Dépouillements

Natural gas treating by selective adsorption / Marco Tagliabue in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 553-566 Titre : Natural gas treating by selective adsorption : material science and chemical engineering interplay Type de document : texte imprimé Auteurs : Marco Tagliabue, Auteur ; David Farrusseng, Auteur ; Susana Valencia, Auteur Année de publication : 2010 Article en page(s) : pp. 553-566 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Natural  gas  Methane  Carbon  dioxide  rejection  Nitrogen  rejection  Pressure  swing  adsorption  Zeolite  Carbons  Metal  open  framework  MOF Index. décimale : 660 Résumé : The paper addresses current needs in Natural Gas (NG) treating. Basic principles of Pressure Swing Adsorption (PSA) separation processes are described. A state of the art of microporous adsorbents in the frame of NG treating is given. It includes reference and advanced zeolites, carbon based materials and Metal-Organic Frameworks (MOFs). The pros and cons of each material category are discussed. Guidelines to develop on-purpose materials are given from thermodynamics and material state of the art. Finally, PSA applicability to inert (nitrogen and carbon dioxide) rejection from NG is discussed. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X6MT2Y-1&_user=6 [...] [article] Natural gas treating by selective adsorption : material science and chemical engineering interplay [texte imprimé] / Marco Tagliabue, Auteur ; David Farrusseng, Auteur ; Susana Valencia, Auteur . - 2010 . - pp. 553-566. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 553-566 Mots-clés : Natural  gas  Methane  Carbon  dioxide  rejection  Nitrogen  rejection  Pressure  swing  adsorption  Zeolite  Carbons  Metal  open  framework  MOF Index. décimale : 660 Résumé : The paper addresses current needs in Natural Gas (NG) treating. Basic principles of Pressure Swing Adsorption (PSA) separation processes are described. A state of the art of microporous adsorbents in the frame of NG treating is given. It includes reference and advanced zeolites, carbon based materials and Metal-Organic Frameworks (MOFs). The pros and cons of each material category are discussed. Guidelines to develop on-purpose materials are given from thermodynamics and material state of the art. Finally, PSA applicability to inert (nitrogen and carbon dioxide) rejection from NG is discussed. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X6MT2Y-1&_user=6 [...]

Multistage optimization of the adsorption of methylene blue dye onto defatted Carica papaya seeds / Emmanuel I. Unuabonah in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 567-579 Titre : Multistage optimization of the adsorption of methylene blue dye onto defatted Carica papaya seeds Type de document : texte imprimé Auteurs : Emmanuel I. Unuabonah, Auteur ; Gilbert U. Adie, Auteur ; Lora O. Onah, Auteur Année de publication : 2010 Article en page(s) : pp. 567-579 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Surface  chemistry  Kinetic  rate  Optimization  Carica  papaya  Adsorption  stages  Methylene  blue Index. décimale : 660 Résumé : Carica papaya seeds were defatted and used for the adsorption of methylene blue dye (MB dye). The pHPZC and specific surface area (SSA) of the defatted and undefatted Carica papaya seeds were found to be 6.25 and 143.27 m2 g−1 respectively. The adsorption capacities of the defatted Carica papaya seeds were 1250 and 769.23 mg g−1. Fourier transformed infrared (FT-IR) spectra analysis of defatted seeds suggests the presence of α,β-unsaturated ketone, β-keto (enolic) esters and lactones, quinones and carboxylic acids which were absent in the undefatted sample. The presence of carboxylic acid, phenolic and lactone functional groups were confirmed by surface chemistry studies. Adsorption of MB dye onto DPS adsorbent was found to be exothermic and spontaneous. FT-IR spectra of various particle sizes indicate the presence of functional groups on every particle size necessary for the adsorption of MB dye. Pseudo-second-order kinetic rate constant increased with increasing initial MB dye concentration. The adsorption reaction was observed to be very fast perhaps because of the presence of multiple functional groups with some of them having lone pair of electrons. Increasing pH was observed to have very little positive effect on the adsorption of MB dye on DPS adsorbent. Increasing particle size decreased the adsorption capacity of DPS adsorbent for MB dye. It is suggested that the mechanism for the adsorption of MB dye onto DPS adsorbent might not only be solely controlled by film diffusion but also by pore diffusion. Mathematical models for the optimization of adsorbent dose, number of adsorption stages and minimum contact time were developed. The optimum conditions for the adsorption of 99% of 100 mg L−1 MB dye from 10 m3 of aqueous solution of the dye were five adsorption stages, ≈21 kg for each stage with a total minimum contact time of ≈71 min. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4WS2J2M-4&_user=6 [...] [article] Multistage optimization of the adsorption of methylene blue dye onto defatted Carica papaya seeds [texte imprimé] / Emmanuel I. Unuabonah, Auteur ; Gilbert U. Adie, Auteur ; Lora O. Onah, Auteur . - 2010 . - pp. 567-579. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 567-579 Mots-clés : Surface  chemistry  Kinetic  rate  Optimization  Carica  papaya  Adsorption  stages  Methylene  blue Index. décimale : 660 Résumé : Carica papaya seeds were defatted and used for the adsorption of methylene blue dye (MB dye). The pHPZC and specific surface area (SSA) of the defatted and undefatted Carica papaya seeds were found to be 6.25 and 143.27 m2 g−1 respectively. The adsorption capacities of the defatted Carica papaya seeds were 1250 and 769.23 mg g−1. Fourier transformed infrared (FT-IR) spectra analysis of defatted seeds suggests the presence of α,β-unsaturated ketone, β-keto (enolic) esters and lactones, quinones and carboxylic acids which were absent in the undefatted sample. The presence of carboxylic acid, phenolic and lactone functional groups were confirmed by surface chemistry studies. Adsorption of MB dye onto DPS adsorbent was found to be exothermic and spontaneous. FT-IR spectra of various particle sizes indicate the presence of functional groups on every particle size necessary for the adsorption of MB dye. Pseudo-second-order kinetic rate constant increased with increasing initial MB dye concentration. The adsorption reaction was observed to be very fast perhaps because of the presence of multiple functional groups with some of them having lone pair of electrons. Increasing pH was observed to have very little positive effect on the adsorption of MB dye on DPS adsorbent. Increasing particle size decreased the adsorption capacity of DPS adsorbent for MB dye. It is suggested that the mechanism for the adsorption of MB dye onto DPS adsorbent might not only be solely controlled by film diffusion but also by pore diffusion. Mathematical models for the optimization of adsorbent dose, number of adsorption stages and minimum contact time were developed. The optimum conditions for the adsorption of 99% of 100 mg L−1 MB dye from 10 m3 of aqueous solution of the dye were five adsorption stages, ≈21 kg for each stage with a total minimum contact time of ≈71 min. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4WS2J2M-4&_user=6 [...]

Sorption studies of 134Cs, 60Co and 152+154Eu on phosphoric acid activated silico-antimonate crystals in high acidic media / Ismail M. Ali in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 580-585 Titre : Sorption studies of 134Cs, 60Co and 152+154Eu on phosphoric acid activated silico-antimonate crystals in high acidic media Type de document : texte imprimé Auteurs : Ismail M. Ali, Auteur Année de publication : 2010 Article en page(s) : pp. 580-585 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Silico-antimonate  Phosphoric  acid  activation  Sorption  kinetics Index. décimale : 660 Résumé : This work describes the sorption of 134Cs, 60Co and 152+154Eu by crystals of unmodified and phosphoric acid modified silico-antimonates (SiSb). Equilibrium and selectivity sequence for co-exiting metal ions under strongly acidic conditions of HClO4, H2SO4, HNO3 and HCl were investigated. The results showed that the silico-antimonate either in the high Sb5+ content or in the phosphated form possesses acidic characters and shows cation-exchange properties more efficient in acidic media. Kinetic studies indicated that pseudo-second-order model gave better fitting parameters comparing to that of pseudo-first-order one. The thermodynamic parameters of the sorption processes revealed spontaneous and endothermic nature. High negativity of ΔG° values for the modified SiSb confirms the positive role of phosphoric acid impregnation in the sorption process. The break-through capacities of the studied ions were further calculated from a column investigation. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4WXHC0N-4&_user=6 [...] [article] Sorption studies of 134Cs, 60Co and 152+154Eu on phosphoric acid activated silico-antimonate crystals in high acidic media [texte imprimé] / Ismail M. Ali, Auteur . - 2010 . - pp. 580-585. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 580-585 Mots-clés : Silico-antimonate  Phosphoric  acid  activation  Sorption  kinetics Index. décimale : 660 Résumé : This work describes the sorption of 134Cs, 60Co and 152+154Eu by crystals of unmodified and phosphoric acid modified silico-antimonates (SiSb). Equilibrium and selectivity sequence for co-exiting metal ions under strongly acidic conditions of HClO4, H2SO4, HNO3 and HCl were investigated. The results showed that the silico-antimonate either in the high Sb5+ content or in the phosphated form possesses acidic characters and shows cation-exchange properties more efficient in acidic media. Kinetic studies indicated that pseudo-second-order model gave better fitting parameters comparing to that of pseudo-first-order one. The thermodynamic parameters of the sorption processes revealed spontaneous and endothermic nature. High negativity of ΔG° values for the modified SiSb confirms the positive role of phosphoric acid impregnation in the sorption process. The break-through capacities of the studied ions were further calculated from a column investigation. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4WXHC0N-4&_user=6 [...]

