent macrophyte Spartina alterniflora treating mariculture effluent
Provedor de dados: 52
Autores: Sousa,Wilson Treger Zydowicz; Panitz,Clarice Maria Neves; Thomaz,Sidinei Magela.
Vertical flow constructed wetlands, planted with and without Spartina alterniflora, were tested for the treatment of mariculture wastewater. Wetlands with and without the emergent macrophyte produced reductions of 89 and 71% for inorganic solids, 82 and 96% for organic solids, 51 and 63% for total nitrogen, 82 and 92% for ammoniacal nitrogen, 64 and 59% for orthophosphate, and 81 and 89% for turbidity, respectively. Wetlands with S. alterniflora showed denitrification tendencies, while wetlands without S. alterniflora had higher oxygen levels leading to nitrification. The results suggest the fundamental role of oxygen controlling the purification processes as well as the potential of constructed wetlands to treat mariculture effluents.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Artificial wetlands; Dissolved oxygen; Nitrification; Denitrification; Pollutant removal; Mariculture effluent.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132011000200024

The potential of denitrification for the stabilization of activated sludge processes affected by low alkalinity problems
Provedor de dados: 52
Autores: Hoffmann,Heike; Costa,Tatiana Barbosa da; Wolff,Delmira Beatriz; Platzer,Christoph; Costa,Rejane Helena Ribeiro da.
In this study, the problems provoked by nitrification of wastewater with low alkalinity were analyzed in a pilot sequencing batch activated sludge reactor (SBR). Decrease in pH resulted in disappearence of protozoa. De-flocculation of the activated sludge floc started below pH 6.5, resulting in enhanced effluent turbidity and loss of bacteria. Nitrification efficiency was affected below pH 6.2. The denitrification activity was not sufficient to keep up the pH, due to a low C/N ratio of the wastewater. Based on alkalinity and ammonia concentration of the wastewater and the necessary denitrification rate to prevent operational problems, was developed a prognostic diagram. The applicability of this diagram was tested for the SBR with excellent results. The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Alkalinity; Activated sludge; Nitrification; Denitrification.
Ano: 2007
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132007000200018

Denitrification coupled with methane anoxic oxidation and microbial community involved identification
Provedor de dados: 52
Autores: Cuba,Renata Medici Frayne; Duarte,Iolanda Cristina; Saavedra,Nora Katia; Varesche,Maria Bernadete Amâncio; Foresti,Eugenio.
In this work, the biological denitrification associated with anoxic oxidation of methane and the microbial diversity involved were studied. Kinetic tests for nitrate (NO3-) and nitrite (NO2-) removal and methane uptake were carried out in 100 mL batch reactors incubated in a shaker (40 rpm) at 30 ºC. Denitrificant/methanotrophic biomass was taken from a laboratory scale reactor fed with synthetic nitrified substrates (40 mgN L-1 of NO3- and subsequently NO2-) and methane as carbon source. Results obtained from nitrate removal followed a first order reaction, presenting a kinetic apparent constant (kNO3)) of 0.0577±0.0057d-1. Two notable points of the denitrification rate (0.12gNO3--N g-1 AVS d-1 and 0.07gNO3--N g-1 AVS d-1) were observed in the beginning...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Denitrification; Methylomonas sp; Methane oxidation.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132011000100022

Estimate of denitrifying microbiota in tertiary sewage treatment and kinetics of the denitrification process using different sources of carbon
Provedor de dados: 58
Autores: Marchetto,Margarida; Gianotti,Eloisa Pozzi; Campos,José Roberto; Pires,Roberto Cleto; Moraes,Elizabeth de Mattos.
A study of the kinetics of denitrification was carried out in the laboratory based on the quantification of N2O, the final product of the activity of denitrifying microorganisms, when the enzymatic reduction of N2O to N2 was blocked by acetylene. Concentrated mixed liquor (sludge from a reactor with intermittent aeration used for sewage treatment) was used as the inoculum, while methanol, acetic acid, glucose, effluent sewage from an anaerobic fluidized bed reactor and synthetic substrate simulating domestic sewage were used as carbon sources. The mean concentration of nitrate was 20 mg/L. Maxima of N2O production and NO3- consumption occurred between 0.5h and 2.0h of incubation using all the carbon sources, which characterized the denitrification process....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Denitrifying activity; Denitrifying bacteria; Denitrification; Tertiary treatment of domestic sewage.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822003000200003

Bacterial diversity in relatively pristine and anthropogenically-influenced mangrove ecosystems (Goa, India)
Provedor de dados: 58
Autores: Fernandes,Sheryl Oliveira; Kirchman,David L.; Michotey,Valérie D.; Bonin,Patricia C.; LokaBharathi,P.A.
To appreciate differences in benthic bacterial community composition at the relatively pristine Tuvem and the anthropogenically-influenced Divar mangrove ecosystems in Goa, India, parallel tag sequencing of the V6 region of 16S rDNA was carried out. We hypothesize that availability of extraneously-derived anthropogenic substrates could act as a stimulatant but not a deterrent to promote higher bacterial diversity at Divar. Our observations revealed that the phylum Proteobacteria was dominant at both locations comprising 43-46% of total tags. The Tuvem ecosystem was characterized by an abundance of members belonging to the class Deltaproteobacteria (21%), ~ 2100 phylotypes and 1561 operational taxonomic units (OTUs) sharing &amp;gt; 97% similarity. At...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bacteria; Denitrification; Diversity; Mangroves; Sediments.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000400006

Draft genome sequence of Vitellibacter aquimaris D-24T isolated from seawater
Provedor de dados: 58
Autores: Thevarajoo,Suganthi; Selvaratnam,Chitra; Chan,Kok-Gan; Goh,Kian Mau; Chong,Chun Shiong.
ABSTRACT Vitellibacter aquimaris D-24T (=KCTC 42708T = DSM 101732T), a halophilic marine bacterium, was isolated from seawater collected from Desaru beach, Malaysia. Here, we present the draft genome sequence of D-24T with a genome size of approximately 3.1 Mbp and G + C content of 39.93%. The genome of D-24T contains genes involved in reducing a potent greenhouse gas (N2O) in the environment and the degradation of proteinaceous compounds. Genome availability will provide insights into potential biotechnological and environmental applications of this bacterium.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Vitellibacter aquimaris; Genome sequence; Denitrification; Proteases.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822018000100010

Greenhouse Gas (CO2 AND N2O) Emissions from Soils: A Review
Provedor de dados: 117
Autores: Muñoz,Cristina; Paulino,Leandro; Monreal,Carlos; Zagal,Erick.
In agricultural activities, the main greenhouse gases (GHG) are those related to C and N global cycles. The impact of agriculture on GHG emissions has become a key issue, especially when considering that natural C and N cycles are influenced by agricultural development. This review focuses on CO2 and N2O soil emissions in terrestrial ecosystems, with emphasis in Chilean and similar agro-ecosystems around the world. The influence of land use and crop management practices on CO2 and N2O emissions is analyzed; some mitigation measures to reduce such emissions are also discussed here. More knowledge on the biological processes that promote of GHG emissions from soil will allow creating opportunities for agricultural development under friendly-environmental...
Tipo: Journal article
Palavras-chave: Global warming; Carbon dioxide; Nitrous oxide; Soil biological processes; Soil organic carbon; Nitrification; Denitrification.
Ano: 2010
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392010000300016