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Comparison of adsorbent films obtained by plasma polymerization of oxygenated organic compounds

LIMA, R. R.; HEMANDEZ, L. F.; FACHINI, E.; DEMARQUETTE, N. R.; SILVA, M. L. P.
Fonte: ELSEVIER SCIENCE SA Publicador: ELSEVIER SCIENCE SA
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.00173%
Thin films obtained by plasma polymerization of ethyl ether, methyl or ethyl acetate, acetaldehyde, acetone and 2-propanol were compared. Infrared spectroscopy (FFIR), resistance to chemicals, contact angle measurements, X-ray photoelectron spectroscopy (XPS), optical and scanning electron microscopy (SEM), and quartz crystal microbalance (QCM) were carried out. For all films FTIR showed high intensity for polar bonds yet the films are not resistant to polar solvents. Contact angle measurements revealed hydrophilic and organophilic surfaces and XPS pointed out a high proportion of oxygenated bonds. All films showed good step coverage and peeling was significant only with acetone and 2-propanol. All films are adsorbent for organic compounds in a large scale of polarity but acetaldehyde and 2-propanol act like a selective membrane. Also, deposition of these films on hydrophobic substrates leads to island formation. A possible model to explain the results must consider the hydrogen bridge formation on 2-propanol and acetaldehyde films. Ethyl ether, ethyl and methyl acetate showed good characteristics for development of sensor and sample pretreatment using miniaturized devices. (C) 2007 Elsevier B.V. All rights reserved.

Corrosion resistant and adsorbent plasma polymerized thin film

LIMA, R. R.; HERNANDEZ, L. F.; CARVALHO, A. T.; CARVALHO, R. A. M.; SILVA, M. L. P. da
Fonte: ELSEVIER SCIENCE SA Publicador: ELSEVIER SCIENCE SA
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.00173%
Adsorbent and corrosion resistant films are useful for sensor development. Therefore, the aim of this work is the production and characterization of plasma polymerized fluorinated organic ether thin films for sensor development. The polymerized reactant was methyl nonafluoro(iso)butyl ether. Infrared Spectroscopy showed fluorinated species and eventually CO but CH(n) is a minor species. Contact angle measurements indicated that the film is hydrophobic and organophilic but oleophobic. Optical microscopy reveals not only a good adherence on metals and acrylic but also resistance for organic solvents, acid and basic aqueous solution exposure. Double layer and intermixing are possible and might lead to island formation. Quartz Crystal Microbalance showed that 2-propanol permeates the film but there is no sensitivity to n-hexane. The microreactor manufactured using a 73 cm long microchannel can retain approximately 9 X 10(-4) g/cm(2) of 2-propanol in vapor phase. Therefore, the film is a good candidate for preconcentration of volatile organic compounds even in corrosive environment. (C) 2009 Elsevier B.V. All rights reserved.

Adsorbent new materials and composites produced in a single step

LIMA, R. R.; CARVALHO, R. A. M.; CARVALHO, A. T.; SIMOES, E. W.; SILVA, M. L. R. da
Fonte: ELSEVIER SCIENCE SA Publicador: ELSEVIER SCIENCE SA
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.260017%
The aim of this work is the production and preliminary characterization of adsorbent new materials useful for sensor development. A new plasma chamber was simulated and designed in order to obtain multiple layers and/or composites in a single step. Plasma deposited organic fluorocompound and hexamethyldisilazane (HMDS) thin films were produced and tested as adsorbent layers. Chemical characterization used ellipsometry, Raman. infrared and X-ray photoelectron spectroscopy. Hydrophobic and oleophobic character were determined by contact angle measurements. Adsorption characteristics were evaluated using quartz crystal microbalance. Not only HMDS but also the fluorocompound can polymerize but intermixing and a double layer are only obtained in very narrow conditions. The films are adsorbent and mildly hydrophobic. Films deposited on a microchromatographic column can be used on sample pretreatment to remove and/or preconcentrate volatile organic Compounds. Therefore, with this approach it is possible to obtain films with different monomers on double layer or composites, with organic/inorganic materials or particles and use them on sample pretreatment for chemical analysis. (C) 2008 Elsevier B.V. All rights reserved.; University of Puerto Rico; FAPESP; CNPq