Predicting emission characteristics of volatile organic compounds from wet surface coatings / Sacide Alsoy Altinkaya in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 586-593 Titre : Predicting emission characteristics of volatile organic compounds from wet surface coatings Type de document : texte imprimé Auteurs : Sacide Alsoy Altinkaya, Auteur Année de publication : 2010 Article en page(s) : pp. 586-593 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Mathematical  model  VOC  emission  Diffusion  Sorption  isotherm  Evaporation Index. décimale : 660 Résumé : A mathematical model is developed to describe the emission characteristics of VOCs from homogeneous wet coating materials deposited on impermeable substrates. The model considers mass transfer in the material and in air, boundary layer resistance and the change in the coating thickness with time due to emission of VOC. Key features of the model are incorporation of concentration dependent VOC diffusion coefficients predicted from a physical model and nonlinear equilibrium isotherm at the coating/air interface. The model is applied to predict emission characteristics of MMA from acrylic based surface coatings. In an attempt to investigate the influences of equilibrium isotherm type and diffusion formalism on the predictions, simulations are performed with either constant or concentration dependent diffusivities and linear or nonlinear equilibrium isotherms. The lowest MMA concentration in air is predicted by incorporating the concentration dependent diffusivity and nonlinear equilibrium isotherm. The results suggest that assuming the diffusivity of MMA constant or equilibrium isotherm linear may lead to wrong conclusions about the emission rates from wet coatings. The model is general, fully predictive and can be used to predict emission rates of different VOCs from different coating materials if diffusion and thermodynamic parameters are available. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4WY6K3W-3&_user=6 [...] [article] Predicting emission characteristics of volatile organic compounds from wet surface coatings [texte imprimé] / Sacide Alsoy Altinkaya, Auteur . - 2010 . - pp. 586-593. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 586-593 Mots-clés : Mathematical  model  VOC  emission  Diffusion  Sorption  isotherm  Evaporation Index. décimale : 660 Résumé : A mathematical model is developed to describe the emission characteristics of VOCs from homogeneous wet coating materials deposited on impermeable substrates. The model considers mass transfer in the material and in air, boundary layer resistance and the change in the coating thickness with time due to emission of VOC. Key features of the model are incorporation of concentration dependent VOC diffusion coefficients predicted from a physical model and nonlinear equilibrium isotherm at the coating/air interface. The model is applied to predict emission characteristics of MMA from acrylic based surface coatings. In an attempt to investigate the influences of equilibrium isotherm type and diffusion formalism on the predictions, simulations are performed with either constant or concentration dependent diffusivities and linear or nonlinear equilibrium isotherms. The lowest MMA concentration in air is predicted by incorporating the concentration dependent diffusivity and nonlinear equilibrium isotherm. The results suggest that assuming the diffusivity of MMA constant or equilibrium isotherm linear may lead to wrong conclusions about the emission rates from wet coatings. The model is general, fully predictive and can be used to predict emission rates of different VOCs from different coating materials if diffusion and thermodynamic parameters are available. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4WY6K3W-3&_user=6 [...]

Desulfurization of air at high and low H2S concentrations / Yehya Elsayed in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 594-602 Titre : Desulfurization of air at high and low H2S concentrations Type de document : texte imprimé Auteurs : Yehya Elsayed, Auteur ; Mykola Seredych, Auteur ; Andrew Dallas, Auteur Année de publication : 2010 Article en page(s) : pp. 594-602 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Activated  carbons  H2S  adsorption  Surface  chemistry  Pore  structure  Reactive  adsorption Index. décimale : 660 Résumé : Several commercially available coconut-based activated carbons were tested as adsorbents of hydrogen sulfide (H2S) at high and low H2S concentrations. These carbons were compared to an experimental coconut-based carbon modified by impregnation with strongly basic compounds and an oxidant. The breakthrough curves for H2S at 3000 ppm and 10 ppm were measured at room temperature. The effects of humidity and water content on H2S removal were investigated. The carbon samples were characterized before and after H2S adsorption using XRF, sorption of nitrogen, thermal analysis in combination with mass spectrometry (TGA–MS) and thermal desorption–gas chromatography–mass spectrometry (TD–GC–MS), along with pH measurements. These methods were used to track the activated carbon surface chemical changes upon H2S adsorption/reactive adsorption. The amount of H2S adsorbed on all activated carbons was found to be dependent on the amount of surface basic groups. TGA–MS and TD–GC–MS analysis revealed H2S is adsorbed via reactive adsorption mechanisms. Metal sulfates, elemental sulfur, carbon sulfide, oxides of sulfur and dihydrogen disulfide are the products of surface reactions. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X1SBK5-3&_user=6 [...] [article] Desulfurization of air at high and low H2S concentrations [texte imprimé] / Yehya Elsayed, Auteur ; Mykola Seredych, Auteur ; Andrew Dallas, Auteur . - 2010 . - pp. 594-602. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 594-602 Mots-clés : Activated  carbons  H2S  adsorption  Surface  chemistry  Pore  structure  Reactive  adsorption Index. décimale : 660 Résumé : Several commercially available coconut-based activated carbons were tested as adsorbents of hydrogen sulfide (H2S) at high and low H2S concentrations. These carbons were compared to an experimental coconut-based carbon modified by impregnation with strongly basic compounds and an oxidant. The breakthrough curves for H2S at 3000 ppm and 10 ppm were measured at room temperature. The effects of humidity and water content on H2S removal were investigated. The carbon samples were characterized before and after H2S adsorption using XRF, sorption of nitrogen, thermal analysis in combination with mass spectrometry (TGA–MS) and thermal desorption–gas chromatography–mass spectrometry (TD–GC–MS), along with pH measurements. These methods were used to track the activated carbon surface chemical changes upon H2S adsorption/reactive adsorption. The amount of H2S adsorbed on all activated carbons was found to be dependent on the amount of surface basic groups. TGA–MS and TD–GC–MS analysis revealed H2S is adsorbed via reactive adsorption mechanisms. Metal sulfates, elemental sulfur, carbon sulfide, oxides of sulfur and dihydrogen disulfide are the products of surface reactions. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X1SBK5-3&_user=6 [...]

Simulation of (bio)chemical processes with distributed parameters using Matlab / F. Logist in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 603-616 Titre : Simulation of (bio)chemical processes with distributed parameters using Matlab Type de document : texte imprimé Auteurs : F. Logist, Auteur ; P. Saucez, Auteur ; J. Van Impe, Auteur Année de publication : 2010 Article en page(s) : pp. 603-616 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Numerical  methods  Partial  differential  equations  Method  of  lines  Operator  splitting  Reverse  flow  reactor Index. décimale : 660 Résumé : Nowadays, simulations have become indispensable for the analysis and optimisation of (bio)chemical processes. However, as a lot of these processes are distributed in nature (i.e., the properties vary both in time and space), their simulation requires the solution of non-linear convection–reaction–diffusion partial differential equations (PDEs). Therefore, this paper compares different solution methods in a comprehensible way in order to provide practical guidelines. Moreover, to stimulate their usage in practice, all techniques have been implemented in Matlab®, and all test examples have been made available (www.matmol.org). This allows practitioners to rapidly evaluate different methods when setting-up their own process simulation code. Finally, a complex reverse flow reactor case illustrates how these methods can be successfully combined with optimisation approaches. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X378K2-2&_user=6 [...] [article] Simulation of (bio)chemical processes with distributed parameters using Matlab [texte imprimé] / F. Logist, Auteur ; P. Saucez, Auteur ; J. Van Impe, Auteur . - 2010 . - pp. 603-616. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 603-616 Mots-clés : Numerical  methods  Partial  differential  equations  Method  of  lines  Operator  splitting  Reverse  flow  reactor Index. décimale : 660 Résumé : Nowadays, simulations have become indispensable for the analysis and optimisation of (bio)chemical processes. However, as a lot of these processes are distributed in nature (i.e., the properties vary both in time and space), their simulation requires the solution of non-linear convection–reaction–diffusion partial differential equations (PDEs). Therefore, this paper compares different solution methods in a comprehensible way in order to provide practical guidelines. Moreover, to stimulate their usage in practice, all techniques have been implemented in Matlab®, and all test examples have been made available (www.matmol.org). This allows practitioners to rapidly evaluate different methods when setting-up their own process simulation code. Finally, a complex reverse flow reactor case illustrates how these methods can be successfully combined with optimisation approaches. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X378K2-2&_user=6 [...]

