Selene Guelli Souza | Universidade Federal de Santa Catarina - UFSC (Federal University of Santa Catarina) (original) (raw)

Papers by Selene Guelli Souza

Research paper thumbnail of Numerical Solution of Mass Transfer and Momentum Equations in a Laminar Flow Wetted Wall Column

Latin American applied research Pesquisa aplicada latino americana = Investigación aplicada latinoamericana

ABSTRACT

Research paper thumbnail of Review about Applications of Biofilm in the Degradation of Contaminants in Industrial Effluents

Research paper thumbnail of Marine Macro-alga Sargassum cymosum as Electron Donor for Hexavalent Chromium Reduction to Trivalent State in Aqueous Solutions

Chemical Engineering Journal, 2015

Research paper thumbnail of Alternative Technologies applied in the Treatment of Textile Industry Effluents

Chapter 2 - Alternative Technologies applied in the Treatment of Textile Industry Effluents, Volu... more Chapter 2 - Alternative Technologies applied in the Treatment of Textile Industry Effluents, Volume 2, Book: Sustainable water management in the tropics and subtropics - and case studies in Brazil, ISBN 978-85-63337-21-4, Pages 25-50, Jaguarão/RS:Fundação Universidade Federal do Pampa, UNIKASSEL, PGCult-UFMA, 2011.

Research paper thumbnail of Modelo De Fechamento Para Densidade De Força Interfacial Do Modelo De Dois Fluidos Sem Decomposição De Forças Sobre a Interface

ABSTRACT RESUMO – A modelagem matemática de escoamentos multifásicos vem sendo desenvolvida e apr... more ABSTRACT RESUMO – A modelagem matemática de escoamentos multifásicos vem sendo desenvolvida e aprimorada nos últimos anos e, dentre as várias abordagens, assinala-se a formulação Euler-Euler que embasa o Modelo de Dois Fluidos. O problema de fechamento do modelo decorrente da promediação das equações instantâneas locais é comumente resolvido por meio da decomposição da densidade de força interfacial em diversos mecanismos: Arrasto, Massa Virtual, Sustentação, etc. Tais modelos tem grande sucesso nos sistemas para os quais foram desenvolvidos e calibrados, mas carecem de generalidade e aplicação ampla e irrestrita. O presente trabalho propõe uma solução alternativa ao problema de fechamento sem a decomposição e postulação de quais forças agem e de quais seriam os modelos que as descrevem. O modelo se propõe a descrever o efeito de todo o Tensor Tensão sobre a interface -a força resultante -deixando a cargo da própria física e dinâmica do escoamento definir como as fases se influenciam. Um caso de teste foi escolhido inicialmente onde se comparam a abordagem padrão e a proposta, resolvendo-se por meio de simulação numérica direta no código comercial ANSYS CFX a instabilidade de Rayleigh-Taylor. Os dados obtidos demonstram que a proposta, mesmo que ainda incipiente, apresenta-se como promissora, visto os resultados entre ambas as abordagens apresentarem boa concordância entre si e com a comparação experimental.

Research paper thumbnail of Determinação de parâmetros cinéticos da sinterização de revestimentos cerâmicos de monoqueima do tipo BIIa

Cerâmica, 2011

A produção de revestimentos cerâmicos pelo processo monoqueima é atualmente o mais difundido entr... more A produção de revestimentos cerâmicos pelo processo monoqueima é atualmente o mais difundido entre as empresas de cerâmica. O processo de queima está em constante evolução e adaptação à novos parâmetros, devido ao crescimento tecnológico e à diversificação dos produtos cerâmicos. É necessário entender o mecanismos envolvidos na queima de placas cerâmicas utilizando fornos a rolos, principalmente o desempenho térmico do equipamento e características técnicas dos revestimentos cerâmicos. Neste trabalho, um modelo matemático e um procedimento experimental foram aplicados para determinar a cinética de retração. Os parâmetros cinéticos foram determinados experimentalmente, utilizando pó industrial para obter corpos-de-prova de 80 x 20 x 2,3 mm³ queimados em forno elétrico laboratorial a rolo. A energia de ativação, Ea =178041 J/mol, o expoente do tempo "n" que determina o mecanismo de sinterização, n = 0,26285 e fator de freqüência, k0 = 44768 s-1 foram determinados depois de d...