"A utilização de turfa como adsorvente de metais pesados. O exemplo da contaminação da Bacia do Rio Ribeira de Iguape por chumbo e metais associados" ; "The utilization of peat as heavy metal adsorbent. The example of the contamination of Ribeira do Iguape River catchment by lead and associated minerals"

Franchi, José Guilherme
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 19/11/2004 PT
Relevância na Pesquisa
37.00173%
Este trabalho teve como objetivos principais a caracterização da mina de turfa de Eugênio de Melo, localizada no Estado de São Paulo, região do Vale do Rio Paraíba do Sul, bem como uma amostra representativa do seu minério. Esta amostra foi testada sob duas condições – in natura e tratada com ácido clorídrico – como adsorvente de metais pesados visando a aplicação do minério em processos de tratamento de efluentes líquidos. Adotaram-se como estudos de caso lixívias obtidas a partir de resíduos da mineração de sulfetos de chumbo e metais associados existentes na região do alto curso do Rio Ribeira de Iguape, geradas em laboratório. Tais depósitos encontram-se sob a forma de extensos corpos às margens de importantes drenagens, circunscritas à região de Adrianópolis (PR). A possibilidade de liberação dos metais pesados presentes nestes depósitos para o ambiente foi avaliada através de estudos granulométricos, mineralógicos e químicos de uma coluna amostrada num destes depósitos. Os teores dos metais presentes nas lixívias enquadraram-nas como não passíveis de descarte para o ambiente sem tratamento prévio, segundo a legislação estadual e federal que regem o assunto. Os resíduos da mineração aqui estudados...

Determinação de produtos de biotransformação de aflotoxina B1 e aplicabilidade na avaliação da eficiência de um adsorvente à base de aluminossilicato de cálcio e sódio hidratado em frangos de corte; Determination of aflatoxin B1 biotransformation products and applicability for the efficacy evaluation of a hydrated sodium calcium aluminosilicate-based adsorbent in broiler chicks

Neeff, Diane Valganon de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 28/06/2012 PT
Relevância na Pesquisa
37.260017%
O objetivo do presente trabalho foi determinar resíduos de aflatoxinas M1 (AFM1), aflatoxicol (AFL), B1 (AFB1), B2 (AFB2), G1 (AFG1) e G2 (AFG2) não metabolizadas no fígado e rim de frangos de corte, com a finalidade de verificar sua aplicabilidade na avaliação da eficiência de um adsorvente comercial à base de aluminossilicato de cálcio e sódio (HSCAS) incorporado na dieta, bem como determinar o percentual de ligação do adsorvente com a AFB1em ensaios in vitro. Cem frangos de corte (Ross 708), machos, de 1 dia de idade, foram mantidos em baterias metálicas, com acesso ad libitum à ração e água. Utilizou-se um delineamento inteiramente casualizado com 4 tratamentos, sendo cada tratamento composto por 5 gaiolas contendo 5 frangos em cada uma. Os tratamentos foram os seguintes: A) dieta basal (DB), sem adição de HSCAS ou AFB1; B) DB com adição de 0,5% de HSCAS; C) DB com adição de 2,5 mg/kg de AFB1; e D) DB com adição de 2,5 mg/kg de AFB1 e 0,5% de HSCAS. As rações experimentais foram administradas de 1 a 21 dias de vida. No dia 21, 5 frangos de cada tratamento foram insensibilizados com dióxido de carbono, mortos por deslocamento cervical e amostras de fígado e rim foram coletadas para análise de resíduos de AFB1. O HSCAS foi efetivo em se ligar...

Performance and egg quality of laying hens fed diets containing aflatoxin, fumonisin and adsorbent