Response surface method applied to supercritical carbon dioxide extraction of Vetiveria zizanioides essential oil / Luu Thai Danh in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 617-626 Titre : Response surface method applied to supercritical carbon dioxide extraction of Vetiveria zizanioides essential oil Type de document : texte imprimé Auteurs : Luu Thai Danh, Auteur ; Raffaella Mammucari, Auteur ; Paul Truong, Auteur Année de publication : 2010 Article en page(s) : pp. 617-626 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Supercritical  carbon  dioxide  extraction  Vetiver  essential  oil  Response  surface  metho  Khuismol  Zizanoic  acid Index. décimale : 660 Résumé : Three operating parameters of supercritical carbon dioxide extraction (SCE) have been optimized by a response surface method using central composite design to obtain high yields of essential oil from roots of Vetiveria zizanioides. Analyses by multiple regression indicated that pressure has a major linear effect on oil yield, whilst temperature and time have a lesser impact. However, the effect of temperature in combination with pressure is significant. Overall, extraction yields increase with both pressure and temperature. The optimal SCE yield (1.38%) obtained at the operating conditions of 190 bar, 50 °C and 100 min was about four times higher than that achieved by hydro-distillation. In general, the quality of vetiver oil extracted by SCE is suitable for the food industry. In order for the SCE extracts to be acceptable in the perfumery industry, however, a high yield of vetiver oil would be required in association with high khusimol and low zizanoic acid contents. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X315MJ-1&_user=6 [...] [article] Response surface method applied to supercritical carbon dioxide extraction of Vetiveria zizanioides essential oil [texte imprimé] / Luu Thai Danh, Auteur ; Raffaella Mammucari, Auteur ; Paul Truong, Auteur . - 2010 . - pp. 617-626. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 617-626 Mots-clés : Supercritical  carbon  dioxide  extraction  Vetiver  essential  oil  Response  surface  metho  Khuismol  Zizanoic  acid Index. décimale : 660 Résumé : Three operating parameters of supercritical carbon dioxide extraction (SCE) have been optimized by a response surface method using central composite design to obtain high yields of essential oil from roots of Vetiveria zizanioides. Analyses by multiple regression indicated that pressure has a major linear effect on oil yield, whilst temperature and time have a lesser impact. However, the effect of temperature in combination with pressure is significant. Overall, extraction yields increase with both pressure and temperature. The optimal SCE yield (1.38%) obtained at the operating conditions of 190 bar, 50 °C and 100 min was about four times higher than that achieved by hydro-distillation. In general, the quality of vetiver oil extracted by SCE is suitable for the food industry. In order for the SCE extracts to be acceptable in the perfumery industry, however, a high yield of vetiver oil would be required in association with high khusimol and low zizanoic acid contents. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X315MJ-1&_user=6 [...]

Application of carbon adsorbents prepared from the Brazilian pine-fruit-shell for the removal of Procion Red MX 3B from aqueous solution—Kinetic, equilibrium, and thermodynamic studies / Tatiana Calvete in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 627-636 Titre : Application of carbon adsorbents prepared from the Brazilian pine-fruit-shell for the removal of Procion Red MX 3B from aqueous solution—Kinetic, equilibrium, and thermodynamic studies Type de document : texte imprimé Auteurs : Tatiana Calvete, Auteur ; Eder C. Lima, Auteur ; Natali F. Cardoso, Auteur Année de publication : 2010 Article en page(s) : pp. 627-636 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Adsorption  Brazilian  pine-fruit-shell  Activated  carbon  Procion  Red  MX  3B  dye  Simulated  dyehouse  effluent Index. décimale : 660 Résumé : Activated (AC-PW) and non-activated (C-PW) carbonaceous materials were prepared from the Brazilian pine-fruit-shell (Araucaria angustifolia) and tested as adsorbents for the removal of Procion Red MX 3B dye (PR-3B) from aqueous effluents. The activation process lead to increase in the specific surface area, average porous volume, and average porous diameter of the adsorbent AC-PW when compared to C-PW. The effects of shaking time, adsorbent dosage and pH on adsorption capacity were studied. PR-3B uptake was favorable at pHs ranging from 2.0 to 3.0 for C-PW and 2.0 to 7.0 for AC-PW. The contact time required to obtain the equilibrium using C-PW and AC-PW as adsorbents was 6 and 4 h at 298 K, respectively. The values of the function error (Ferror) of fractionary-order kinetic model was at least 15 times lower than the values obtained with pseudo-first-order, pseudo-second order and Elovich kinetic models, indicating that this kinetic model was better fitted to the experimental results. For equilibrium data the Ferror values of the Sips isotherm model were at least 4.0 lower than the values of Langmuir, Freundlich, and Redlich-Peterson isotherm models using C-PW and AC-PW as adsorbents. The enthalpy and entropy of adsorption of PR-3B were obtained from adsorption experiments ranging from 298 to 323 K. Simulated dyehouse effluents were used to check the applicability of the proposed carbons for effluent treatment. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X49YKT-1&_user=6 [...] [article] Application of carbon adsorbents prepared from the Brazilian pine-fruit-shell for the removal of Procion Red MX 3B from aqueous solution—Kinetic, equilibrium, and thermodynamic studies [texte imprimé] / Tatiana Calvete, Auteur ; Eder C. Lima, Auteur ; Natali F. Cardoso, Auteur . - 2010 . - pp. 627-636. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 627-636 Mots-clés : Adsorption  Brazilian  pine-fruit-shell  Activated  carbon  Procion  Red  MX  3B  dye  Simulated  dyehouse  effluent Index. décimale : 660 Résumé : Activated (AC-PW) and non-activated (C-PW) carbonaceous materials were prepared from the Brazilian pine-fruit-shell (Araucaria angustifolia) and tested as adsorbents for the removal of Procion Red MX 3B dye (PR-3B) from aqueous effluents. The activation process lead to increase in the specific surface area, average porous volume, and average porous diameter of the adsorbent AC-PW when compared to C-PW. The effects of shaking time, adsorbent dosage and pH on adsorption capacity were studied. PR-3B uptake was favorable at pHs ranging from 2.0 to 3.0 for C-PW and 2.0 to 7.0 for AC-PW. The contact time required to obtain the equilibrium using C-PW and AC-PW as adsorbents was 6 and 4 h at 298 K, respectively. The values of the function error (Ferror) of fractionary-order kinetic model was at least 15 times lower than the values obtained with pseudo-first-order, pseudo-second order and Elovich kinetic models, indicating that this kinetic model was better fitted to the experimental results. For equilibrium data the Ferror values of the Sips isotherm model were at least 4.0 lower than the values of Langmuir, Freundlich, and Redlich-Peterson isotherm models using C-PW and AC-PW as adsorbents. The enthalpy and entropy of adsorption of PR-3B were obtained from adsorption experiments ranging from 298 to 323 K. Simulated dyehouse effluents were used to check the applicability of the proposed carbons for effluent treatment. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X49YKT-1&_user=6 [...]

The role of iron on the degradation and mineralization of organic compounds using conventional Fenton and photo-Fenton processes / Daphne Hermosilla in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 637-646 Titre : The role of iron on the degradation and mineralization of organic compounds using conventional Fenton and photo-Fenton processes Type de document : texte imprimé Auteurs : Daphne Hermosilla, Auteur ; Manuel Cortijo, Auteur ; C.P. Huang, Auteur Année de publication : 2010 Article en page(s) : pp. 637-646 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Fenton  Photo-Fenton  Iron  complex  Phenol  Nitrophenol  Acetic  acid  Oxalic  acid  EDTA  Advanced  oxidation  processes Index. décimale : 660 Résumé : The role of iron on the degradation of different organic compounds, differing in their structure (aliphatic versus aromatic) and iron complex formation capacity, by conventional and photo-Fenton processes was investigated. Results show that these chemical characteristics can affect the degree of treatment in terms of COD and TOC removals. While aromatics exhibited a fast and great reduction in the COD by the conventional Fenton process, aliphatic compounds, apart from acetic acid, required the presence of UV light to enhance treatment results. EDTA and oxalic acid responded very positively to UV irradiation in both COD removal and mineralization, reaching the highest values showed by aromatics; and results depended on the intensity of the UV light applied. Phenol and 4-nitrophenol responded favourably to UV irradiation in terms of mineralization and slightly in COD removal. Reductions in the COD were almost total (95.99%), while only an 80% of reduction in the TOC was achieved, for the best photo-Fenton treatment of oxalic acid, phenol and nitrophenol. 60% COD and 40% TOC removals were achieved correspondingly in the case of EDTA. Acetic acid showed almost no mineralization and low COD removal (≈20%) when treated by a conventional Fenton process; and did not enhanced results when assisting the treatment with UV light. Photo-regeneration of ferrous ion and photo-decarboxylation of iron carboxylates are assessed in the framework of these results. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X49YKT-3&_user=6 [...] [article] The role of iron on the degradation and mineralization of organic compounds using conventional Fenton and photo-Fenton processes [texte imprimé] / Daphne Hermosilla, Auteur ; Manuel Cortijo, Auteur ; C.P. Huang, Auteur . - 2010 . - pp. 637-646. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 637-646 Mots-clés : Fenton  Photo-Fenton  Iron  complex  Phenol  Nitrophenol  Acetic  acid  Oxalic  acid  EDTA  Advanced  oxidation  processes Index. décimale : 660 Résumé : The role of iron on the degradation of different organic compounds, differing in their structure (aliphatic versus aromatic) and iron complex formation capacity, by conventional and photo-Fenton processes was investigated. Results show that these chemical characteristics can affect the degree of treatment in terms of COD and TOC removals. While aromatics exhibited a fast and great reduction in the COD by the conventional Fenton process, aliphatic compounds, apart from acetic acid, required the presence of UV light to enhance treatment results. EDTA and oxalic acid responded very positively to UV irradiation in both COD removal and mineralization, reaching the highest values showed by aromatics; and results depended on the intensity of the UV light applied. Phenol and 4-nitrophenol responded favourably to UV irradiation in terms of mineralization and slightly in COD removal. Reductions in the COD were almost total (95.99%), while only an 80% of reduction in the TOC was achieved, for the best photo-Fenton treatment of oxalic acid, phenol and nitrophenol. 60% COD and 40% TOC removals were achieved correspondingly in the case of EDTA. Acetic acid showed almost no mineralization and low COD removal (≈20%) when treated by a conventional Fenton process; and did not enhanced results when assisting the treatment with UV light. Photo-regeneration of ferrous ion and photo-decarboxylation of iron carboxylates are assessed in the framework of these results. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X49YKT-3&_user=6 [...]