Research paper thumbnail of Application of Individual and Simultaneous Ozonation and Adsorption Processes in Batch and Fixed-Bed Reactors for Phenol Removal

Ozone: Science & Engineering, 2012

Ozonation, adsorption onto activated carbon and catalytic ozonation in batch and in a fixed-bed r... more Ozonation, adsorption onto activated carbon and catalytic ozonation in batch and in a fixed-bed reactor for the removal/degradation of phenol and COD were investigated. In the case of batch ozonation the oxidation capacity was greater than 6.9 g of phenol/g O3, while the continuous ozonation system degraded 40% of the phenol and reduced the COD by 27.9%. The adsorption process

Research paper thumbnail of Influence of solvent addition on the physicochemical properties of Brazilian gasoline

Fuel, 2008

The influence of several solvents (anhydrous ethanol, white spirit, alkylbenzene AB9, diesel) on ... more The influence of several solvents (anhydrous ethanol, white spirit, alkylbenzene AB9, diesel) on the physicochemical parameters of gasoline was studied according to ASTM international standard methods. The parameters investigated (distillation curves, density, Reid vapor pressure) showed differentiated behavior, depending on the class of the solvent (oxygenated, light and heavy aliphatic, aromatic) and the quantity added to the gasoline. The azeotropic mixtures formed by ethanol and hydrocarbons showed a strong influence on the behavior of the distillation curves and the location of the point of a sudden change in temperature was shown to be a possible way to detect adulterations and determine the quantity of solvent added to the gasoline.

Research paper thumbnail of Prediction of effective diffusivity tensors for bulk diffusion with chemical reactions in porous media

Brazilian Journal of Chemical Engineering, 2007

In this paper, the volume averaging transport equations of two reactive processes in porous media... more In this paper, the volume averaging transport equations of two reactive processes in porous media are presented. The porous media are characterized by different length scales and the information describing the mass transfer mechanisms is transferred hierarchically between scales by applying the volume averaging method. This development provides the theoretical definition of effective transport coefficients, which can be predicted through solution of the closure problems. The theoretical calculation of effective diffusion tensors of the species in the particle pores is presented. Two closure problems are deduced through mathematical formulation of two different scales: microporous (process 1) and macroporous (process 2). In order to solve these closure problems, the volume finite method is used as the numerical methodology. Good agreement is verified between the numerical solutions obtained in this study and the data found in the literature for the closure problems considered.

Research paper thumbnail of Adsorption of Remazol Blue RR from Textile Effluents Using Azadirachta indica Leaf Powder as an Alternative Adsorbent

Adsorption Science & Technology, 2009

Adsorption is one of the techniques used for the effective removal of dyes from industrial efflue... more Adsorption is one of the techniques used for the effective removal of dyes from industrial effluents, but the adsorption efficiency depends on the choice of a suitable adsorbent. The aim of the present study was to investigate the use of Neem leaves as an alternative adsorbent for the removal of dyes present in textile effluents. The dyestuff studied was the reactive dye Remazol Blue RR. In order to obtain the best removal conditions, the influence of the following parameters was investigated: pH value of the aqueous solution, agitation, addition of sodium sulphate, temperature and adsorbent particle size. A good correlation was obtained when the Langmuir model was applied to fit the experimental data obtained for the concentration of solute adsorbed by the solid phase in terms of the equilibrium concentration of the fluid phase. The experimental data showed that 90% removal of Remazol Blue RR was achievable using Neem leaves as the adsorbent. Lanaset Blue 2R Acid 509.4 Maxilon Blue GRL Basic 438.0 Remazol Blue RR Reactive 950.0 View publication stats View publication stats

Research paper thumbnail of Adsorption of Remazol Blue RR from Textile Effluents Using Azadirachta indica Leaf Powder as an Alternative Adsorbent