Siloto, EV; Sartori, DRS; Oliveira, EFA; Sartori, JR; Fascina, VB; Berto, da
Fonte: Fundação APINCO de Ciência e Tecnologia Avícolas Publicador: Fundação APINCO de Ciência e Tecnologia Avícolas
Tipo: Artigo de Revista Científica Formato: 21-28
ENG
Relevância na Pesquisa
37.39231%
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); The effects of aflatoxin and fumonisin and their combination on egg production and quality, as well as the efficacy of a mycotoxin adsorbent in reducing or eliminating these effects in commercial layers. A number of 168 layers with initial age of 37 weeks were submitted to an experimental period of 56 days. A completely randomized experimental design in a 3x2+1 factorial arrangement was applied (3 treatments with mycotoxins: aflatoxin (AF), fumonisin (FU), or aflatoxin + fumonisin (AF+FU); 2 treatments with or without adsorbent; and a control group that was fed no mycotoxins, nor adsorbent), totaling 7 treatments with 6 replicated of 4 birds/cage. The dietary inclusion levels were 1ppm AF, 25ppm FU, and 2 kg adsorbent/ton feed. Birds fed AF presented the lowest percentage of lay (p=0.0594). Egg mass was the lowest (p<0.05) in the AF+FU treatment (49.49g). The treatment with AF resulted in higher eggshell thickness and strength (p<0.05) than the FU treatment and the control group. The inclusion of the adsorbent in the AF contaminated feed reduced eggshell strength, which returned to levels similar to those of the control group. The observed changes indicate that aflatoxin is toxic at a concentration of 1ppm...

The reactive surface of Castor leaf [Ricinus communis L.] powder as a green adsorbent for the removal of heavy metals from natural river water

Martins, Amanda E.; Pereira, Milene S.; Jorgetto, Alexandre O.; Martines, Marco A.U.; Silva, Rafael I.V.; Saeki, Margarida J.; Castro, Gustavo R.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 24-30
ENG
Relevância na Pesquisa
37.00173%
In this study, a green adsorbent was successfully applied to remove toxic metals from aqueous solutions. Dried minced castor leaves were fractionated into 63-μm particles to perform characterization and extraction experiments. Absorption bands in FTIR (Fourier Transform Infrared Spectroscopy) spectra at 1544, 1232 and 1350 cm-1 were assigned to nitrogen-containing groups. Elemental analysis showed high nitrogen and sulfur content: 5.76 and 1.93%, respectively. The adsorption kinetics for Cd(II) and Pb(II) followed a pseudo-second-order model, and no difference between the experimental and calculated Nf values (0.094 and 0.05 mmol g-1 for Cd(II) and Pb(II), respectively) was observed. The Ns values calculated using the modified Langmuir equation, 0.340 and 0.327 mmol g-1 for Cd(II) and Pb(II), respectively, were superior to the results obtained for several materials in the literature. The method proposed in this study was applied to pre-concentrate (45-fold enrichment factor) and used to measure Cd(II) and Pb(II) in freshwater samples from the Paraná River. The method was validated through a comparative analysis with a standard reference material (1643e). © 2013 Elsevier B.V. © 2013 Elsevier B.V. All rights reserved.

Design of an adsorbent employing activated carbon fiber to remove lead

Cárdenas-López,C.; Camargo,G.; Giraldo,L.; Moreno-Piraján,J.C.
Fonte: Fundação Editora da Universidade Estadual Paulista Júlio de Mesquita Filho - UNESP Publicador: Fundação Editora da Universidade Estadual Paulista Júlio de Mesquita Filho - UNESP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2007 EN
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Zorflex® activated carbon fibers (ACF), reference FM100 198B, are used before and after an oxidizing procedure with H3PO4 to study the adsorption of Pb2+. The point of zero charge was determined for the modified and unmodified fiber giving values of 2.3 and 4.3, respectively. After oxidizing the ACF, the fiber showed to have a greater Pb2+ adsorption capacity in comparison with the unmodified fiber, which is related with the acid sites increase, where lead was mainly adsorbed. Determination of the BET area was carried out by nitrogen physisorption at 77K. ACFs presented superficial areas between 1000 and 1500 m²/g showing mostly, a microporous structure. The preliminary design of an adsorbent using the modified fiber is presented where the fiber superior physicochemical properties over the unmodified one are observed.

Study on preparation of a vovel silica adsorbent and its selective separation applied to genistein

Zhang,Yuqing; Zhang,Yahui; Zhang,Hongliu
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2008 EN
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37.260017%
In order to selectively separate genistein from its crude solution, a novel silica adsorbent was prepared using genistein as the template molecule, gamma-aminopropylthriethoxysilane as the functional monomer and tetraethyl orthosilicate as the cross-linker. It was analyzed by the BET, FTIR, TEM characteristics, the static adsorption experiment, and selective adsorption experiment. The results show that the silica adsorbent has high specific area, special selectivity and high adsorption capacity for genistein. It can recognize and bind genistein in aqueous solution, and lots of nanopores distribute on its surface uniformly. It is concluded that both the shape and size of the recognition sites matching the template molecule result in the performance of this adsorbent to bind genistein and that there are strong ionic and hydrogen bond attractions between the phenolic hydroxyl and the -NH2.

