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Registros recuperados: 15 | |
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Leite,Valderi D.; Barros,Aldre J. M.; Lopes,Wilton S.; Sousa,José T. de. |
Sanitary landfill leachates present high concentrations of carbonaceous and nitrogenous materials. The crucial point is that carbonaceous materials are of difficult biodegradation, what compromises the performance of biological treatment processes, while nitrogenous materials, such as ammonia nitrogen, probably preclude the use of biological treatments. Therefore, the aim of this work was to study the desorption process of ammonia nitrogen from sanitary landfill leachate in filling towers. Desorption was carried out in filling towers of 35 L capacity. The leachate was collected from a sanitary landfill located in João Pessoa, Paraíba State, Brazil. Desorption efficiency for the pH values adopted in four treatments was 93% minimum and 95.5% maximum, with... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Leachate; Ammonia nitrogen; Filling tower; Desorption. |
Ano: 2014 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162014000300017 |
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Dias,Camila de A.; Andrade,Ednilton T. de; Lemos,Isabella A.; Borém,Flávio M.; Barros,Ezequiel A.. |
ABSTRACT The aim of this study was to evaluate and model the hygroscopic equilibrium and isosteric heat curves of pericarp and endosperm tissues of arabica (Coffea arabica) coffee fruit, in different temperature and relative humidity conditions. Sorption isotherms were drawn under temperatures from 20°C to 70°C and relative humidity ranging between 10% and 90% until the product reached the equilibrium water content with the environment. The experiment was set up in a 4 × 4 factorial scheme (four relative humidity of the drying air and three tissues of the coffee cherry pericarp + endosperm [1: exocarp + part of the mesocarp, 2: mesocarp, 3: endocarp, 4: endosperm]), in a completely randomized design, with three repetitions. The results were examined by... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Adsorption; Coffea arabica; Desorption; Hygroscopic equilibrium; Mathematical modeling. |
Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000100078 |
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Zeymer,Juliana S.; Corrêa,Paulo C.; Oliveira,Gabriel H. H.; Baptestini,Fernanda M.; Campos,Renata C.. |
ABSTRACT Knowledge on sorption isotherms is important for predicting drying and storage processes of a product. A sorption isotherm can be generated from two processes: desorption and adsorption. The lag between these two curves is called hysteresis. Static method was used to obtain the equilibrium moisture content of paddy rice grains, in different temperature (10, 20, 30, 40 and 50 ± 1°C) and relative humidity (between 11 and 76% ± 2%) conditions. Equilibrium moisture content data were correlated with eight mathematical models and. The Chung Pfost model had the best fit to the experimental data. Desorption and adsorption isotherms, represented by the Chung Pfost model, showed a sigmoidal shape, characteristic of type II curve. Equilibrium moisture... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Adsorption; Desorption; Hygroscopic equilibrium; Relative humidity; Temperature. |
Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162019000400524 |
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Dromard, Charlotte R.; Devault, Damien; Bouchon-navaro, Yolande; Allénou, Jean-pierre; Budzinski, Hélène; Cordonnier, Sébastien; Tapie, Nathalie; Reynal, Lionel; Lemoine, Soazig; Thomé, Jean-pierre; Thouard, Emmanuel; Monti, Dominique; Bouchon, Claude. |
The organochlorine pollution by chlordecone, an insecticide spread in the past in banana plantations, is now recognized as a major ecological, economic, and social crisis in Guadeloupe and Martinique Islands. Due to its physical and chemical properties, this molecule is particularly persistent in the natural environment. Volcanic soil of Guadeloupe and Martinique contain allophanes (amorphous clays), which favor chlordecone trapping due to their structure and physical properties. Thus, with this trapping ability, allophanes serve as a vector allowing chlordecone to contaminate runoff waters and, finally, the sea. In the present publication, several studies recently conducted in the Lesser Antilles have been compiled in order to evaluate the desorption of... |
Tipo: Text |
Palavras-chave: Organochlorine pollution; Desorption; Allophane; Zooplankton; Trophic food webs; Bioamplification. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00484/59551/62539.pdf |
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Violante,A; Cozzolino,V; Perelomov,L; Caporale,A.G; Pigna,M. |
In soil environments, sorption/desorption reactions as well as chemical complexation with inorganic and organic ligands and redox reactions, both biotic and abiotic, are of great importance in controlling their bioavailability, leaching and toxicity. These reactions are affected by many factors such as pH, nature of the sorbents, presence and concentration of organic and inorganic ligands, including humic and fulvic acid, root exudates, microbial metabolites and nutrients. In this review, we highlight the impact of physical, chemical, and biological interfacial interactions on bioavailability and mobility of metals and metalloids in soil. Special attention is devoted to: i) the sorption/desorption processes of metals and metalloids on/from soil components... |
Tipo: Journal article |
Palavras-chave: Bioavailability; Heavy metals; Metalloid; Adsorption; Desorption; Chemical speciation. |
Ano: 2010 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-95162010000100005 |
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Oliveira,Maurílio Fernandes de; Prates,Hélio Teixeira; Santanna,Derli Prudente; Oliveira Júnior,Rubem Silvério de. |