Adsorption Science & Technology, 2009

Adsorption is one of the techniques used for the effective removal of dyes from industrial efflue... more Adsorption is one of the techniques used for the effective removal of dyes from industrial effluents, but the adsorption efficiency depends on the choice of a suitable adsorbent. The aim of the present study was to investigate the use of Neem leaves as an alternative adsorbent for the removal of dyes present in textile effluents. The dyestuff studied was the reactive dye Remazol Blue RR. In order to obtain the best removal conditions, the influence of the following parameters was investigated: pH value of the aqueous solution, agitation, addition of sodium sulphate, temperature and adsorbent particle size. A good correlation was obtained when the Langmuir model was applied to fit the experimental data obtained for the concentration of solute adsorbed by the solid phase in terms of the equilibrium concentration of the fluid phase. The experimental data showed that 90% removal of Remazol Blue RR was achievable using Neem leaves as the adsorbent. Lanaset Blue 2R Acid 509.4 Maxilon Blue GRL Basic 438.0 Remazol Blue RR Reactive 950.0 View publication stats View publication stats

Research paper thumbnail of Equilibrium and thermodynamic studies on biosorption of Pb(II) onto Candida albicans biomass

Journal of Hazardous Materials, 2009

Biosorption of Pb(II) ions from aqueous solutions was studied in a batch system by using Candida ... more Biosorption of Pb(II) ions from aqueous solutions was studied in a batch system by using Candida albicans. The optimum conditions of biosorption were determined by investigating the initial metal ion concentration, contact time, temperature, biosorbent dose and pH. The extent of metal ion removed increased with increasing contact time, initial metal ion concentration and temperature. Biosorption equilibrium time was observed in 30min. The Freundlich and Langmuir adsorption models were used for the mathematical description of biosorption equilibrium and isotherm constants were also evaluated. The maximum biosorption capacity of Pb(II) on C. albicans was determined as 828.50+/-1.05, 831.26+/-1.30 and 833.33+/-1.12mgg(-1), respectively, at different temperatures (25, 35 and 45 degrees C). Biosorption showed pseudo second-order rate kinetics at different initial concentration of Pb(II) and different temperatures. The activation energy of the biosorption (Ea) was estimated as 59.04kJmol(...

Research paper thumbnail of A two-fluid model with a tensor closure model approach for free surface flow simulations

An interfacial closure model for twofluid model with a tensor approach is proposed. Well-known te... more An interfacial closure model for twofluid model with a tensor approach is proposed. Well-known test cases on freesurface problems were used for model validation. Calculation of the drag coefficients are in good agreement with classic formulation. Experimental data from dam break problem were well described with the tensor model. The model can also be used to calculate the drag coefficient in the classical approach.

Research paper thumbnail of Photochemical UVC/H2O2 Oxidation System as an Effective Method for the Decolourisation of Bio-Treated Textile Wastewaters: Towards Onsite Water Reuse

A photochemical UVC/H2O2 oxidation system was applied for the decolourisation of two real textile... more A photochemical UVC/H2O2 oxidation system was applied for the decolourisation of two real textile wastewaters, textile wastewater A – TWA and textile wastewater B - TWB - collected after biological oxidation from two different textile wastewater treatment plants. The photochemical oxidation assays were performed in a lab-scale photo-reactor, where a borosilicate tube is associated to an internal concentric quartz tube filled with a UVC lamp (6W). Photochemical reaction rates were determined under different operational conditions: H2O2 dosage (0-40 mM), pH (3, 5 and 9) and temperature (15, 23 and 35°C). For both TWA and TWB, it was observed a positive influence on the UVC/H2O2 efficiency at higher hydrogen peroxide dosages and wastewater temperature. However, the pH conditions differently affected each wastewater. Although the dissolved organic content remained almost similar during the UVC/H2O2 reaction period, the biodegradable organic fraction increased for values higher than 40%. To achieve the colour discharge limits imposed by the Brazilian regulations, it was necessary 180/75 min of UVC irradiation (8.3/3.4 kJUVC L-1) using an H2O2 dose of 25.0 mM, natural pH of 8.1/7.7 and T = 23 °C, respectively for the TWA/TWB. The photochemical-treated textile wastewater – PTWB was used as bathwater during bleaching and dyeing of cotton fibres in order to assess its onsite reuse in the textile manufacturing process. Compared with the same bleaching process made with distilled water, all quality indicators monitored showed small differences, which demonstrate the possible reuse of PTWB in this process. Finally, reuse of PTWB mixed with 50% distilled water as bathwater in the dyeing process with Direct Blue 71 resulted in similar samples (ΔE* = 0.76) when compared with standard dyeing process.