Deep removal of 4,6-dimethyldibenzothiophene from model transportation diesel fuels over reactive adsorbent

Wang,Shengqiang; Wang,Ruicong; Yu,Hongbing
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2012 EN
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37.335352%
This paper presents a new reactive adsorbent used to effectively remove 4,6-dimethyldibenzothiophene (4,6-DMDBT) from model transportation diesel fuels. This reactive adsorbent was composed of formaldehyde, phosphotungstic acid and mesoporous silica gel. The experiment was based on an assumed condensation reaction of 4,6-DMDBT with formaldehyde using phosphotungstic acid as catalyst in pore spaces. The effect of temperature and the amount of formaldehyde and phosphotungstic acid loaded on the substrate were investigated in a batch system. In the breakthrough experiment, three different model diesel fuels containing 1000 mg/kg 4,6-DMDBT were pumped through a fixed-bed reactor packed with reactive adsorbent at constant temperature and atmospheric pressure, respectively. The experimental results showed that sulfur-free model fuel was obtained at 80ºC despite the presence of aromatics. The sulfur capacity of regenerated reactive adsorbent was almost totally recovered.

Performance and egg quality of laying hens fed diets containing aflatoxin, fumonisin and adsorbent

Siloto,EV; Sartori,DRS; Oliveira,EFA; Sartori,JR; Fascina,VB; Berto,DA
Fonte: Fundação APINCO de Ciência e Tecnologia Avícolas Publicador: Fundação APINCO de Ciência e Tecnologia Avícolas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2011 EN
Relevância na Pesquisa
37.39231%
The effects of aflatoxin and fumonisin and their combination on egg production and quality, as well as the efficacy of a mycotoxin adsorbent in reducing or eliminating these effects in commercial layers. A number of 168 layers with initial age of 37 weeks were submitted to an experimental period of 56 days. A completely randomized experimental design in a 3x2+1 factorial arrangement was applied (3 treatments with mycotoxins: aflatoxin (AF), fumonisin (FU), or aflatoxin + fumonisin (AF+FU); 2 treatments with or without adsorbent; and a control group that was fed no mycotoxins, nor adsorbent), totaling 7 treatments with 6 replicated of 4 birds/cage. The dietary inclusion levels were 1ppm AF, 25ppm FU, and 2 kg adsorbent/ton feed. Birds fed AF presented the lowest percentage of lay (p=0.0594). Egg mass was the lowest (p<0.05) in the AF+FU treatment (49.49g). The treatment with AF resulted in higher eggshell thickness and strength (p<0.05) than the FU treatment and the control group. The inclusion of the adsorbent in the AF contaminated feed reduced eggshell strength, which returned to levels similar to those of the control group. The observed changes indicate that aflatoxin is toxic at a concentration of 1ppm, and that the effects of fumonisin were less evident as a function of the low dose applied. The inclusion of the glucan (2kg/ton) effectively reverted some of the toxic effects of aflatoxin and...

Endotoxin removal from water using microporous polyethylene chopped fibres as a new adsorbent.

Sawada, Y.; Fujii, R.; Igami, I.; Kawai, A.; Kamiki, T.; Niwa, M.
Fonte: Cambridge University Press Publicador: Cambridge University Press
Tipo: Artigo de Revista Científica
Publicado em /08/1986 EN
Relevância na Pesquisa
27.43689%
A new adsorbent, microporous polyethylene chopped fibre, was produced from a high density polyethylene. This can adsorb lipopolysaccharides (LPS) linearly up to 2 h, and showed the highest capacity to adsorb LPS when compared with two other polyethylene-based adsorbents and a polystyrene-based adsorbent. More than twice as much orange II and 4-nitroquinoline N oxide were adsorbed in the new adsorbent as was LPS. The adsorption isotherm of the new adsorbent for LPS was of Ln type, the correlation between adsorption and concentration of solute was proportional; whereas orange II and 4-nitroquinoline N oxide were of L type (greater adsorption than Ln type); tetrachloroethylene adsorption was of S type, less than Ln type. Adsorption of LPS to the new adsorbent increased when temperature rose, whereas adsorption of orange II and 4-nitroquinoline N oxide decreased. These data suggest that the binding of LPS to the new adsorbent is a hydrophobic interaction, whereas the binding of both orange II and 4-nitroquinoline N oxide is not. The new adsorbent has a greater potential for the removal of endotoxin from tap water than other commercially available adsorbents such as charcoal and Amberlite XAD-2.