Removal of lead copper chromium and cobalt ions onto granular activated carbon in batch and fixed-bed adsorbers / Abbas H. Sulaymon in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 647-653 Titre : Removal of lead copper chromium and cobalt ions onto granular activated carbon in batch and fixed-bed adsorbers Type de document : texte imprimé Auteurs : Abbas H. Sulaymon, Auteur ; Balasim A. Abid, Auteur ; Jenan A. Al-Najar, Auteur Année de publication : 2010 Article en page(s) : pp. 647-653 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Adsorption  Activated  carbon  Lead  Copper  Chromium  Cobalt Index. décimale : 660 Résumé : The adsorption of lead, copper, chromium and cobalt ions onto granular activated carbon (DARCO 20–40 mesh) in a single component system has been studied using fixed-bed adsorbers. A film-pore diffusion model has been utilized to predict the fixed-bed breakthrough curves for each of the four metal ions. This model considers both external and internal mass transfer resistances as well as axial dispersion with non-linear isotherm. The effects of flow rate, bed height and initial metal ion concentration on the breakthrough curves have been studied. The equilibrium isotherm data, the external mass transfer coefficient and pore diffusion coefficient were obtained from separate experiments in batch adsorber by fitting the experimental data with theoretical model. The pore diffusion coefficient was obtained using pore diffusion model for batch adsorber by matching between the experimental data and the model predicted data. The results show that the film-pore diffusion model used for fixed-bed adsorber provides a good description of adsorption process for Pb(II), Cu(II), Cr(III) and Co(II) onto activated carbon in fixed-bed adsorber. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X49YKT-4&_user=6 [...] [article] Removal of lead copper chromium and cobalt ions onto granular activated carbon in batch and fixed-bed adsorbers [texte imprimé] / Abbas H. Sulaymon, Auteur ; Balasim A. Abid, Auteur ; Jenan A. Al-Najar, Auteur . - 2010 . - pp. 647-653. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 647-653 Mots-clés : Adsorption  Activated  carbon  Lead  Copper  Chromium  Cobalt Index. décimale : 660 Résumé : The adsorption of lead, copper, chromium and cobalt ions onto granular activated carbon (DARCO 20–40 mesh) in a single component system has been studied using fixed-bed adsorbers. A film-pore diffusion model has been utilized to predict the fixed-bed breakthrough curves for each of the four metal ions. This model considers both external and internal mass transfer resistances as well as axial dispersion with non-linear isotherm. The effects of flow rate, bed height and initial metal ion concentration on the breakthrough curves have been studied. The equilibrium isotherm data, the external mass transfer coefficient and pore diffusion coefficient were obtained from separate experiments in batch adsorber by fitting the experimental data with theoretical model. The pore diffusion coefficient was obtained using pore diffusion model for batch adsorber by matching between the experimental data and the model predicted data. The results show that the film-pore diffusion model used for fixed-bed adsorber provides a good description of adsorption process for Pb(II), Cu(II), Cr(III) and Co(II) onto activated carbon in fixed-bed adsorber. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X49YKT-4&_user=6 [...]

Separation of p-chloronitrobenzene and o-chloronitrobenzene by selective adsorption using Silicalite-1 zeolite / Zhaobing Guo in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 654-659 Titre : Separation of p-chloronitrobenzene and o-chloronitrobenzene by selective adsorption using Silicalite-1 zeolite Type de document : texte imprimé Auteurs : Zhaobing Guo, Auteur ; Shourong Zheng, Auteur ; Zheng Zheng, Auteur Année de publication : 2010 Article en page(s) : pp. 654-659 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Chloronitrobenzene  Silicalite-1  zeolite  Adsorption  Separation Index. décimale : 660 Résumé : Silicalite-1 zeolite was used for selective adsorption and separation of p-chloronitrobenzene (p-CNB) and o-chloronitrobenzene (o-CNB). Maximum adsorption amounts of p-CNB in the zeolite are found to be approximately 4 molecules per unit cell (mol./u.c.), much higher than those of o-CNB. p-CNB molecules are considered to be located in zeolite intersections and channels. CNBs adsorption in Silicalite-1 zeolite follows pseudo-second-order kinetic model. Adsorption amounts and temperatures are the important parameters in affecting CNBs adsorption rate constants. Adsorption rate constants of p-CNB are higher than those of o-CNB in Silicalite-1 zeolite. p-CNB with a purity of 94.9% and o-CNB of 96.1% can be recovered with Silicalite-1 zeolite under an optimal separation condition investigated. Compared with Silicalite-1 zeolite, the presence of acid sites in zeolites is not only favorable for p-CNB selective adsorption from CNBs aqueous solution, but also improves the adsorption heat of p-CNB. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X49YKT-2&_user=6 [...] [article] Separation of p-chloronitrobenzene and o-chloronitrobenzene by selective adsorption using Silicalite-1 zeolite [texte imprimé] / Zhaobing Guo, Auteur ; Shourong Zheng, Auteur ; Zheng Zheng, Auteur . - 2010 . - pp. 654-659. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 654-659 Mots-clés : Chloronitrobenzene  Silicalite-1  zeolite  Adsorption  Separation Index. décimale : 660 Résumé : Silicalite-1 zeolite was used for selective adsorption and separation of p-chloronitrobenzene (p-CNB) and o-chloronitrobenzene (o-CNB). Maximum adsorption amounts of p-CNB in the zeolite are found to be approximately 4 molecules per unit cell (mol./u.c.), much higher than those of o-CNB. p-CNB molecules are considered to be located in zeolite intersections and channels. CNBs adsorption in Silicalite-1 zeolite follows pseudo-second-order kinetic model. Adsorption amounts and temperatures are the important parameters in affecting CNBs adsorption rate constants. Adsorption rate constants of p-CNB are higher than those of o-CNB in Silicalite-1 zeolite. p-CNB with a purity of 94.9% and o-CNB of 96.1% can be recovered with Silicalite-1 zeolite under an optimal separation condition investigated. Compared with Silicalite-1 zeolite, the presence of acid sites in zeolites is not only favorable for p-CNB selective adsorption from CNBs aqueous solution, but also improves the adsorption heat of p-CNB. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X49YKT-2&_user=6 [...]

Silver doping on TiO2 nanoparticles using a sacrificial acid and its photocatalytic performance under medium pressure mercury UV lamp / E. Pipelzadeh in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 660-665 Titre : Silver doping on TiO2 nanoparticles using a sacrificial acid and its photocatalytic performance under medium pressure mercury UV lamp Type de document : texte imprimé Auteurs : E. Pipelzadeh, Auteur ; A. A. Babaluo, Auteur ; M. Haghighi, Auteur Année de publication : 2010 Article en page(s) : pp. 660-665 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Nanocomposite  TiO2  Ag  Calcination  Photocatalytic  activity  UV  lamp Index. décimale : 660 Résumé : Titanium dioxide nanoparticles were modified using a sacrificial organic acid carrier at low pH values where the zeta potential of the TiO2 nanoparticles was found to be highly effective forming 0.05, 0.1, 0.5 wt.% Ag/TiO2 nanocomposites. The organic carrier was acting both as an Ag ion carrier and a hole scavenger enhancing the photodeposition of Ag atoms. The formed nanocomposites were calcined at 300 and 400 °C under controlled atmosphere and later examined for photocatalytic performance using a 125 medium pressure mercury lamp decomposing formic acid as an organic pollutant. Morphological, crystallographical and UV–vis spectroscopy analyses were used to characterize the synthesized nanocomposites. The studies have revealed that non-calcined 0.5 wt.% Ag/TiO2 nanocomposite has the best photocatalytic activity compared with other synthesized nanocomposites and that of the non-modified TiO2 (P25). Further calcination of the synthesized nanocomposites has shown to be effective in lower Ag concentrations where 0.1 wt.% Ag/TiO2 nanocomposite has the best photocatalytic activity at the 400 °C. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X49YKT-5&_user=6 [...] [article] Silver doping on TiO2 nanoparticles using a sacrificial acid and its photocatalytic performance under medium pressure mercury UV lamp [texte imprimé] / E. Pipelzadeh, Auteur ; A. A. Babaluo, Auteur ; M. Haghighi, Auteur . - 2010 . - pp. 660-665. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 660-665 Mots-clés : Nanocomposite  TiO2  Ag  Calcination  Photocatalytic  activity  UV  lamp Index. décimale : 660 Résumé : Titanium dioxide nanoparticles were modified using a sacrificial organic acid carrier at low pH values where the zeta potential of the TiO2 nanoparticles was found to be highly effective forming 0.05, 0.1, 0.5 wt.% Ag/TiO2 nanocomposites. The organic carrier was acting both as an Ag ion carrier and a hole scavenger enhancing the photodeposition of Ag atoms. The formed nanocomposites were calcined at 300 and 400 °C under controlled atmosphere and later examined for photocatalytic performance using a 125 medium pressure mercury lamp decomposing formic acid as an organic pollutant. Morphological, crystallographical and UV–vis spectroscopy analyses were used to characterize the synthesized nanocomposites. The studies have revealed that non-calcined 0.5 wt.% Ag/TiO2 nanocomposite has the best photocatalytic activity compared with other synthesized nanocomposites and that of the non-modified TiO2 (P25). Further calcination of the synthesized nanocomposites has shown to be effective in lower Ag concentrations where 0.1 wt.% Ag/TiO2 nanocomposite has the best photocatalytic activity at the 400 °C. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X49YKT-5&_user=6 [...]

