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Ammonia nitrogen desorption from sanitary landfill leachate in filling towers REA
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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Copper adsorption in tropical oxisols BABT
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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Copper desorption in a soil with variable charge Scientia Agricola
Casagrande,José Carlos; Jordão,Camila Beig; Alleoni,Luís Reynaldo Ferracciú; Camargo,Otávio Antônio de.
Adsorption processes of heavy metals in soils have been more extensively studied than desorption, in spite of this latter process being related to nutrient bioavailability in the soil solution. Copper desorption from surface (0-0.2 m) and subsurface (1.0 - 1.2 m) samples of an Anionic Acrudox was studied at two pH values (4.5 and 7.5). Soil samples were incubated with Cu rates varying from 0 to 400 mg kg-1, during 4 and 12 weeks, in the presence of CaCl2 as support electrolyte at concentrations of 0.01 and 0.001 mol L-1. Complete soil adsorption of added Cu was observed at pH 7.5 in all incubation periods, indicating that a 24h-shaking period was enough to reach equilibrium and maximum adsorption. Copper adsorption varied with the incubation period and was...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Copper; Desorption; Ionic strength; PH.
Ano: 2004 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162004000200012
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Effect of spray volume on the moisture of stored corn and wheat grains BABT
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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Environmental fate of chlordecone in coastal habitats: recent studies conducted in Guadeloupe and Martinique (Lesser Antilles) ArchiMer
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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Functionalized Charcoal as a Buffering Matrix of Copper and Zinc Availability Rev. Bras. Ciênc. Solo
Guimarães,Gelton Geraldo Fernandes; Giroto,Amanda Soares; Teixeira,Breno Cardoso; Vergütz,Leonardus; Cantarutti,Reinaldo Bertola.
ABSTRACT: High copper (Cu) and zinc (Zn) contents in soil can cause phytotoxicity to plants and contaminate surface and groundwater, with negative effects on agriculture and the environment. Functionalized charcoal (OCh) has high cation exchange capacity (CEC) and the ability to adsorb Cu and Zn and control their availability in the soil and water. An adsorption study at two pH levels was carried out to evaluate increasing Cu and Zn sorption capacity provided by the functionalization process of a charcoal. In addition, a kinetics study of competitive and non-competitive adsorption-desorption of Cu and Zn in OCh was also evaluated. The results showed that functionalized charcoal (Ch) increased CEC 8.7 times due to an increase in carboxyl and phenolic...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Adsorption; Desorption; Metals; Remediation; Biochar.
Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832018000100530
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Humic Substances and their Relation to Pesticide Sorption in Eight Volcanic Soils Planta Daninha
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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Imazaquin sorption in surface and subsurface soil samples PAB
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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La contamination de la Gironde par le cadmium : origine, extension, importance ArchiMer
Boutier, Bernard; Chiffoleau, Jean-francois; Jouanneau, Jean-marie; Latouche, Claude; Philipps, Isabelle.
In 1979, the French monitoring program RNO (Réseau National d'Observation de la qualité du milieu Marin) pointed out a dramatic cadmium contamination in the oysters from the Gironde estuary (up to 100 ug -1, dry weight). The wild oyster-beds upstream the estuary were shown to be the most contaminated. This result tends to point to the river as the source of the cadmium contamination. At the same rime, uncontaminated oysters from Arcachon were transplanted in the Gironde estuary (La Fosse, Dau). This ex periment confirmed the importance and proved the permanence of the contamination. Very high concentrations of dissolved cadmium (400 ng. 1-1) were measured in the estuarine mixing zone. This phenomenon can be explained by the desorption of cadmiumfrom...
Tipo: Text Palavras-chave: Cadmium; Désorption; Estuaire; Bilan géochimique; Contamination des huîtres; Cadmium; Desorption; Estuary; Geochemical budget; Oyster contamination.
Ano: 1989 URL: http://archimer.ifremer.fr/doc/00167/27820/26013.pdf
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MATHEMATICAL MODELING AND HYSTERESIS OF SORPTION ISOTHERMS FOR PADDY RICE GRAINS REA
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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MOBILITY AND BIOAVAILABILITY OF HEAVY METALS AND METALLOIDS IN SOIL ENVIRONMENTS J. Soil Sci. Plant Nutr.
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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Recovery of copper (II) absorbed in biomass of Cladosporium cladosporioides Scientia Agricola
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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Recovery of lead and cadmium ions from metal-loaded biomass of wild cocoyam (Caladium bicolor) using acidic, basic and neutral eluent solutions Electron. J. Biotechnol.
Horsfall Jnr,Michael; Ogban,Fred E.; Akporhonor,Eyetemi E..
The effects of acidic, basic and neutral reagents on the recovery of Pb2+ and Cd2+ from metal-loaded biomass of wild cocoyam (C. bicolor) were investigated by eluting the biomass in five successive cycles using 0.01 M HCl, 0.1 M HCl, 0.01 M NaOH, 0.1 M NaOH and distilled water at different contact times. The data showed that the ease of metal ion recovery from metal -loaded biomass by the eluent solutions is of the order 0.01 M HCl > 0.1 M HCl > 0.01 M NaOH > 0.1 M NaOH > distilled water. Over 94% Pb2+ and 74% Cd2+ of the initially adsorbed metals were recovered by 0.01 M HCl, while < 20% of both metals was recovered by basic reagent. Distilled water recovered less than 9% of both metal ions from the biomass. Macroscopic changes were also...
Tipo: Journal article Palavras-chave: Cocoyam; Desorption; Heavy metals removal; Metal recovery; Water treatment.
Ano: 2006 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-34582006000200009
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SORPTION ISOTHERMS AND ISOSTERIC HEAT OF PERICARP AND ENDOSPERM TISSUES OF ARABICA COFFEE FRUIT REA
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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Water sorption kinetics of damaged beans: GAB model AGRIAMBI
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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