Volumetric Interpretation of Protein Adsorption: Capacity Scaling with Adsorbate Molecular Weight and Adsorbent Surface Energy

; Parhi, Purnendu; Golas, Avantika; Barnthip, Naris; Noh, Hyeran; Vogler, Erwin A.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
27.547656%
Silanized-glass-particle adsorbent capacities are extracted from adsorption isotherms of human serum albumin (HSA, 66 kDa), immunoglobulin G (IgG, 160 kDa), fibrinogen (Fib, 341 kDa), and immunoglobulin M (IgM, 1000 kDa) for adsorbent surface energies sampling the observable range of water wettability. Adsorbent capacity expressed as either mass-or-moles per-unit-adsorbent-area increases with protein molecular weight (MW) in a manner that is quantitatively inconsistent with the idea that proteins adsorb as a monolayer at the solution-material interface in any physically-realizable configuration or state of denaturation. Capacity decreases monotonically with increasing adsorbent hydrophilicity to the limit-of-detection (LOD) near τo = 30 dyne/cm (θ~65o) for all protein/surface combinations studied (where τo≡γlvocosθ is the water adhesion tension, γlvo is the interfacial tension of pure-buffer solution, and θ is the buffer advancing contact angle). Experimental evidence thus shows that adsorbent capacity depends on both adsorbent surface energy and adsorbate size. Comparison of theory to experiment implies that proteins do not adsorb onto a two-dimensional (2D) interfacial plane as frequently depicted in the literature but rather partition from solution into a three-dimensional (3D) interphase region that separates the physical surface from bulk solution. This interphase has a finite volume related to the dimensions of hydrated protein in the adsorbed state (defining “layer” thickness). The interphase can be comprised of a number of adsorbed-protein layers depending on the solution concentration in which adsorbent is immersed...

Adsorvente a base de glucomanano em dietas de frangos de corte alimentados com milho contaminado.; Adsorbent based on glucomannan in diets of broilers fed mouldy corn.

LOPES, Lorena Lacava
Fonte: Universidade Federal de Pelotas; Zootecnia; Programa de P??s-Gradua????o em Zootecnia; UFPel; BR Publicador: Universidade Federal de Pelotas; Zootecnia; Programa de P??s-Gradua????o em Zootecnia; UFPel; BR
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
37.472725%
This study aimed to investigate the use of sterified glucomannan adsorbent on the productive performance of broilers of broilers fed mouldy corn.. A total of 1440 dayold broilers were allocated in pens, ten replications per treatment. Treatments were: T1 non-mouldy corn, without adsorbent (control); T2- non-mouldy corn with adsorbent; T3- mouldy corn without adsorbent and T4- mouldy corn with adsorbent. Weekly, birds and diets were evaluated for weight gain, feed intake, feed conversion, viability and efficiency factor. No significant interaction between corn and adsorbent was observed. Mouldy corn brought about a decrease in feed consumption, feed efficiency and viability. However, birds fed mycotoxin adsorbent showed better feed efficiency, viability and efficiency factor. These results indicate that the use of mouldy corn in broilers diets has negative effects on performance and the addition of absorbent improves feed conversion, efficiency factor and viability of the birds.; Objetivou-se avaliar os efeitos de um adsorvente ?? base de glucomanano esterificado, em dietas contendo milho naturalmente fungado para frangos de corte, sobre o desempenho zoot??cnico. O estudo foi realizado durante 42 dias experimentais, utilizando-se 1440 frangos de corte com um dia de idade. Os animais foram submetidos a quatro tratamentos...

