Navegando por Autor "Carvalho, Megg Madonyk Cota Elias"

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Aminated cellulose as a versatile adsorbent for batch removal of As(V) and Cu(II) from mono- and multicomponent aqueous solutions.
(2020) Pereira, Amanda Raimundi; Soares, Liliane Catone; Teodoro, Filipe Simões; Carvalho, Megg Madonyk Cota Elias; Ferreira, Gabriel Max Dias; Savedra, Ranylson Marcello Leal; Savedra, Melissa Fabíola Siqueira; Martineau Corcos, Charlotte; Silva, Luis Henrique Mendes da; Prim, Damien; Gurgel, Leandro Vinícius Alves
A bioadsorbent (CEDA) capable of adsorbing As(V) and Cu(II) simultaneously was prepared by tosylation of microcrystalline cellulose (MC) and nucleophilic substitution of the tosyl group by ethylenediamine. MC, tosyl cellulose, and CEDA were characterized by elemental C, H, N, and S analysis, infrared spectroscopy, and 13C solid-state nuclear magnetic resonance spectroscopy. The adsorption of As(V) and Cu (II) on CEDA was evaluated as a function of solution pH, contact time, and initial solute concentration. The maximum adsorption capacities of CEDA for As(V) and Cu(II) were 1.62 and 1.09 mmol g1 , respectively. The interactions of As(V) and Cu(II) with CEDA were elucidated using thermodynamic parameters, molecular quantum mechanics calculations, and experiments with ion exchange of Cd(II) by Cu(II), and As(V) by SO4 2. Adsorption enthalpies were determined as a function of surface coverage of the CEDA, using isothermal titration calorimetry, with DadsH values of 32.24 ± 0.07 and 93 ± 2 kJ mol1 obtained for As(V) and Cu(II), respectively. The potential to reuse CEDA was evaluated and the interference of other ions in the adsorption of As(V) and Cu(II) was investigated. Multi-component experiments showed that Cd(II), Co(II), Ni(II), and Pb(II) did not interfere in the adsorption of Cu(II), while SO4 2 inhibited As(V) adsorption.
Batch and continuous adsorption of Cd(II) and Pb(II) on polycarboxylated sugarcane bagasse.
(2023) Carvalho, Megg Madonyk Cota Elias; Soares, Liliane Catone; Maia, Luisa Cardoso; Taylor, Jason Guy; Herrera Adarme, Oscar Fernando; Ferreira, Gabriel Max Dias; Azevedo, Eduardo Ribeiro de; Siervo, Abner de; Silva, Luis Henrique Mendes da; Gurgel, Leandro Vinícius Alves
A bioadsorbent composed of polycarboxylated sugarcane bagasse (PSB) was prepared in a one-step reaction by the esterification of sugarcane bagasse hydroxyl groups with butane-1,2,3,4-tetracarboxylic dianhydride. 13C SS NMR measurements showed that 0.3 butane-1,2,3,4-tetracarboxylic acid units were grafted per cellobiose unit. PSB was used in the batch adsorption of Cd(II) and Pb(II) from mono-, bi-, and multicomponent aqueous solutions. For upscaling of the technology aiming at practical applications, evaluation was made of 4 cycles of continuous adsorption of Cd(II) and Pb(II) on PSB in a fixed-bed column. The maximum adsorption capacities for Cd(II) and Pb(II) on PSB in batch and continuous modes were 0.55 and 1.164 mmol g− 1 (62 and 241.2 mg g− 1 ), and 0.58 and 0.71 mmol g− 1 (65 and 153 mg g− 1 ), respectively. The standard adsorption enthalpy change (ΔadsH◦) values for Cd(II) and Pb(II) were 8.6 ± 0.5 and − 0.28 ± 0.03 kJ mol− 1 , respectively. The interactions involved in the adsorption of Cd(II) and Pb(II) on PSB were investigated. Multicomponent studies showed that Pb (II) and Cd(II) acted to suppress the adsorption of each other. In the presence of Cu(II) and Zn(II), the adsorption capacity followed the order: Pb(II) > Cu(II) > Cd(II) > Zn(II). Batch and continuous adsorption-desorption studies showed that PSB could be reused in at least 4 successive cycles, with desorption efficiencies of 88–100 %, which is essential for minimizing waste generation and reducing process costs.