Biosorption of hexavalent chromium from aqueous solutions by Catla catla scales / Kondapalli Srividya in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 666-673 Titre : Biosorption of hexavalent chromium from aqueous solutions by Catla catla scales : equilibrium and kinetics studies Type de document : texte imprimé Auteurs : Kondapalli Srividya, Auteur ; Kaustubha Mohanty, Auteur Année de publication : 2010 Article en page(s) : pp. 666-673 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Biosorption  Chromium  Heavy  metal  Kinetics  Wastewater  treatment Index. décimale : 660 Résumé : In this work the potential of Catla catla scales to remove Cr(VI) ions from aqueous solutions was investigated as a function of time, initial Cr(VI) concentration, initial pH, biomass dose and agitation speed. Optimum biosorption conditions were found to be pH 1.0, 0.05 g L−1 biomass dosage, 200 rpm agitation speed and 180 min equilibrium time. The fitness of biosorption equilibrium data for Freundlich, Langmuir and Dubinin–Radushkevich isotherm models were tested. It was found that Freundlich model was better suitable for biosorption of Cr(VI) ions onto C. catla biomass. Three kinetic models viz. the Lagergren first-order and pseudo-second-order and intra-particle diffusion model were used to analyze the biosorption data and the results suggested that the pseudo-second-order model represented the best correlation. FTIR spectrum analysis revealed that O–H, N–H and C–O groups were the leading Cr(VI) binding groups. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X49YKT-6&_user=6 [...] [article] Biosorption of hexavalent chromium from aqueous solutions by Catla catla scales : equilibrium and kinetics studies [texte imprimé] / Kondapalli Srividya, Auteur ; Kaustubha Mohanty, Auteur . - 2010 . - pp. 666-673. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 666-673 Mots-clés : Biosorption  Chromium  Heavy  metal  Kinetics  Wastewater  treatment Index. décimale : 660 Résumé : In this work the potential of Catla catla scales to remove Cr(VI) ions from aqueous solutions was investigated as a function of time, initial Cr(VI) concentration, initial pH, biomass dose and agitation speed. Optimum biosorption conditions were found to be pH 1.0, 0.05 g L−1 biomass dosage, 200 rpm agitation speed and 180 min equilibrium time. The fitness of biosorption equilibrium data for Freundlich, Langmuir and Dubinin–Radushkevich isotherm models were tested. It was found that Freundlich model was better suitable for biosorption of Cr(VI) ions onto C. catla biomass. Three kinetic models viz. the Lagergren first-order and pseudo-second-order and intra-particle diffusion model were used to analyze the biosorption data and the results suggested that the pseudo-second-order model represented the best correlation. FTIR spectrum analysis revealed that O–H, N–H and C–O groups were the leading Cr(VI) binding groups. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X49YKT-6&_user=6 [...]

Kinetic study of adsorption and photo-decolorization of Reactive Red 198 on TiO2 surface / S. Dutta in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 674-679 Titre : Kinetic study of adsorption and photo-decolorization of Reactive Red 198 on TiO2 surface Type de document : texte imprimé Auteurs : S. Dutta, Auteur ; S.A. Parsons, Auteur ; C. Bhattacharjee, Auteur Année de publication : 2010 Article en page(s) : pp. 674-679 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Adsorption  Advanced  oxidation  process  Catalyst  regeneration  Reactive  Red  198  TiO2-photocatalysis  Catalyst  activity Index. décimale : 660 Résumé : Recycling and reuse of wastewater after purification will reduce the environmental pollution as well as fulfill the increasing demand of water. Adsorption-based water treatment process is very popular for dye-house wastewater treatment. The present study deals with treatment of wastewater contaminated by reactive dye. TiO2 is used as adsorbent and the spent adsorbent has been regenerated by Advanced Oxidation Process (AOP), without using any other chemicals. TiO2 adsorbs dye molecules and then those dye molecules have been oxidized via a photocatalytic reaction in presence of UV irradiation. Kinetics of dye adsorption and photocatalytic oxidation reaction has been developed in this study. Photocatalyst adsorbent (TiO2) has been reused several times after regeneration. The activity of catalyst decreases after each cycle; due to poisoning cause by intermediate by-products. Kinetic of this catalyst deactivation has been incorporated with L–H model to develop the photocatalytic reaction kinetic model. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X4RWW8-1&_user=6 [...] [article] Kinetic study of adsorption and photo-decolorization of Reactive Red 198 on TiO2 surface [texte imprimé] / S. Dutta, Auteur ; S.A. Parsons, Auteur ; C. Bhattacharjee, Auteur . - 2010 . - pp. 674-679. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 674-679 Mots-clés : Adsorption  Advanced  oxidation  process  Catalyst  regeneration  Reactive  Red  198  TiO2-photocatalysis  Catalyst  activity Index. décimale : 660 Résumé : Recycling and reuse of wastewater after purification will reduce the environmental pollution as well as fulfill the increasing demand of water. Adsorption-based water treatment process is very popular for dye-house wastewater treatment. The present study deals with treatment of wastewater contaminated by reactive dye. TiO2 is used as adsorbent and the spent adsorbent has been regenerated by Advanced Oxidation Process (AOP), without using any other chemicals. TiO2 adsorbs dye molecules and then those dye molecules have been oxidized via a photocatalytic reaction in presence of UV irradiation. Kinetics of dye adsorption and photocatalytic oxidation reaction has been developed in this study. Photocatalyst adsorbent (TiO2) has been reused several times after regeneration. The activity of catalyst decreases after each cycle; due to poisoning cause by intermediate by-products. Kinetic of this catalyst deactivation has been incorporated with L–H model to develop the photocatalytic reaction kinetic model. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X4RWW8-1&_user=6 [...]

Fenton oxidative decolorization of the azo dye Direct Blue 15 in aqueous solution / Jian-Hui Sun in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 680-683 Titre : Fenton oxidative decolorization of the azo dye Direct Blue 15 in aqueous solution Type de document : texte imprimé Auteurs : Jian-Hui Sun, Auteur ; Shao-Hui Shi, Auteur ; Yi-Fan Lee, Auteur Année de publication : 2010 Article en page(s) : pp. 680-683 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Azo  dye  Direct  Blue  15  Decolorization  Fenton  process  AOPs Index. décimale : 660 Résumé : In this paper, the application of Fenton oxidation process for the decolorization of an azo dye Direct Blue 15 (DB15) in aqueous solution was investigated. The effect of initial pH, dosage of H2O2, H2O2/Fe2+ and H2O2/dye ratios and the reaction temperature on the decolorization efficiency and kinetic of the DB15 were studied, the operating parameters were preferred by changing one factor at one time while the other parameters were kept constant. The optimal conditions for the decolorization of DB15 were determined as pH = 4.0, [H2O2] = 2.8 × 10−3 mol/L, H2O2/Fe2+ ratio = 100:1, H2O2/dye ratio = 60:1 and temperature = 30 °C. Under the optimal conditions, 4.7 × 10−5 mol/L of the DB15 aqueous solution can be completely decolorized by Fenton oxidation within 50-min reaction time and the decolorization kinetic rate constant k was determined as 0.1694 min−1. Additionally increasing the reaction temperature from 20 to 40 °C showed a positive effect on the decolorization efficiency of DB15. The present study can provide guidance to relational industry operators and planners to effectively treat the DB15 contaminated wastewater by Fenton oxidation process. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X4RWW8-4&_user=6 [...] [article] Fenton oxidative decolorization of the azo dye Direct Blue 15 in aqueous solution [texte imprimé] / Jian-Hui Sun, Auteur ; Shao-Hui Shi, Auteur ; Yi-Fan Lee, Auteur . - 2010 . - pp. 680-683. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 680-683 Mots-clés : Azo  dye  Direct  Blue  15  Decolorization  Fenton  process  AOPs Index. décimale : 660 Résumé : In this paper, the application of Fenton oxidation process for the decolorization of an azo dye Direct Blue 15 (DB15) in aqueous solution was investigated. The effect of initial pH, dosage of H2O2, H2O2/Fe2+ and H2O2/dye ratios and the reaction temperature on the decolorization efficiency and kinetic of the DB15 were studied, the operating parameters were preferred by changing one factor at one time while the other parameters were kept constant. The optimal conditions for the decolorization of DB15 were determined as pH = 4.0, [H2O2] = 2.8 × 10−3 mol/L, H2O2/Fe2+ ratio = 100:1, H2O2/dye ratio = 60:1 and temperature = 30 °C. Under the optimal conditions, 4.7 × 10−5 mol/L of the DB15 aqueous solution can be completely decolorized by Fenton oxidation within 50-min reaction time and the decolorization kinetic rate constant k was determined as 0.1694 min−1. Additionally increasing the reaction temperature from 20 to 40 °C showed a positive effect on the decolorization efficiency of DB15. The present study can provide guidance to relational industry operators and planners to effectively treat the DB15 contaminated wastewater by Fenton oxidation process. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X4RWW8-4&_user=6 [...]