Efeito das aflatoxinas e dos adsorventes sobre o desempenho zoot??cnico de alevinos e juvenis de jundi?? (Rhamdia quelen).; Aflatoxin and adsorbent effects on jundi?? fingerlings and juveniles performance

LOPES, Paulo Rodinei Soares
Fonte: Universidade Federal de Pelotas; Zootecnia; Programa de P??s-Gradua????o em Zootecnia; UFPel; BR Publicador: Universidade Federal de Pelotas; Zootecnia; Programa de P??s-Gradua????o em Zootecnia; UFPel; BR
Tipo: Tese de Doutorado Formato: application/pdf
POR
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37.155708%
Three experiments were carried out at the Ictyology Laboratory (Departamento de Zootecnia UFPel) to evaluate: a) - aflatoxin effects and b) - adsorptive action of 2 adsorbents (sodium and calcium aluminum-silicate and glucomanane) on growth and hematologic paramaters of jundi?? (Rhamdia quelen) fingerlings, fed diets artificially contaminated. The first experiment consisted of 360 fingerlings (initial weight 4 g), raised during 90 days in thermo-regulated recirculation water system. Twelve treatments were compared, with 3 replications. Four levels of aflatoxin inclusion in diets (0, 150, 250 e 350 μgAFkg-1), with and without (0, 0.3 and 0,6%) adsorbent addition (sodium and calcium aluminum-silicate). Negative effect of aflatoxins significantly reduced (P<0.05) growth and weight gain of fingerlings, proportionately to increasing levels of aflatoxis in diet, without mortality occurrence. Adsorbent levels in diet did not diminish the effect of aflatoxins on fish performance. The second experiment evaluated the effect of aflatoxins and 2 adsorbents (sodium and calcium aluminum-silicate) on performance of 189 jundi?? juveniles (initial weight 43.13 g),grown during 60 days. Nine treatments with 3 replications, 3 levels of aflatoxin inclusion in diet (0...

Comparison of Adsorbent with Varying Spacer Arm Length and Ligand Density for the Purification of Recombinant Hepatitis B Virus Surface Antigen

Li, R.H.; Li, Y.; Bi, J.; Zhao, L.; Zhou, W.; Huang, Y.; Zhang, Y.; Sun, L.J.; Wang, H.J.; Su, Z.
Fonte: Allerton Press, Inc. Publicador: Allerton Press, Inc.
Tipo: Artigo de Revista Científica
Publicado em //2007 EN
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37.00173%
Novel hydrophobic adsorbents were synthesized by immobilizing butyl derivative onto the highly cross-linked agarose beads manufactured in China, which are used as matrix. The effects of the spacer arm length (3C, 8C, and 10C) and ligand density (from 13 to 45 μmol/mL) on the hydrophobicity were investigated using purified Hepatitis B surface antigen (HBsAg) expressed by CHO cell lines. Also, considering the effects of salt concentration and pH on HBsAg recovery and purification factor, orthogonal experiment design method was used to evaluate the adsorbents. The results showed the butyl-S adsorbent with the spacer arm length of 8C and the ligand density of 22 μmol/mL gel showed the best performance for the separation of HBsAg. Approximately 100% HBsAg recovery and 60 as purification fold were achieved by this media under the operating conditions of pH 7.0 and 9% salt concentration.; http://www.sciencedirect.com/science/journal/18722075; Copyright © 2007 Institute of Microbiology, Chinese Academy of Sciences and Chinese Society for Microbiology

A novel color removal adsorbent from heterocoagulation of cationic and anionic clays

Hu, Q.; Xu, Z.; Qiao, S.; Haghseresht, F.; Wilson, M.; Lu, G.
Fonte: Academic Press Inc Elsevier Science Publicador: Academic Press Inc Elsevier Science
Tipo: Artigo de Revista Científica
Publicado em //2007 EN
Relevância na Pesquisa
37.260017%
We report the preparation and characterization of a novel nanocomposite adsorbent for anionic dye removal. The nanocomposite adsorbent was prepared by heterocoagulation of delaminated bentonite and layered double hydroxide (LDH) colloids. The effects of preparation conditions, LDH loading, particle size, and calcination temperature of the modified material on the physicochemical properties of this composite adsorbent have been investigated. The optimal conditions for best Reactive Yellow 2 (RY2) dye removal efficiency are a weight ratio of LDH to bentonite of 1:1, LDH particle size 100 nm, and calcination temperature 673 K. The adsorption equilibrium data can be fitted well by the widely accepted adsorption isotherm models.; Qiuhong Hu, Zhiping Xu, Shizhang Qiao, Fouad Haghseresht, Michael Wilson, Gao Qing Lu