Modeling mono- and multi-component adsorption of cobalt(II), copper(II), and nickel(II) metal ions from aqueous solution onto a new carboxylated sugarcane bagasse. Part I: Batch adsorption study.
(2015) Ramos, Stela Nhandeyara do Carmo; Xavier, Amália Luísa Pedrosa; Teodoro, Filipe Simões; Carvalho, Megg Madonyk Cota Elias; Gonçalves, Fernanda Jorge; Gil, Laurent Frédéric; Freitas, Rossimiriam Pereira de; Gurgel, Leandro Vinícius Alves
A new carboxylated-functionalized sugarcane bagasse (STA) was prepared through the esterification of sugarcane bagasse with trimellitic anhydride. The optimized synthesis conditions yield STA with a percent weight gain of 73.9% and the number of carboxylic acid groups accounted for 3.78 mmol/g. STA was characterized by FTIR, elemental analysis, TGA, PZC, and SEM. Adsorption kinetics followed a pseudosecond- order model. The adsorption rate constant showed the following order: k2,Ni 2+ > k2,Cu 2+ > k2,Co 2+. Four mono- and multi-component isotherm models were used to model the adsorption systems. Monocomponent experimental data were fitted to Langmuir and Sips models; whereas, multicomponent data were fitted to modified extended Langmuir and P-factor models. The maximum adsorption capacities (Qmax,mono) obtained from the Langmuir model were 1.140, 1.197, and 1.563 mmol/g for Co2+, Cu2+, and Ni2+, respectively. The competitive studies demonstrated that the multicomponent adsorption capacity (Qmax,multi) was smaller than Qmax,mono, as a result of the interaction between the metal ions. Desorption studies showed that all metal ions could be fully desorbed from STA.
Multivariate optimization applied to the synthesis and reuse of a new sugarcane bagasse‑based biosorbent to remove Cd(II) and Pb(II) from aqueous solutions.
(2022) Carvalho, Megg Madonyk Cota Elias; Soares, Liliane Catone; Maia, Luisa Cardoso; Dias, Mariana Viviane Lima; Gurgel, Leandro Vinícius Alves
This study reports the use of multivariate tools to optimize the synthesis of a new agricultural-based biosorbent derived from sugarcane bagasse (SB) for the removal of Cd(II) and Pb(II) from aqueous solutions, as well as to optimize the process of desorption of these ions from the spent biosorbent using an acidic solution. The efects of the reaction parameters temperature (T), time (t), and the ratio of 1,2,3,4-butanetetracarboxylic acid dianhydride (BTCAD) to raw SB (wBTCAD wraw SB −1) on the chemical modifcation of raw SB with BTCAD and on the equilibrium adsorption capacity (qe) for Cd(II) and Pb(II) were investigated by application of a 23 Doehlert experimental design (DED), followed by optimization using a statistical desirability tool to produce the best adsorbent in terms of performance and cost. The best reaction condition was wBTCAD wraw SB −1 of 4.0 g g−1, t of 1 h, and T of 70 ºC. The optimal synthesis condition resulted in a modifed sugarcane bagasse (MSB) that provided qe values for Cd(II) and Pb(II) of 0.50 and 0.61 mmol g−1, respectively, obtained under the following conditions: 0.311 mmol Cd(II) L−1, 0.632 mmol Pb(II) L−1, pH 5.0, 4 h, 0.2 g L−1 MSB, 130 rpm, and 25 °C. The desorption of Cd(II) and Pb(II) from MSB was investigated by a 22 DED, with optimization using the desirability tool to obtain the best desorption condition in terms of HNO3 solution concentration (퐶HNO3 ) and t. The desorption efciencies for Cd(II) and Pb(II) were 90±4% and 88±3%, respectively, obtained using 0.7 mol L−1 HNO3, t of 42 min, and 1.0 g L−1 MSB-M(II) (M=Pb or Cd). Infrared spectroscopy was used to investigate the natures of the interactions involved in the adsorption of Cd(II) and Pb(II) on MSB, as well as possible changes in the chemical structure of MSB after desorption. The synthesis of MSB can be performed under mild reaction conditions (t=1 h, T=70 ºC), and the solvents used can be recovered by distillation. BTCA is commercially available at moderate cost and can alternatively be obtained employing microbial succinic acid, metal-free catalysis, and modest use of petrochemical feedstocks. Furthermore, MSB can be reused, which could contribute to increasing the economic feasibility of water and wastewater treatment processes.
