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Registros recuperados: 22 | |
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FLÓREZ-ZAPATA,NATHALIA; GARCÍA,JUAN CARLOS; DEL PORTILLO,PATRICIA; RESTREPO,SILVIA; URIBE-VELEZ,DANIEL. |
In the S. tuberosum group phureja crops, mineral fertilizer and organic amendments are applied to meet the plants´ nutritional demands, however the effect of such practices on the associated rizospheric microbial communities are still unknown. Nitrogen plays an important role in agricultural production, and a great diversity of microorganisms regulates its transformation in the soil, affecting its availability for the plant. The aim of this study was to assess the structure of microbial communities related with the N cycle of S. tuberosum group phureja rizospheric soil samples, with contrasting physical-chemical properties and fertilization strategy. Few significant differences between the community composition at the phylum level were found, only... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Nitrogen cycle; Nitrification; Nitrogenase; Pyrosequencing; Solanum phureja. |
Ano: 2013 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-548X2013000300004 |
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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 |
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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 |
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DECKER,KELLY L.M; BOERNER,R.E.J. |
We measured net nitrogen mineralization, net nitrification, proportional nitrification, and total inorganic nitrogen, available phosphorus, and soil organic carbon in five Andean forested stands in an attempt to resolve the relative influence of elevation and forest canopy composition on soil organic matter and nutrient dynamics in this ecosystem type. Our five forested study sites were within a contiguous Nothofagus forest that ranged from 1,280 to 1,700 m elevation in the central Chilean Andes. The five sites consisted of three single species stands, one each of the low elevation deciduous N. obliqua, the evergreen N. dombeyi, or the high elevation deciduous N. pumilio, as well as two mixed evergreen-deciduous stands. There was no statistically... |
Tipo: Journal article |
Palavras-chave: Chilean Andes; Leaf lifespan; Nitrogen mineralization; Nitrification; Soil carbon. |
Ano: 2003 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2003000300003 |
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Mevel, Genevieve. |
Prawns (Panaeus japonicus) were rearing during more than nine months in experimental closed circuit tanks. In such systems the nitrite appearance is related to the normal nitrification process and to oxygen deficiency. Above a given level, nitrite causes the death of prawns. The soluble oxygen concentration and, thus, nitrite level in the water appears as the main factor for a successful development of prawns in closed circuit tanks. In these conditions, the growth rate of the prawns is relatively low (9g/per individual in seven months). Never theless, such a system allows a load of some 600 g prawns per m2. |
Tipo: Text |
Palavras-chave: Circuit clos; Nitrification; Peneide; Closed circuit; Nitrification; Peneide. |
Ano: 1979 |
URL: http://archimer.ifremer.fr/doc/00305/41655/40864.pdf |
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Morita, R; Jones, R. |
The nitrifying bacteria were found to survive 24 weeks in the absence of ammonium without decreasing their number of cell size. Because H sub(2), CO, and CH sub(4) are present in the marine environment, these substrates were investigated as a possible source of the energy of maintenance for the nitrifying bacteria. super(14)CO and super(14)CH sub(4) were found to be oxidized by the nitrifiers. N-serve was found to inhibit the oxidation of CO. Using the nitrifiers' ability to oxide CO, a method for the determination of the nitrification rate was developed. The ability of nitrifiers to oxidize CO may play a significant role in the cycling of CO sub(2) in the marine environment. Whether CO and CH sub(4) oxidation play a role in the survival of nitrifiers in... |
Tipo: Text |
Palavras-chave: Methane; Carbon dioxide; Survival; Bacteria; Nitrification; Nitrogen cycle; Oxidation; Carbon cycle; Biogeochemistry; Metabolism. |
Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-975.pdf |
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PARRON, L. M.; BUSTAMANTE, M. M. da C.; PRADO, C. L. C.. |
RESUMO: A disponibilidade de nitrogênio (N) inorgânico para as plantas, geralmente, depende da taxa de mineralização da matéria orgânica. A biomassa microbiana, além de indicadora da qualidade do solo, está relacionada à disponibilização de nutrientes. Este trabalho objetivou determinar as taxas de mineralização líquida de N e o carbono da biomassa microbiana (CBM) em solos, em um gradiente topográfico de Mata de Galeria no Distrito Federal, por 12 meses. O gradiente comporta três comunidades florísticas: úmida (margem do córrego), intermediária e seca (borda da mata), nas quais a produção líquida de N inorgânico foi 81,5; 29,2 e 25,3 kg N ha (elevado a -1) ano (elevado a -1), respectivamente. A quantidade de N-NO3- disponível na comunidade úmida foi 0,69... |