Research paper thumbnail of Water Reuse and Wastewater Minimization in Chemical Industries Using Differentiated Regeneration of Contaminants

Industrial & Engineering Chemistry Research, 2011

There is currently a great demand for tools that allow the analysis of water networks in a practi... more There is currently a great demand for tools that allow the analysis of water networks in a practical and objective way. In the modern scenarios chemical industries need to consume water in more rational forms to minimize the risk of water scarcity caused by pollution. Some of the alternatives for reducing water consumption involve the reuse and/or recycling of wastewater, such as the methodology based on the water source diagram (WSD), which is a flexible and dynamic alternative approach to generating viable scenarios for the management of water networks. In this study the implementation of the WSD to support the optimization software (GAMS) in a process of differentiated regeneration is studied, treating the operation of a chemical process of interest in an objective and systemic way. The method can be applied to resource networks with multiple impurities, even when the utility contains impurities. The possibilities for maximum reuse of water and differentiated effluent regeneration are studied, aiming to minimize the total flow of wastewater being treated inside the treatment units and the global cost of the network. The application of this methodology is illustrated through two case studies. The results show that this procedure allows the successful identification of different scenarios which present a condition of minimum water consumption together with a minimum network operation cost.

Research paper thumbnail of Analysis of the Behavior of the Simulated Moving Bed Reactor in the Sucrose Inversion Process

Http Dx Doi Org 10 1080 01496390500267426, Feb 15, 2007

ABSTRACT

Research paper thumbnail of Eficiência do Inchamento de Borrachas Vulcanizadas na Detecção de Adulterantes em Gasolina

ABSTRACT Revista Petro & Química, ISSN 0101-5397, Edição 345, Pages 57-60, 2012.

Research paper thumbnail of Influence of solvent addition on the physicochemical properties of Brazilian gasoline

Fuel, Aug 1, 2008

The influence of several solvents (anhydrous ethanol, white spirit, alkylbenzene AB9, diesel) on ... more The influence of several solvents (anhydrous ethanol, white spirit, alkylbenzene AB9, diesel) on the physicochemical parameters of gasoline was studied according to ASTM international standard methods. The parameters investigated (distillation curves, density, Reid vapor pressure) showed differentiated behavior, depending on the class of the solvent (oxygenated, light and heavy aliphatic, aromatic) and the quantity added to the gasoline. The azeotropic mixtures formed by ethanol and hydrocarbons showed a strong influence on the behavior of the distillation curves and the location of the point of a sudden change in temperature was shown to be a possible way to detect adulterations and determine the quantity of solvent added to the gasoline.

Research paper thumbnail of Quantification of styrene-butadiene rubber swelling as a function of the toluene content in gasoline: A new method to detect adulterations of fuels

Journal of Applied Polymer Science, 2013

The swelling of styrene-butadiene rubber (SBR) when exposed to organic solvents was measured and ... more The swelling of styrene-butadiene rubber (SBR) when exposed to organic solvents was measured and mathematically correlated to the toluene concentration in a complex mixture such as gasoline. This relation enables inferences to be made regarding the composition and quality criteria of the fuel and represents a new method to detect adulterations. Changes in the mass and volume were measured by gravimetric and hydrostatic techniques. A simplex-lattice experimental mixture design was carried out in mixtures with toluene, heptane, and type C gasoline (a blend of gasoline with ethanol) and the mass swelling was statically analyzed for 5 and 15 min of continuous immersion in the mixtures of the solvents. For the experimental design two cubic equations were obtained with a high value for R 2 -ajusted (>0.98) at 25 C 6 1 C correlating mass swelling of SBR and the content of solvents. For both immersion times, the greatest and most important effect over the mass swelling was the content of toluene, with the mass variations increasing proportionally with toluene content in the gasoline. The analysis of variance applied to the mass swelling data verified that it is possible to obtain good mathematical equations to associate the rubber swelling with the solvent composition and concentration.

Research paper thumbnail of Patente – Processo e Dispositivo de Detecção de Adulterantes em Fluidos

Patente – Processo e Dispositivo de Detecção de Adulterantes em Fluidos, Patente, Privilégio de I... more Patente – Processo e Dispositivo de Detecção de Adulterantes em Fluidos, Patente, Privilégio de Inovação número 221003401567, Patente INPI PI 017100001128, 28 de Julho de 2010 (Depósito).