Quantification of moisture contents in iron and manganese ores.
(2013) Costa, Geraldo Magela da; Novack, Kátia Monteiro; Carvalho, Megg Madonyk Cota Elias; Cunha, Camila Cristina Rodrigues Ferreira da
The moisture contents of several synthetic and natural goethite-bearing samples were determined by the loss-of-mass method and by the Karl-Fischer titration. It was found that drying at 105°C did not remove all the water from these samples, and that temperatures above 200°C would be required to completely remove the adsorbed water. The multiple peaks observed in the TGA and DSC measurements are not due to the dehydroxylation of goethite, but are due to the release of adsorbed water. The decomposition of goethite into hematite occurs with the release of adsorbed water from room temperature up to the onset of the main dehydroxylation peak. The dehydroxylation occurs in a broad range of temperatures due to the existence of a particle-size distribution, surface hydroxyls and formation of a hematite coating. The determination of all adsorbed water is best performed by adding the powdered sample into the Karl- Fischer reaction vessel.
Síntese de um novo material adsorvente a base de bagaço de cana-de-açúcar para remoção de íons de metais pesados e corantes têxteis de soluções aquosas.
(2017) Carvalho, Megg Madonyk Cota Elias; Gurgel, Leandro Vinícius Alves; Ferreira, Gabriel Max Dias; Mageste, Aparecida Barbosa; Gurgel, Leandro Vinícius Alves; Alves, Rosemeire Brondi
A contaminação química dos recursos hídricos por contaminates orgânicos e inorgânicos tais como corantes têxteis e metais pesados vem despertando uma grande preocupação global devido aos problemas ambientais que a presença destes compostos causam. Devido aos métodos de tratamento físico-químicos e biológicos tradicionalmente empregados gerarem elevados custos, métodos alternativos como a adsorção empregando bioadsorventes vêm sendo estudados para substituir e/ou complementar tais métodos. Neste trabalho, o bagaço de cana-de-açúcar (BC) foi modificado com os anidridos ftálico e succicínico em uma síntese em uma única etapa (one pot). A síntese foi avaliada por meio de um planejamento fatorial 23, cujas variáveis independentes foram temperatura, tempo e fração molar de anidrido succínico (χAS) e as variáveis resposta foram as capacidades de adsorção dos corantes auramina-O (AO) e safranina-T (ST) e dos metais Co+2 e Ni+2 a fim de um melhor conhecimento do sistema. O perfil de desejabilidade indicou a melhor condição de síntese em 100°C, 660 min e χAS de 0,2 dentro do domínio experimental investigado e tal resultado foi satisfatório dentro da proposta deste estudo. O BC modificado foi caracterizado por ganho de massa, quantidade de funções ácidas, PCZ, análise elementar, FTIR, TGA/DTG, DRX, RMN 13C em estado sólido, MEV e EDX. Os estudos de adsorção monocomponente revelaram que o pH de melhor adsorção dos corantes foi 7,0 e dos metais foi 5,75. A adsorção dos corantes seguiu uma cinética de Elovich, enquanto a adsorção dos íons Co+2 e Ni+2 seguiu uma cinética de pseudo segunda ordem. As isotermas foram modeladas com os modelos de Langmuir, Sips, D-R e R-P. As capacidades máximas de adsorção encontradas experimentalmente foram 1,37, 0,93, 0,53 e 0,49 mmol/g para AO, ST, Co+2 e Ni+2, respectivamente. Medidas de titulação calorimétrica isotérmica foram feitas e as variações de entalpias de adsorção encontradas revelaram que a adsorção dos corantes foi um processo exotérmico e a de metais endotérmico. A energia livre de Gibbs calculada revelou que os corantes e metais concentraram-se preferencialmente na superfície do bagaço de cana modificado. Os estudos de adsorção de corantes com o BC in natura revelaram que a modificação química incrementou a capacidade adsortiva deste material. Estudos de dessorção e re-adsorção mostraram que é possível obter eficiências de dessorção superiores a 42%, 54%, 83% e 95% e de re-adsorção superiores a 98%, 76%, 90% e 100% para AO, ST, Co2+ e Ni2+, respectivamente, e, desta forma, revelaram que o BC modificado pode ser reutilizado sem perda de sua capacidade adsortiva e que o processo de dessorção usando solução ácida não é agressivo, nas condições empregadas, mantendo a integridade das fibras do material e sua funcionalidade química.