The objective of this work was to study the sorption and desorption of imazaquin, in surface and subsurface soil samples from Brazil. Sorption and desorption steps were carried out using batch equilibration and high performance liquid chromatography analytical routines. The value of Kf,ads was positively correlated with clay content, and negatively correlated with pH of supernatant. Samples from Typic Haplustox, clayey soil profile having high clay content, provided higher Kf,ads values, and negative correlation with organic carbon, silt content, cation exchange capacity and pH. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Retention; Desorption; Oxisol; Sustainability. |
Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2006000300013 |
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ALISTER,C.; ARAYA,M.; CORDOVA,A.; SAAVEDRA,J.; KOGAN,M.. |
ABSTRACT: Pesticide soil sorption is a primary factor that influences the fate of pesticides in the environment, affecting regulation of microbiological and chemical degradation, volatilization and leaching. The main goal of this research was to study the effect of the organic phase of volcanic soils on sorption of agricultural pesticides. Sorption and desorption of eight agricultural pesticides were studied on eight volcanic soils that varied in the fulvic and humic constituents of their organic matter. For all pesticides, sorption was well described by a Freundlich isotherm where 1/nads values indicated that the sorption mechanism could be mainly explained by physical reactions in all soils. Kf values for carbaryl and flumioxazin were the highest with... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Adsorption; Desorption; Isotherms; Freundlich. |
Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582020000100221 |
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Baptestini,Fernanda M.; Corrêa,Paulo C.; Vanegas,Jaime D. B.; Leite,Rafael; Botelho,Fernando M.; Campos,Renata C.. |
ABSTRACT The objective of this study was to model the water sorption kinetics of damaged beans. Grains with initial moisture content of 53.85%, dry basis (d.b.), were used. One portion of the grains was used to obtain desorption isotherms, while the other was subjected to drying until the moisture content of 5.26% (d.b.), so that it was subjected to the adsorption. For the induction of damage, a Stein Breakage Tester was used. To obtain the equilibrium moisture content, grains were placed in a climatic chamber at 20, 30, 40 and 50 ± 1 °C combined with relative humidity of 30, 40, 50, 70 and 90 ± 3%. The GAB model fitted well to the equilibrium moisture experimental data of damaged grains and control. With increasing temperature, the monolayer moisture... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Hysteresis; Adsorption; Desorption; Phaseolus vulgaris L.. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662017000800550 |
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Carmo,Juliana Ribeiro do; Pimenta,Carlos José; Silva,Júlia Ferreira da; Souza,Sara Maria Chaulfoun de. |
The biosorption process, characterized by the use of biomass for removing metals from aqueous solutions, is an attractive technology using inactive and dead biomasses to remove heavy metals from aqueous solutions in the absence of metabolic activity necessary for intracellular accumulation. The desorption process, which concentrates the metal previously absorbed for possible reuse, is also important. The desorption of copper (Cu) (II) associated with the biomass of Cladosporium cladosporioides (Fres) de Vries was evaluated following the biosorption process (adsorption). Specifically, four eluents were used (all at a concentration 0.1 mol L-1), sulfuric acid, hydrochloric acid, ethylenediaminetetraacetate disodium and calcium chloride, as well as the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biosorption; Metal; Desorption. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162013000300002 |
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Vásquez-Castro,Javier Alberto; Baptista,Gilberto Casadei de; Gadanha Junior,Casimiro Dias; Trevizan,Luiz Roberto Pimentel. |
The goal of this work was to evaluate the effect of spray volume on the moisture of the stored grains of the corn and wheat. Two kg of each type of the grain were placed into the plastic bags and sprayed with the theoretical doses of 0, 1, 3, 5, 8, and 10 liters of water / ton of the grain. The grain moisture content was evaluated 24 h after the spray operation by the oven method. The increase in the grain moisture was quadratic and showed the same trend in both the corn and wheat. The grain moisture after spraying 10 L.t-1 showed little increase (0.8 %) as compared to the initial moisture content. Thus, the application of any spray volume as used in this study made no difference for a possible better uniformity in the distribution of insecticide... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Stored products; Chemical control; Application technology; Desorption; Hygroscopic equilibrium. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132008000300003 |
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Silveira,Maria Lucia Azevedo; Alleoni,Luís Reynaldo Ferracciú. |
Cu adsorption, at concentrations between 0 to 800 mg L-1, was evaluated in surface and subsurface samples of three Brazilian soils: a heavy clayey-textured Rhodic Hapludalf (RH), a heavy clayey-textured Anionic ''Rhodic'' Acrudox (RA) and a medium-textured Anionic ''Xanthic'' Acrudox (XA). After adsorption, two consecutive extractions were performed to the samples which received 100 mg L-1 copper. Surface samples adsorbed higher amounts of Cu than the subsurface, and exhibited lower Cu removed after the extractions, reinforcing the influence of the organic matter in the reactions. Cu adsorption was significant in the subsurface horizons of the Oxisols, despite the positive balance of charge, demonstrating the existence of mechanisms for specific... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Adsorption; Isotherms; Desorption; Tropical soil. |
Ano: 2003 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132003000400006 |
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Registros recuperados: 15 | |
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