Research paper thumbnail of Numerical Solution of Mass Transfer and Momentum Equations in a Laminar Flow Wetted Wall Column

Latin American applied research Pesquisa aplicada latino americana = Investigación aplicada latinoamericana

ABSTRACT

Research paper thumbnail of Review about Applications of Biofilm in the Degradation of Contaminants in Industrial Effluents

Research paper thumbnail of Marine Macro-alga Sargassum cymosum as Electron Donor for Hexavalent Chromium Reduction to Trivalent State in Aqueous Solutions

Chemical Engineering Journal, 2015

Research paper thumbnail of Alternative Technologies applied in the Treatment of Textile Industry Effluents

Chapter 2 - Alternative Technologies applied in the Treatment of Textile Industry Effluents, Volu... more Chapter 2 - Alternative Technologies applied in the Treatment of Textile Industry Effluents, Volume 2, Book: Sustainable water management in the tropics and subtropics - and case studies in Brazil, ISBN 978-85-63337-21-4, Pages 25-50, Jaguarão/RS:Fundação Universidade Federal do Pampa, UNIKASSEL, PGCult-UFMA, 2011.

Research paper thumbnail of Modelo De Fechamento Para Densidade De Força Interfacial Do Modelo De Dois Fluidos Sem Decomposição De Forças Sobre a Interface

ABSTRACT RESUMO – A modelagem matemática de escoamentos multifásicos vem sendo desenvolvida e apr... more ABSTRACT RESUMO – A modelagem matemática de escoamentos multifásicos vem sendo desenvolvida e aprimorada nos últimos anos e, dentre as várias abordagens, assinala-se a formulação Euler-Euler que embasa o Modelo de Dois Fluidos. O problema de fechamento do modelo decorrente da promediação das equações instantâneas locais é comumente resolvido por meio da decomposição da densidade de força interfacial em diversos mecanismos: Arrasto, Massa Virtual, Sustentação, etc. Tais modelos tem grande sucesso nos sistemas para os quais foram desenvolvidos e calibrados, mas carecem de generalidade e aplicação ampla e irrestrita. O presente trabalho propõe uma solução alternativa ao problema de fechamento sem a decomposição e postulação de quais forças agem e de quais seriam os modelos que as descrevem. O modelo se propõe a descrever o efeito de todo o Tensor Tensão sobre a interface -a força resultante -deixando a cargo da própria física e dinâmica do escoamento definir como as fases se influenciam. Um caso de teste foi escolhido inicialmente onde se comparam a abordagem padrão e a proposta, resolvendo-se por meio de simulação numérica direta no código comercial ANSYS CFX a instabilidade de Rayleigh-Taylor. Os dados obtidos demonstram que a proposta, mesmo que ainda incipiente, apresenta-se como promissora, visto os resultados entre ambas as abordagens apresentarem boa concordância entre si e com a comparação experimental.

Research paper thumbnail of Determinação de parâmetros cinéticos da sinterização de revestimentos cerâmicos de monoqueima do tipo BIIa

Cerâmica, 2011

A produção de revestimentos cerâmicos pelo processo monoqueima é atualmente o mais difundido entr... more A produção de revestimentos cerâmicos pelo processo monoqueima é atualmente o mais difundido entre as empresas de cerâmica. O processo de queima está em constante evolução e adaptação à novos parâmetros, devido ao crescimento tecnológico e à diversificação dos produtos cerâmicos. É necessário entender o mecanismos envolvidos na queima de placas cerâmicas utilizando fornos a rolos, principalmente o desempenho térmico do equipamento e características técnicas dos revestimentos cerâmicos. Neste trabalho, um modelo matemático e um procedimento experimental foram aplicados para determinar a cinética de retração. Os parâmetros cinéticos foram determinados experimentalmente, utilizando pó industrial para obter corpos-de-prova de 80 x 20 x 2,3 mm³ queimados em forno elétrico laboratorial a rolo. A energia de ativação, Ea =178041 J/mol, o expoente do tempo "n" que determina o mecanismo de sinterização, n = 0,26285 e fator de freqüência, k0 = 44768 s-1 foram determinados depois de d...