Synthesis and application of a new carboxylated cellulose derivative. Part I : removal of Co2+, Cu2+ and Ni2+ from monocomponent spiked aqueous solution.
(2016) Teodoro, Filipe Simões; Ramos, Stela Nhandeyara do Carmo; Carvalho, Megg Madonyk Cota Elias; Mageste, Aparecida Barbosa; Ferreira, Gabriel Max Dias; Silva, Luis Henrique Mendes da; Gil, Laurent Frédéric; Gurgel, Leandro Vinícius Alves
A new carboxylated cellulose derivative (CTA) was prepared from the esterification of cellulose with 1,2, 4-Benzenetricarboxylic anhydride. CTA was characterized by percent weight gain (pwg), amount of carboxylic acid groups (nCOOH), elemental analysis, FTIR, TGA, solid-state 13C NMR, X-ray diffraction (DRX), specific surface area, pore size distribution, SEM and EDX. The best CTA synthesis condition yielded a pwg and nCOOH of 94.5% and 6.81 mmol g 1, respectively. CTA was used as an adsorbent material to remove Co2+, Cu2+ and Ni2+ from monocomponent spiked aqueous solution. Adsorption studies were developed as a function of the solution pH, contact time and initial adsorbate concentration. Langmuir model better fitted the experimental adsorption data and the maximum adsorption capacities estimated by this model were 0.749, 1.487 and 1.001 mmol g 1 for Co2+, Cu2+ and Ni2+, respectively. The adsorption mechanism was investigated by using isothermal titration calorimetry. The values of DadsH were in the range from 5.36 to 8.09 kJ mol 1, suggesting that the mechanism controlling the phenomenon is physisorption. Desorption and re-adsorption studies were also performed. Desorption and re-adsorption efficiencies were closer to 100%, allowing the recovery of both metal ions and CTA adsorbent.
Synthesis and application of a new carboxylated cellulose derivative. Part III : removal of auramine-O and safranin-T from mono- and bi-component spiked aqueous solutions.
(2018) Teodoro, Filipe Simões; Carvalho, Megg Madonyk Cota Elias; Ferreira, Gabriel Max Dias; Herrera Adarme, Oscar Fernando; Savedra, Ranylson Marcello Leal; Savedra, Melissa Fabíola Siqueira; Silva, Luis Henrique Mendes da; Gil, Laurent Frédéric; Gurgel, Leandro Vinícius Alves
In the third part of this series of studies, the adsorption of the basic textile dyes auramine-O (AO) and safranin-T (ST) on a carboxylated cellulose derivative (CTA) were evaluated in mono- and bi-component spiked aqueous solutions. Adsorption studies were developed as a function of solution pH, contact time, and initial dye concentration. Adsorption kinetic data were modeled by monocomponent kinetic models of pseudo-first- (PFO), pseudo-second-order (PSO), intraparticle diffusion, and Boyd, while the competitive kinetic model of Corsel was used to model bicomponent kinetic data. Monocomponent adsorption equilibrium data were modeled by the Langmuir, Sips, Fowler-Guggenhein, Hill de-Boer, and Konda models, while the IAST and RAST models were used to model bicomponent equilibrium data. Monocomponent maximum adsorption capacities for AO and ST at pH 4.5 were 2.841 and 3.691 mmol g−1, and at pH 7.0 were 5.443 and 4.074 mmol g−1, respectively. Bicomponent maximum adsorption capacities for AO and ST at pH 7.0 were 1.230 and 3.728 mmol g−1. Adsorption enthalpy changes (ΔadsH) were obtained using isothermal titration calorimetry. The values of ΔadsH ranged from −18.83 to −5.60 kJ mol−1, suggesting that physisorption controlled the adsorption process. Desorption and re-adsorption of CTA was also evaluated.