Degradation of reactive red 194 and reactive yellow 145 azo dyes by O3 and H2O2/UV-C processes / Sermin Gül in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 684-690 Titre : Degradation of reactive red 194 and reactive yellow 145 azo dyes by O3 and H2O2/UV-C processes Type de document : texte imprimé Auteurs : Sermin Gül, Auteur ; Ozlem Ozcan-Yildirim, Auteur Année de publication : 2010 Article en page(s) : pp. 684-690 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Ozonation  Hydrogen  peroxide/UV-C  Reactive  Red  194  Reactive  Yellow  145  Decolorization  Dearomatization Index. décimale : 660 Résumé : Reactive Red 194 (RR194), Reactive Yellow 145 (RY145) azo dyes and synthetic textile dye-bath effluent were treated with O3 and H2O2/UV-C processes. The operating parameters such as dye concentration, hydrogen peroxide concentration and pH values were evaluated to find the optimum conditions for the H2O2/UV-C processes. It was observed that while H2O2/UV-C process was more pH dependent in decolorization and dearomatization reactions, ozonation was less selective and more effective in both decolorization and dearomatization reactions. Results indicated that the decolorization and dearomatization rate of each dye are well defined by pseudo-first order reaction kinetics. In general, decolorization reactions were faster than dearomatization reactions in both systems, though ozonation had faster reaction rates in both decolorization and dearomatization compared to the corresponding reaction rates taking place during the application of the H2O2/UV-C process. According to decolorization efficiency it can be inferred that effect of OH radical scavengers (e.g. CO32−, Cl−) present in the synthetic dye-bath as well as radical formation promoter (e.g. OH−) was probably hidden due to complexity of the synthetic dye-bath matrix. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X4RWW8-3&_user=6 [...] [article] Degradation of reactive red 194 and reactive yellow 145 azo dyes by O3 and H2O2/UV-C processes [texte imprimé] / Sermin Gül, Auteur ; Ozlem Ozcan-Yildirim, Auteur . - 2010 . - pp. 684-690. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 684-690 Mots-clés : Ozonation  Hydrogen  peroxide/UV-C  Reactive  Red  194  Reactive  Yellow  145  Decolorization  Dearomatization Index. décimale : 660 Résumé : Reactive Red 194 (RR194), Reactive Yellow 145 (RY145) azo dyes and synthetic textile dye-bath effluent were treated with O3 and H2O2/UV-C processes. The operating parameters such as dye concentration, hydrogen peroxide concentration and pH values were evaluated to find the optimum conditions for the H2O2/UV-C processes. It was observed that while H2O2/UV-C process was more pH dependent in decolorization and dearomatization reactions, ozonation was less selective and more effective in both decolorization and dearomatization reactions. Results indicated that the decolorization and dearomatization rate of each dye are well defined by pseudo-first order reaction kinetics. In general, decolorization reactions were faster than dearomatization reactions in both systems, though ozonation had faster reaction rates in both decolorization and dearomatization compared to the corresponding reaction rates taking place during the application of the H2O2/UV-C process. According to decolorization efficiency it can be inferred that effect of OH radical scavengers (e.g. CO32−, Cl−) present in the synthetic dye-bath as well as radical formation promoter (e.g. OH−) was probably hidden due to complexity of the synthetic dye-bath matrix. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X4RWW8-3&_user=6 [...]

Atrazine degradation by in situ electrochemically generated ozone / Ysrael Marrero Vera in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 691-697 Titre : Atrazine degradation by in situ electrochemically generated ozone Type de document : texte imprimé Auteurs : Ysrael Marrero Vera, Auteur ; Roberto José De Carvalho, Auteur ; Mauricio Leonardo Torem, Auteur Année de publication : 2010 Article en page(s) : pp. 691-697 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Groundwater  Remediation  PbO2  electrode  Electrochemistry  Ozone  Atrazine Index. décimale : 660 Résumé : A study on the evaluation of the effectiveness of atrazine degradation by in situ electrochemically generated ozone was conducted. Ti/β-PbO2 electrodes were used as anodes for the ozone production. The rate of ozone generation, the ozone saturation concentration and the atrazine degradation rate increased with increasing current density. The maximum rate was close to 40 mg h−1, the dissolved ozone concentration was 1.6 mg L−1 for a current density of 1.5 kA m−2 and the electrochemical efficiency was around 6%. The degradation data followed a pseudo first-order kinetic. The values of the rate constants were 6.2 × 10−3, 8.8 × 10−3, and 1.21 × 10−2 min−1 for 0.5, 1.0, and 1.5 kA m−2, respectively. The degradation took place by the combined oxidation with O3 and radical dotOH generated at the Ti/β-PbO2 anode surface and by ozone decomposition. The rate was electrochemically controlled up to approximately 90% of degradation and by mass transfer thereafter. The degradation mechanism was comprised mainly by dealkylation followed by a slow dechlorination of the atrazine molecule. Continuous atrazine degradation tests were conducted in a column containing a porous medium with the purpose of determining whether the in situ electrochemical production of the oxidants radical dotOH/O3 is effective at reducing the atrazine concentration in the transported flux across the bed. The work demonstrates the potential applicability of the continuous system for in situ atrazine degradation in underground waters, and provides a basis for the future development of this technology. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X5JRBR-1&_user=6 [...] [article] Atrazine degradation by in situ electrochemically generated ozone [texte imprimé] / Ysrael Marrero Vera, Auteur ; Roberto José De Carvalho, Auteur ; Mauricio Leonardo Torem, Auteur . - 2010 . - pp. 691-697. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 691-697 Mots-clés : Groundwater  Remediation  PbO2  electrode  Electrochemistry  Ozone  Atrazine Index. décimale : 660 Résumé : A study on the evaluation of the effectiveness of atrazine degradation by in situ electrochemically generated ozone was conducted. Ti/β-PbO2 electrodes were used as anodes for the ozone production. The rate of ozone generation, the ozone saturation concentration and the atrazine degradation rate increased with increasing current density. The maximum rate was close to 40 mg h−1, the dissolved ozone concentration was 1.6 mg L−1 for a current density of 1.5 kA m−2 and the electrochemical efficiency was around 6%. The degradation data followed a pseudo first-order kinetic. The values of the rate constants were 6.2 × 10−3, 8.8 × 10−3, and 1.21 × 10−2 min−1 for 0.5, 1.0, and 1.5 kA m−2, respectively. The degradation took place by the combined oxidation with O3 and radical dotOH generated at the Ti/β-PbO2 anode surface and by ozone decomposition. The rate was electrochemically controlled up to approximately 90% of degradation and by mass transfer thereafter. The degradation mechanism was comprised mainly by dealkylation followed by a slow dechlorination of the atrazine molecule. Continuous atrazine degradation tests were conducted in a column containing a porous medium with the purpose of determining whether the in situ electrochemical production of the oxidants radical dotOH/O3 is effective at reducing the atrazine concentration in the transported flux across the bed. The work demonstrates the potential applicability of the continuous system for in situ atrazine degradation in underground waters, and provides a basis for the future development of this technology. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X5JRBR-1&_user=6 [...]