Research paper thumbnail of Application of Individual and Simultaneous Ozonation and Adsorption Processes in Batch and Fixed-Bed Reactors for Phenol Removal

Ozone: Science & Engineering, 2012

Ozonation, adsorption onto activated carbon and catalytic ozonation in batch and in a fixed-bed r... more Ozonation, adsorption onto activated carbon and catalytic ozonation in batch and in a fixed-bed reactor for the removal/degradation of phenol and COD were investigated. In the case of batch ozonation the oxidation capacity was greater than 6.9 g of phenol/g O3, while the continuous ozonation system degraded 40% of the phenol and reduced the COD by 27.9%. The adsorption process

Research paper thumbnail of Influence of solvent addition on the physicochemical properties of Brazilian gasoline

Fuel, 2008

The influence of several solvents (anhydrous ethanol, white spirit, alkylbenzene AB9, diesel) on ... more The influence of several solvents (anhydrous ethanol, white spirit, alkylbenzene AB9, diesel) on the physicochemical parameters of gasoline was studied according to ASTM international standard methods. The parameters investigated (distillation curves, density, Reid vapor pressure) showed differentiated behavior, depending on the class of the solvent (oxygenated, light and heavy aliphatic, aromatic) and the quantity added to the gasoline. The azeotropic mixtures formed by ethanol and hydrocarbons showed a strong influence on the behavior of the distillation curves and the location of the point of a sudden change in temperature was shown to be a possible way to detect adulterations and determine the quantity of solvent added to the gasoline.

Research paper thumbnail of Prediction of effective diffusivity tensors for bulk diffusion with chemical reactions in porous media

Brazilian Journal of Chemical Engineering, 2007

In this paper, the volume averaging transport equations of two reactive processes in porous media... more In this paper, the volume averaging transport equations of two reactive processes in porous media are presented. The porous media are characterized by different length scales and the information describing the mass transfer mechanisms is transferred hierarchically between scales by applying the volume averaging method. This development provides the theoretical definition of effective transport coefficients, which can be predicted through solution of the closure problems. The theoretical calculation of effective diffusion tensors of the species in the particle pores is presented. Two closure problems are deduced through mathematical formulation of two different scales: microporous (process 1) and macroporous (process 2). In order to solve these closure problems, the volume finite method is used as the numerical methodology. Good agreement is verified between the numerical solutions obtained in this study and the data found in the literature for the closure problems considered.

Research paper thumbnail of Adsorption of Remazol Blue RR from Textile Effluents Using Azadirachta indica Leaf Powder as an Alternative Adsorbent

Adsorption Science & Technology, 2009

Adsorption is one of the techniques used for the effective removal of dyes from industrial efflue... more Adsorption is one of the techniques used for the effective removal of dyes from industrial effluents, but the adsorption efficiency depends on the choice of a suitable adsorbent. The aim of the present study was to investigate the use of Neem leaves as an alternative adsorbent for the removal of dyes present in textile effluents. The dyestuff studied was the reactive dye Remazol Blue RR. In order to obtain the best removal conditions, the influence of the following parameters was investigated: pH value of the aqueous solution, agitation, addition of sodium sulphate, temperature and adsorbent particle size. A good correlation was obtained when the Langmuir model was applied to fit the experimental data obtained for the concentration of solute adsorbed by the solid phase in terms of the equilibrium concentration of the fluid phase. The experimental data showed that 90% removal of Remazol Blue RR was achievable using Neem leaves as the adsorbent. Lanaset Blue 2R Acid 509.4 Maxilon Blue GRL Basic 438.0 Remazol Blue RR Reactive 950.0 View publication stats View publication stats

Research paper thumbnail of Adsorption of Remazol Blue RR from Textile Effluents Using Azadirachta indica Leaf Powder as an Alternative Adsorbent