Synthesis and application of sugarcane bagasse cellulose mixed esters. Part I : removal of Co2+ and Ni2+ from single spiked aqueous solutions in batch mode using sugarcane bagasse cellulose succinate phthalate.
(2019) Carvalho, Megg Madonyk Cota Elias; Ferreira, Gabriel Max Dias; Almeida, Francine Tatiane Rezende de; Rosa, Nathália Cristina Martins; Silva, Isabela Almeida; Filgueiras, Jefferson Gonçalves; Azevedo, Eduardo Ribeiro de; Silva, Luis Henrique Mendes da; Melo, Tânia Márcia Sacramento; Gil, Laurent Frédéric; Gurgel, Leandro Vinícius Alves
Sugarcane bagasse cellulose mixed ester succinate phthalate (SBSPh) was synthesized by a novel one-pot reaction method. The effects of temperature, time and mole fraction of succinic anhydride (χSA) on the responses weight gain (wg), number of carboxylic acid groups (nT,COOH), and adsorption capacity (q) of Co2+ and Ni2+ were evaluated by a 23 experimental design. The chemical structure of the material was elucidated by Fourier transform infrared, 13C Multiple Cross-Polarization solid-state NMR spectroscopy and 1H NMR relaxometry. The best SBSPh synthesis condition (100 °C, 11 h, χSA of 0.2) yielded a wg of 59.1%, nT,COOH of 3.41 mmol g−1, and values of qCo2+ and qNi2+ of 0.348 and 0.346 mmol g−1, respectively. The Sips model fitted better the equilibrium data, and the maximum adsorption capacities (pH 5.75 and 25 °C) estimated by this model were 0.62 and 0.53 mmol g−1 for Co2+ and Ni2+, respectively. The ΔadsH° values estimated by isothermal titration calorimetry were 8.43 and 7.79 kJ mol−1 for Co2+ and Ni2+, respectively. Desorption and re-adsorption efficiencies were evaluated by a 22 experimental design, which showed that SBSPh adsorbent can be recovered and reused without significant loss of adsorption capacity.
Synthesis and application of sugarcane bagasse cellulose mixed esters. Part II : removal of Co2+ and Ni2+ from single spiked aqueous solutions in batch and continuous mode.
(2019) Almeida, Francine Tatiane Rezende de; Carvalho, Megg Madonyk Cota Elias; Xavier, Amália Luísa Pedrosa; Ferreira, Gabriel Max Dias; Silva, Isabela Almeida; Filgueiras, Jefferson Gonçalves; Azevedo, Eduardo Ribeiro de; Silva, Luís Henrique Mendes da; Gil, Laurent Frédéric; Gurgel, Leandro Vinícius Alves
Sugarcane bagasse cellulose succinate trimellitate (SBST) was prepared by a one-pot synthesis method. The synthesis of this novel mixed ester was investigated by a 23-factorial design. The parameters investigated were time, temperature, and succinic anhydride mole fraction (χSA). The responses evaluated were the adsorption capacity (qCo2+ and qNi2+), weight gain (wg), and number of carboxylic acid groups (nT,COOH). 13C Multiple Cross-Polarization solid-state NMR spectroscopy, 1H NMR relaxometry, and Fourier-transform infrared spectroscopy were used to elucidate the SBST structure. The best SBST reaction conditions were 100 °C, 660 min, and χSA of 0.2, which yielded SBST with a wg of 57.1%, nT,COOH of 4.48 mmol g−1, and qCo2+ and qNi2+ of 0.900 and 0.963 mmol g−1, respectively. The maximum adsorption capacities (Qmax) (pH 5.75, 25 °C) estimated by the Redlich-Peterson model for Co2+ and Ni2+ were 1.16 and 1.29 mmol g−1. The ΔadsH° values for Co2+ and Ni2+ adsorption obtained by isothermal titration calorimetry were 8.03 and 6.94 kJ mol−1. Regeneration and reuse of SBST were investigated and the best conditions applied for fixed-bed column adsorption in five consecutive cycles. SBST was fully desorbed and Qmax values for Co2+ (0.95 mmol g−1) and Ni2+ (1.02 mmol g−1) were estimated using the Bohart-Adams model.