Assessment of the leaching characteristics of incineration ashes in cement matrix / R.O. Abdel Rahman in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 698-708 Titre : Assessment of the leaching characteristics of incineration ashes in cement matrix Type de document : texte imprimé Auteurs : R.O. Abdel Rahman, Auteur ; A.A. Zaki, Auteur Année de publication : 2010 Article en page(s) : pp. 698-708 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Radioactive  waste  Incineration  Leaching  mechanisms  Mathematical  models Index. décimale : 660 Résumé : In this work, the effort is directed to assess the feasibility of immobilizing the ash produced from the incineration of solid radioactive wastes. Within this context, the ash was characterized to determine its chemical composition and physical properties. Immobilized cement-ash matrices have been prepared to investigate the influence of waste to cement ratio. To characterize the extent of the solidification process of the immobilized waste matrices, the mechanical strength test was conducted. The standard mass transfer leach test has been employed to test the extent of 137Cs and 60Co stabilization. Non-linear fitting of the experimental leach data to different mathematical models was conducted to evaluate the mechanisms those instigate the leaching phenomena and the leaching parameters were determined. The controlling leaching mechanism and leachability indices were calculated for the studied waste matrices. The results indicated that 137Cs leaching is resulted from first-order reaction between the surface of the waste matrix and the leaching solution followed by diffusion through the studied matrices. The leaching of 60Co was found to be as result of four subsequent mechanisms that include release of loosely bound 60Co followed by first-order reaction the diffusion and finally dissolution. It was found that the studied immobilized waste matrices have acceptable mechanical performance. The values of the leachability indices indicate that the performance of the studied matrices in 137Cs stabilization is not acceptable. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X5JRBR-2&_user=6 [...] [article] Assessment of the leaching characteristics of incineration ashes in cement matrix [texte imprimé] / R.O. Abdel Rahman, Auteur ; A.A. Zaki, Auteur . - 2010 . - pp. 698-708. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 698-708 Mots-clés : Radioactive  waste  Incineration  Leaching  mechanisms  Mathematical  models Index. décimale : 660 Résumé : In this work, the effort is directed to assess the feasibility of immobilizing the ash produced from the incineration of solid radioactive wastes. Within this context, the ash was characterized to determine its chemical composition and physical properties. Immobilized cement-ash matrices have been prepared to investigate the influence of waste to cement ratio. To characterize the extent of the solidification process of the immobilized waste matrices, the mechanical strength test was conducted. The standard mass transfer leach test has been employed to test the extent of 137Cs and 60Co stabilization. Non-linear fitting of the experimental leach data to different mathematical models was conducted to evaluate the mechanisms those instigate the leaching phenomena and the leaching parameters were determined. The controlling leaching mechanism and leachability indices were calculated for the studied waste matrices. The results indicated that 137Cs leaching is resulted from first-order reaction between the surface of the waste matrix and the leaching solution followed by diffusion through the studied matrices. The leaching of 60Co was found to be as result of four subsequent mechanisms that include release of loosely bound 60Co followed by first-order reaction the diffusion and finally dissolution. It was found that the studied immobilized waste matrices have acceptable mechanical performance. The values of the leachability indices indicate that the performance of the studied matrices in 137Cs stabilization is not acceptable. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X5JRBR-2&_user=6 [...]

Characterization of membrane foulants in an anaerobic non-woven fabric membrane bioreactor for municipal wastewater treatment / Ying An in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 709-715 Titre : Characterization of membrane foulants in an anaerobic non-woven fabric membrane bioreactor for municipal wastewater treatment Type de document : texte imprimé Auteurs : Ying An, Auteur ; Zhiwei Wang, Auteur ; Zhichao Wu, Auteur Année de publication : 2010 Article en page(s) : pp. 709-715 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Anaerobic  membrane  bioreactor  (AnMBR)  Membrane  fouling  Non-woven  filter  material  Wastewater  treatment Index. décimale : 660 Résumé : Membrane foulants were systematically characterized in an anaerobic membrane bioreactor (AnMBR), in which non-woven fabric was used as the membrane material. In this study, three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy, gel filtration chromatography (GFC), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and energy-diffusive X-ray (EDX) analyzer were used to analyze the membrane foulants. The results indicated that the organic substances with fluorescence characteristics in the extracellular polymeric substances (EPS) extracted from the membrane foulants were identified as proteins and visible humic acid-like substances by EEM technology. The GFC analysis exhibited that the EPS had much broader distributions of molecular weight (MW) and a larger weight-average molecular weight (Mw) compared with the influent wastewater and the effluent. Proteins and clay materials were also identified in the fouling layer by the FT-IR analysis. The examination by EDX demonstrated that Mg, Al, Ca, Si, and Fe were the major inorganic elements in the fouling cake. Furthermore, the results suggested that bridging between deposited biopolymers and inorganic compounds could enhance the compactness of fouling layer. During the operation of AnMBR, the protein-like and visible humic acid-like substances, which were main components of the organic matters with fluorescence characteristics in the influent, were partly removed. And the large MW organics (>4000 Da) in the influent were partly metabolized into low MW organics by microorganisms combined with the separation function of the cake layer and the membrane pores. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X5JRBR-3&_user=6 [...] [article] Characterization of membrane foulants in an anaerobic non-woven fabric membrane bioreactor for municipal wastewater treatment [texte imprimé] / Ying An, Auteur ; Zhiwei Wang, Auteur ; Zhichao Wu, Auteur . - 2010 . - pp. 709-715. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 709-715 Mots-clés : Anaerobic  membrane  bioreactor  (AnMBR)  Membrane  fouling  Non-woven  filter  material  Wastewater  treatment Index. décimale : 660 Résumé : Membrane foulants were systematically characterized in an anaerobic membrane bioreactor (AnMBR), in which non-woven fabric was used as the membrane material. In this study, three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy, gel filtration chromatography (GFC), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and energy-diffusive X-ray (EDX) analyzer were used to analyze the membrane foulants. The results indicated that the organic substances with fluorescence characteristics in the extracellular polymeric substances (EPS) extracted from the membrane foulants were identified as proteins and visible humic acid-like substances by EEM technology. The GFC analysis exhibited that the EPS had much broader distributions of molecular weight (MW) and a larger weight-average molecular weight (Mw) compared with the influent wastewater and the effluent. Proteins and clay materials were also identified in the fouling layer by the FT-IR analysis. The examination by EDX demonstrated that Mg, Al, Ca, Si, and Fe were the major inorganic elements in the fouling cake. Furthermore, the results suggested that bridging between deposited biopolymers and inorganic compounds could enhance the compactness of fouling layer. During the operation of AnMBR, the protein-like and visible humic acid-like substances, which were main components of the organic matters with fluorescence characteristics in the influent, were partly removed. And the large MW organics (>4000 Da) in the influent were partly metabolized into low MW organics by microorganisms combined with the separation function of the cake layer and the membrane pores. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X5JRBR-3&_user=6 [...]

Predicting Fe3+ dose for As(V) removal at pHs and temperatures commonly encountered in natural waters / Manassis G. Mitrakas in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 716-721 Titre : Predicting Fe3+ dose for As(V) removal at pHs and temperatures commonly encountered in natural waters Type de document : texte imprimé Auteurs : Manassis G. Mitrakas, Auteur ; Paul Chr. Panteliadis, Auteur ; Vissarion Z. Keramidas, Auteur Année de publication : 2010 Article en page(s) : pp. 716-721 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Natural  water  Arsenic  removal  Ferric  coagulant Index. décimale : 660 Résumé : Equations describing quantitatively the relation between Fe3+ dose and residual arsenic concentration, Ce, at pH values ranging between 6 and 8 and various initial arsenic concentrations, Co, were established using a natural water spiked with As(V). These equations were used to calculate the specific arsenic removal, q, in μg As removed per mg Fe3+ added. In turn, reliable equations relating q and Ce in the range between 2 and 20 μg As/L were derived. The latter equations predicted Fe3+ dose, necessary to achieve any selected Ce, when the water's Co and pH were known, with a satisfactory degree of accuracy (relative standard deviation less than 15%). In addition, comparison of As(V) removal data from full scale water treatment plants to those predicted by the empirical equations presented in this work, corroborated the fact that these equations can serve as a reliable guide for the prediction of Fe3+ dose necessary to remove As(V) from drinking water. The process of arsenic removal by using Fe3+ as a coagulant was found to be exothermic in character and Ce showed an increase by a factor of about 1.5 for each 10 °C increase in temperature. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X7GMP2-1&_user=6 [...] [article] Predicting Fe3+ dose for As(V) removal at pHs and temperatures commonly encountered in natural waters [texte imprimé] / Manassis G. Mitrakas, Auteur ; Paul Chr. Panteliadis, Auteur ; Vissarion Z. Keramidas, Auteur . - 2010 . - pp. 716-721. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 716-721 Mots-clés : Natural  water  Arsenic  removal  Ferric  coagulant Index. décimale : 660 Résumé : Equations describing quantitatively the relation between Fe3+ dose and residual arsenic concentration, Ce, at pH values ranging between 6 and 8 and various initial arsenic concentrations, Co, were established using a natural water spiked with As(V). These equations were used to calculate the specific arsenic removal, q, in μg As removed per mg Fe3+ added. In turn, reliable equations relating q and Ce in the range between 2 and 20 μg As/L were derived. The latter equations predicted Fe3+ dose, necessary to achieve any selected Ce, when the water's Co and pH were known, with a satisfactory degree of accuracy (relative standard deviation less than 15%). In addition, comparison of As(V) removal data from full scale water treatment plants to those predicted by the empirical equations presented in this work, corroborated the fact that these equations can serve as a reliable guide for the prediction of Fe3+ dose necessary to remove As(V) from drinking water. The process of arsenic removal by using Fe3+ as a coagulant was found to be exothermic in character and Ce showed an increase by a factor of about 1.5 for each 10 °C increase in temperature. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X7GMP2-1&_user=6 [...]