Adsorption Science & Technology, 2009

Adsorption is one of the techniques used for the effective removal of dyes from industrial efflue... more Adsorption is one of the techniques used for the effective removal of dyes from industrial effluents, but the adsorption efficiency depends on the choice of a suitable adsorbent. The aim of the present study was to investigate the use of Neem leaves as an alternative adsorbent for the removal of dyes present in textile effluents. The dyestuff studied was the reactive dye Remazol Blue RR. In order to obtain the best removal conditions, the influence of the following parameters was investigated: pH value of the aqueous solution, agitation, addition of sodium sulphate, temperature and adsorbent particle size. A good correlation was obtained when the Langmuir model was applied to fit the experimental data obtained for the concentration of solute adsorbed by the solid phase in terms of the equilibrium concentration of the fluid phase. The experimental data showed that 90% removal of Remazol Blue RR was achievable using Neem leaves as the adsorbent. Lanaset Blue 2R Acid 509.4 Maxilon Blue GRL Basic 438.0 Remazol Blue RR Reactive 950.0 View publication stats View publication stats

Research paper thumbnail of Equilibrium and thermodynamic studies on biosorption of Pb(II) onto Candida albicans biomass

Journal of Hazardous Materials, 2009

Biosorption of Pb(II) ions from aqueous solutions was studied in a batch system by using Candida ... more Biosorption of Pb(II) ions from aqueous solutions was studied in a batch system by using Candida albicans. The optimum conditions of biosorption were determined by investigating the initial metal ion concentration, contact time, temperature, biosorbent dose and pH. The extent of metal ion removed increased with increasing contact time, initial metal ion concentration and temperature. Biosorption equilibrium time was observed in 30min. The Freundlich and Langmuir adsorption models were used for the mathematical description of biosorption equilibrium and isotherm constants were also evaluated. The maximum biosorption capacity of Pb(II) on C. albicans was determined as 828.50+/-1.05, 831.26+/-1.30 and 833.33+/-1.12mgg(-1), respectively, at different temperatures (25, 35 and 45 degrees C). Biosorption showed pseudo second-order rate kinetics at different initial concentration of Pb(II) and different temperatures. The activation energy of the biosorption (Ea) was estimated as 59.04kJmol(...

Research paper thumbnail of A two-fluid model with a tensor closure model approach for free surface flow simulations

An interfacial closure model for twofluid model with a tensor approach is proposed. Well-known te... more An interfacial closure model for twofluid model with a tensor approach is proposed. Well-known test cases on freesurface problems were used for model validation. Calculation of the drag coefficients are in good agreement with classic formulation. Experimental data from dam break problem were well described with the tensor model. The model can also be used to calculate the drag coefficient in the classical approach.

Research paper thumbnail of Photochemical UVC/H2O2 Oxidation System as an Effective Method for the Decolourisation of Bio-Treated Textile Wastewaters: Towards Onsite Water Reuse

A photochemical UVC/H2O2 oxidation system was applied for the decolourisation of two real textile... more A photochemical UVC/H2O2 oxidation system was applied for the decolourisation of two real textile wastewaters, textile wastewater A – TWA and textile wastewater B - TWB - collected after biological oxidation from two different textile wastewater treatment plants. The photochemical oxidation assays were performed in a lab-scale photo-reactor, where a borosilicate tube is associated to an internal concentric quartz tube filled with a UVC lamp (6W). Photochemical reaction rates were determined under different operational conditions: H2O2 dosage (0-40 mM), pH (3, 5 and 9) and temperature (15, 23 and 35°C). For both TWA and TWB, it was observed a positive influence on the UVC/H2O2 efficiency at higher hydrogen peroxide dosages and wastewater temperature. However, the pH conditions differently affected each wastewater. Although the dissolved organic content remained almost similar during the UVC/H2O2 reaction period, the biodegradable organic fraction increased for values higher than 40%. To achieve the colour discharge limits imposed by the Brazilian regulations, it was necessary 180/75 min of UVC irradiation (8.3/3.4 kJUVC L-1) using an H2O2 dose of 25.0 mM, natural pH of 8.1/7.7 and T = 23 °C, respectively for the TWA/TWB. The photochemical-treated textile wastewater – PTWB was used as bathwater during bleaching and dyeing of cotton fibres in order to assess its onsite reuse in the textile manufacturing process. Compared with the same bleaching process made with distilled water, all quality indicators monitored showed small differences, which demonstrate the possible reuse of PTWB in this process. Finally, reuse of PTWB mixed with 50% distilled water as bathwater in the dyeing process with Direct Blue 71 resulted in similar samples (ΔE* = 0.76) when compared with standard dyeing process.