Obtenção de filme adsorvente de celulose/SBA-15 para limpeza de superfícies policromadas em obras de arte; Achievement of cellulose/SBA-15 adsorbent film for cleaning polychrome surfaces in works of art

Rizzo, Marcia de Mathias
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 11/06/2015 PT
Relevância na Pesquisa
37.155708%
O verniz acrílico Paraloid B72TM é um termoplástico que atua como um bom adesivo formando filmes claros. Tem sido usado em conservação e restauração de bens culturais desde os anos 50. Por apresentar Tg próximo a 40°C, no Brasil, algumas substâncias podem ficar adsorvidas à superfície de camadas pictóricas envernizadas. Nesse caso, a limpeza tradicional (palito com algodão e solventes) pode acarretar danos (penetração do solvente, abrasão, etc.) à obra de arte. A limpeza por métodos aquosos (géis e emulsões) pode deixar resíduos que interagem com os materiais originais. Por outro lado, a utilização de nano-géis magnéticos é bastante restrita e de difícil acesso. Esse trabalho tem por objetivo o desenvolvimento de filmes adsorventes de celulose/SBA-15 para retirada do verniz Paraloid B72TM, onde se fizer necessário. Esses filmes foram empregados sobre miméticos (pinturas originais de diferentes técnicas e obras confeccionadas para estudo envernizadas com Paraloid B72TM) para verificação de sua eficácia. As matérias primas, os miméticos e os filmes adsorventes, antes e após a aplicação, foram caracterizadas por técnicas físico-química e analíticas [análise térmica (TG/DTG e DTA); espectroscopia no infravermelho (FTIR); microscopia eletrônica de varredura (MEV); microscopia eletrônica de transmissão (MET); espectroscopia de fluorescência de raios X (XRF)...

Development of cerium dioxide coated alumina adsorbent to study the removal of arsenic from ground water

Herder, Laura
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
37.335352%
Arsenic contamination of groundwater is a major problem in both developing and developed countries as it is quite dangerous at extremely low concentrations and prevalent in many water supplies. Although there are many removal techniques for arsenic, the most promising for developing countries appears to be adsorption, since it is relatively low in cost, is easy to implement, requires no electricity, and can remove trace amounts of materials from solutions. Current adsorbents that have a high affinity for arsenic, but are costly because they have slow adsorption rates, low capacities, limited pH ranges, are affected adversely by competing ions, and often cannot be regenerated. One of the most successful adsorbent materials for arsenic removal is cerium dioxide, but unfortunately, this compound is quite expensive because of its rare earth component, cerium. Previous studies have utilized pure cerium dioxide adsorbents for adsorption. However, it is possible that some of the cerium dioxide may not be accessible to adsorption as a portion of this valuable chemical resides inside the particle itself. This study examines the efficacy of a new adsorbent synthesized such that cerium dioxide nanoparticles are coated over an alumina substrate in an attempt to reduce cost and improve adsorption efficiency. It is found that the coated alumina has fast adsorption rates (95% removed in 5 minutes)...

AMMONIA AND COD REMOVAL FROM SYNTHETIC LEACHATE USING RICE HUSK COMPOSITE ADSORBENT (doi: 10.4090/juee.2011.v5n1.024031)

Abdul Halim, Azhar; Zainal Abidin, Noor Nazurah; Awang, Normah; Ithnin, Anuar; Othman, Mohd. Sham; Wahab, Mohd. Ikram
Fonte: JUEE Press Publicador: JUEE Press
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 17/09/2011 ENG
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Ammonia and chemical oxygen demand (COD) were the most two problematic parameters in the landfill leachate. In this study, a new composite adsorbent derived from rice husk ash waste is evaluated with respect to its ability to remove these contaminants from synthetic leachate. Results indicate that the new composite adsorbent is able to adsorb both ammonia and COD. It has a higher adsorption capacity for ammonia (Q = 2.2578 mg/g) and an almost equal adsorption capacity for COD (Q = 2.8893) when compared with commercially activated carbon. The adsorption kinetics of this new product for ammonia and COD were primarily represented by the pseudo second-order mechanism. The overall adsorption rate of the ammonia and COD adsorption processes appears to be determined by chemisorption process. The regenerated composite adsorbent indicated higher adsorption capacities of ammonia and COD; 12.9366 mg/g and 3.1162 mg/g, respectively.