Tipo: Folhetos |
Palavras-chave: Microbial flora; Biomassa; Cerrado; Mineralização; Microbiologia do Solo; Nitrificação; Nitrogênio; População Microbiana; Solo; Umidade do Solo; Biomass; Nitrification; Mineralization; Nitrogen; Soil; Soil water content; Soil biology. |
Ano: 2003 |
URL: http://www.infoteca.cnptia.embrapa.br/infoteca/handle/doc/568114 |
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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 |
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Collos, Yves; Hadjadji, Imene; Plisson, Benoit; Cecchi, Philippe; Laabir, Mohamed; Bechemin, Christian; Masseret, Estelle. |
Alexandrium tamarense (M. Lebour) Balech strains isolated in spring 2007 from a single bloom in Thau lagoon have been grown in nonaxenic artificial media. For three strains showing large oscillations in biomass (crashes followed by recoveries) on a scale of several days, a significant relationship was observed between changes in cell densities (as in vivo fluorescence) and changes in nitrate concentrations. Increases in cell densities were accompanied by decreases in nitrate, while decreases in cell densities corresponded to increases in nitrate, presumably due to nitrification. Net increases in nitrate could reach up to 15 mu mol N . L(-1) . d(-1) indicating a very active nitrifying archaeal/bacterial population. However, following population crashes,... |
Tipo: Text |
Palavras-chave: Alexandrium tamarense; Archaea; Bacteria; Decay; Growth; Nitrate; Nitrification; Oscillations. |
Ano: 2011 |
URL: http://archimer.ifremer.fr/doc/00049/16046/13585.pdf |
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Tamires PETRY,Camila; Trindade COSTA,Daiane; DROSTE,Annette. |
ABSTRACT A promising method for the treatment of effluents is the use of floating macrophytes. Ammoniacal nitrogen is a typical compound present in urban landfill leachates and its removal is important due its toxicity to several organisms. Therefore, the study evaluated Typha domingensis survival and nitrification potential artificially floating in domestic solid waste leachate. Plants were exposed for 35 days to leachate (100, 75 and 50 %) and to rainwater with N:P:K (control). Dissolved oxygen (DO) of the treatments was periodically measured, and ammoniacal nitrogen, nitrite and nitrate were analyzed before and after exposure. At the end of the experiment, plant survival rate was calculated. After two weeks, DO increased twice in the control, three... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Cattail; Macrophyte; Nitrification; Phytoremediation. |
Ano: 2020 |
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-548X2020000100005 |
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Kölln,Oriel Tiago; Franco,Henrique Coutinho Junqueira; Ferreira,Danilo Alves; Vargas,Vitor Paulo; Castro,Saulo Augusto de Quassi; Cantarella,Heitor; Caldana,Camila; Trivelin,Paulo Cesar Ocheuze. |
ABSTRACT Retaining the mineral N in the form of NH4+ in the soil for a lengthy period is desirable for reducing losses. Furthermore, there is evidence that sugarcane prefers NH4+-N in place of NO3−-N. This study aimed firstly, to evaluate the potential of root extracts of Bracchiaria humidicola andSaccharum spontaneum, in contrast with the DCD (Dicyandiamide) inhibitor, to increase absorption of N by plants fertilized with ammonium sulfate, and secondly, to quantify the emission of N2O fluxes with the use of this inhibitor. The experiment was developed in a glasshouse in an entirely randomized design where four treatments were applied: AS) ammonium sulfate (control); AS+DCD) ammonium sulfate associated with dicyandiamide; AS+BCH) ammonium sulfate... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Ammonium; Nitrate; Dicyandiamide; Nitrification; Nitrous oxide. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162016000100034 |
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Castoldi,Gustavo; Reis,Jhônatas Gomes dos; Pivetta,Laércio Augusto; Rosolem,Ciro Antonio. |
Brachiaria species, particularly B. humidicola, can synthesize and release compounds from their roots that inhibit nitrification, which can lead to changes in soil nitrogen (N) dynamics, mainly in N-poor soils. This may be important in crop-livestock integration systems, where brachiarias are grown together with or in rotation with grain crops. The objective of the present study was to determine whether this holds true in N-rich environments and if other Brachiaria species have the same effect. The soil N dynamics were evaluated after the desiccation of the species B. brizantha, B. decumbens, B. humidicola, and B. ruziziensis, which are widely cultivated in Brazil. The plants were grown in pots with a dystroferric Red Latosol in a greenhouse. Sixty days... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Brachiaria brizantha; Brachiaria decumbens; Brachiaria humidicola; Brachiaria ruziziensis; Nitrification; Rhizosphere. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832013000600018 |
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Registros recuperados: 22 | |
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