Research paper thumbnail of Water Reuse and Wastewater Minimization in Chemical Industries Using Differentiated Regeneration of Contaminants

Industrial & Engineering Chemistry Research, 2011

There is currently a great demand for tools that allow the analysis of water networks in a practi... more There is currently a great demand for tools that allow the analysis of water networks in a practical and objective way. In the modern scenarios chemical industries need to consume water in more rational forms to minimize the risk of water scarcity caused by pollution. Some of the alternatives for reducing water consumption involve the reuse and/or recycling of wastewater, such as the methodology based on the water source diagram (WSD), which is a flexible and dynamic alternative approach to generating viable scenarios for the management of water networks. In this study the implementation of the WSD to support the optimization software (GAMS) in a process of differentiated regeneration is studied, treating the operation of a chemical process of interest in an objective and systemic way. The method can be applied to resource networks with multiple impurities, even when the utility contains impurities. The possibilities for maximum reuse of water and differentiated effluent regeneration are studied, aiming to minimize the total flow of wastewater being treated inside the treatment units and the global cost of the network. The application of this methodology is illustrated through two case studies. The results show that this procedure allows the successful identification of different scenarios which present a condition of minimum water consumption together with a minimum network operation cost.

Research paper thumbnail of Analysis of the Behavior of the Simulated Moving Bed Reactor in the Sucrose Inversion Process

Http Dx Doi Org 10 1080 01496390500267426, Feb 15, 2007

ABSTRACT

Research paper thumbnail of Eficiência do Inchamento de Borrachas Vulcanizadas na Detecção de Adulterantes em Gasolina

ABSTRACT Revista Petro & Química, ISSN 0101-5397, Edição 345, Pages 57-60, 2012.

Research paper thumbnail of Influence of solvent addition on the physicochemical properties of Brazilian gasoline

Fuel, Aug 1, 2008

The influence of several solvents (anhydrous ethanol, white spirit, alkylbenzene AB9, diesel) on ... more The influence of several solvents (anhydrous ethanol, white spirit, alkylbenzene AB9, diesel) on the physicochemical parameters of gasoline was studied according to ASTM international standard methods. The parameters investigated (distillation curves, density, Reid vapor pressure) showed differentiated behavior, depending on the class of the solvent (oxygenated, light and heavy aliphatic, aromatic) and the quantity added to the gasoline. The azeotropic mixtures formed by ethanol and hydrocarbons showed a strong influence on the behavior of the distillation curves and the location of the point of a sudden change in temperature was shown to be a possible way to detect adulterations and determine the quantity of solvent added to the gasoline.

Research paper thumbnail of Quantification of styrene-butadiene rubber swelling as a function of the toluene content in gasoline: A new method to detect adulterations of fuels

Journal of Applied Polymer Science, 2013

The swelling of styrene-butadiene rubber (SBR) when exposed to organic solvents was measured and ... more The swelling of styrene-butadiene rubber (SBR) when exposed to organic solvents was measured and mathematically correlated to the toluene concentration in a complex mixture such as gasoline. This relation enables inferences to be made regarding the composition and quality criteria of the fuel and represents a new method to detect adulterations. Changes in the mass and volume were measured by gravimetric and hydrostatic techniques. A simplex-lattice experimental mixture design was carried out in mixtures with toluene, heptane, and type C gasoline (a blend of gasoline with ethanol) and the mass swelling was statically analyzed for 5 and 15 min of continuous immersion in the mixtures of the solvents. For the experimental design two cubic equations were obtained with a high value for R 2 -ajusted (>0.98) at 25 C 6 1 C correlating mass swelling of SBR and the content of solvents. For both immersion times, the greatest and most important effect over the mass swelling was the content of toluene, with the mass variations increasing proportionally with toluene content in the gasoline. The analysis of variance applied to the mass swelling data verified that it is possible to obtain good mathematical equations to associate the rubber swelling with the solvent composition and concentration.

Research paper thumbnail of Patente – Processo e Dispositivo de Detecção de Adulterantes em Fluidos

Patente – Processo e Dispositivo de Detecção de Adulterantes em Fluidos, Patente, Privilégio de I... more Patente – Processo e Dispositivo de Detecção de Adulterantes em Fluidos, Patente, Privilégio de Inovação número 221003401567, Patente INPI PI 017100001128, 28 de Julho de 2010 (Depósito).