Adsorption of p-nitroaniline by phenolic hydroxyl groups modified hyper-cross-linked polymeric adsorbent and XAD-4 / Jianhan Huang in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 722-727 Titre : Adsorption of p-nitroaniline by phenolic hydroxyl groups modified hyper-cross-linked polymeric adsorbent and XAD-4 : a comparative study Type de document : texte imprimé Auteurs : Jianhan Huang, Auteur ; Xianguang Wang, Auteur ; Kelong Huang, Auteur Année de publication : 2010 Article en page(s) : pp. 722-727 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Polymeric  adsorbent  Adsorption  p-Nitroaniline  XAD-4 Index. décimale : 660 Résumé : Phenolic hydroxyl groups modified hyper-cross-linked polymeric adsorbent HJ-02 was prepared and it was applied to remove p-nitroaniline in aqueous solution as compared with Amberlite XAD-4. The results indicated that the adsorption at the solution pH of 3.7–7.8 was efficient for HJ-02 resin while that at the solution pH higher than 4.1 was favorable for XAD-4. The ionic strength affected the adsorption slightly and NaCl at a low concentration (<10%) had a positive effect. The adsorption kinetic curves obeyed the pseudo-second-order rate equation and HJ-02 resin had lower rate constant than XAD-4. The adsorption isotherms could be fitted by Langmuir isotherm and the adsorption capacity onto HJ-02 resin was much larger than that onto XAD-4. The adsorption enthalpy, adsorption free energy, and adsorption entropy onto HJ-02 resin were a little more negative than those onto XAD-4. Analysis of the adsorption mechanism suggested that the phenolic hydroxyl groups uploaded on HJ-02 resin and the predominant mesopores (2–5 nm) were the main reasons for its much larger adsorption capacity. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X7GMP2-2&_user=6 [...] [article] Adsorption of p-nitroaniline by phenolic hydroxyl groups modified hyper-cross-linked polymeric adsorbent and XAD-4 : a comparative study [texte imprimé] / Jianhan Huang, Auteur ; Xianguang Wang, Auteur ; Kelong Huang, Auteur . - 2010 . - pp. 722-727. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 722-727 Mots-clés : Polymeric  adsorbent  Adsorption  p-Nitroaniline  XAD-4 Index. décimale : 660 Résumé : Phenolic hydroxyl groups modified hyper-cross-linked polymeric adsorbent HJ-02 was prepared and it was applied to remove p-nitroaniline in aqueous solution as compared with Amberlite XAD-4. The results indicated that the adsorption at the solution pH of 3.7–7.8 was efficient for HJ-02 resin while that at the solution pH higher than 4.1 was favorable for XAD-4. The ionic strength affected the adsorption slightly and NaCl at a low concentration (<10%) had a positive effect. The adsorption kinetic curves obeyed the pseudo-second-order rate equation and HJ-02 resin had lower rate constant than XAD-4. The adsorption isotherms could be fitted by Langmuir isotherm and the adsorption capacity onto HJ-02 resin was much larger than that onto XAD-4. The adsorption enthalpy, adsorption free energy, and adsorption entropy onto HJ-02 resin were a little more negative than those onto XAD-4. Analysis of the adsorption mechanism suggested that the phenolic hydroxyl groups uploaded on HJ-02 resin and the predominant mesopores (2–5 nm) were the main reasons for its much larger adsorption capacity. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X7GMP2-2&_user=6 [...]

Effect of pH on cadmium (II) removal from aqueous solution using titanosilicate ETS-4 / Lidiana D. Barreira in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 728-735 Titre : Effect of pH on cadmium (II) removal from aqueous solution using titanosilicate ETS-4 Type de document : texte imprimé Auteurs : Lidiana D. Barreira, Auteur ; Patrícia F. Lito, Auteur ; Bruno M. Antunes, Auteur Année de publication : 2010 Article en page(s) : pp. 728-735 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Cadmium  ETS-4  Ion  exchange  Batch  experiments  Nernst–Planck Index. décimale : 660 Résumé : Cadmium is one of the most toxic contaminants of superficial waters, whose effects are particularly harmful to human health. In 20 years the European Union will impose total elimination of cadmium from industrial discharges. Such facts induce researchers to develop fine separation processes for cadmium removal, especially at the tertiary treatment level. In this work, we studied the applicability of the microporous titanosilicate ETS-4 (Engelhard Titanium Silicates No. 4) to uptake Cd2+ from aqueous solution, in order to evaluate its potential as ion exchanger material. The effect of pH was investigated by performing batch stirred tank experiments. The results obtained shown that Cd2+ removal increases up till pH 6, which is a very important conclusion since this value is commonly found in effluents and other wastewaters. The equilibrium data at pH 6 were accurately represented by the Langmuir–Freundlich isotherm under the experimental conditions studied (average absolute deviation, AAD = 1.67%). The amount of Cd2+ removed by ETS-4 at pH 6 clearly surmount results found in literature for the same titanosilicate at pH 4 and for different materials. The kinetic of Cd2+ uptake by ETS-4 was analyzed using a Nernst–Planck based model. The absolute average deviation found point out the reasonable data representation accomplished by Nernst–Planck: AAD = 17.2%. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X7GMP2-3&_user=6 [...] [article] Effect of pH on cadmium (II) removal from aqueous solution using titanosilicate ETS-4 [texte imprimé] / Lidiana D. Barreira, Auteur ; Patrícia F. Lito, Auteur ; Bruno M. Antunes, Auteur . - 2010 . - pp. 728-735. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 728-735 Mots-clés : Cadmium  ETS-4  Ion  exchange  Batch  experiments  Nernst–Planck Index. décimale : 660 Résumé : Cadmium is one of the most toxic contaminants of superficial waters, whose effects are particularly harmful to human health. In 20 years the European Union will impose total elimination of cadmium from industrial discharges. Such facts induce researchers to develop fine separation processes for cadmium removal, especially at the tertiary treatment level. In this work, we studied the applicability of the microporous titanosilicate ETS-4 (Engelhard Titanium Silicates No. 4) to uptake Cd2+ from aqueous solution, in order to evaluate its potential as ion exchanger material. The effect of pH was investigated by performing batch stirred tank experiments. The results obtained shown that Cd2+ removal increases up till pH 6, which is a very important conclusion since this value is commonly found in effluents and other wastewaters. The equilibrium data at pH 6 were accurately represented by the Langmuir–Freundlich isotherm under the experimental conditions studied (average absolute deviation, AAD = 1.67%). The amount of Cd2+ removed by ETS-4 at pH 6 clearly surmount results found in literature for the same titanosilicate at pH 4 and for different materials. The kinetic of Cd2+ uptake by ETS-4 was analyzed using a Nernst–Planck based model. The absolute average deviation found point out the reasonable data representation accomplished by Nernst–Planck: AAD = 17.2%. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X7GMP2-3&_user=6 [...]

Pervaporation dehydration of C2–C4 alcohols by 6FDA-ODA-NDA/Ultem® dual-layer hollow fiber membranes with enhanced separation performance and swelling resistance / Natalia Widjojo in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 736-743 Titre : Pervaporation dehydration of C2–C4 alcohols by 6FDA-ODA-NDA/Ultem® dual-layer hollow fiber membranes with enhanced separation performance and swelling resistance Type de document : texte imprimé Auteurs : Natalia Widjojo, Auteur ; Tai-Shung Chung, Auteur Année de publication : 2010 Article en page(s) : pp. 736-743 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Dual-layer  hollow  fiber  membranes  Pervaporation  Alcohol  dehydration  Separation  factor  Flux Index. décimale : 660 Résumé : A novel copoly(4,4′-diphenyleneoxide/1,5-napthalene-2,2′-bis (3,4-dicarboxyl phenyl) hexa fluoro propane diimide) 6FDA-ODA-NDA/Ultem® 1010 dual-layer hollow fiber membrane for pervaporation dehydration has been fabricated via co-extrusion process. Not only can it achieve impressive alcohol dehydration performance without any post-treatment but also it particularly minimizes the membrane's swelling behavior towards aqueous alcohol solution. For isopropanol, n-butanol and t-butanol dehydrations of 85/15 (alcohol/water) wt.% feed solutions, the 6FDA-ODA-NDA/Ultem® 1010 dual-layer hollow fiber membrane can successfully attain permeate containing more than 99.7 wt.% water with considerably high flux which implies to a distinctive separation factor of the respective alcohol system. The outstanding dehydration performance of 6FDA-ODA-NDA/Ultem® 1010 dual-layer hollow fiber membranes on various aqueous alcohol feeds can be attributed to: (1) a precise formulation of the outer- and inner-layer dope compositions; (2) the size of d-space created in the outer-layer is a good match for size exclusion mechanism in the alcohol dehydration systems; (3) a relatively low water uptake and less swelling characteristics of the Ultem® 1010 polyimide as a supporting layer. By adjusting spinning parameters, i.e. outer-layer dope flow rate and air gap distance, the separation performance of 6FDA-ODA-NDA/Ultem® 1010 dual-layer hollow fiber membranes can be further improved. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X7GMP2-4&_user=6 [...] [article] Pervaporation dehydration of C2–C4 alcohols by 6FDA-ODA-NDA/Ultem® dual-layer hollow fiber membranes with enhanced separation performance and swelling resistance [texte imprimé] / Natalia Widjojo, Auteur ; Tai-Shung Chung, Auteur . - 2010 . - pp. 736-743. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 736-743 Mots-clés : Dual-layer  hollow  fiber  membranes  Pervaporation  Alcohol  dehydration  Separation  factor  Flux Index. décimale : 660 Résumé : A novel copoly(4,4′-diphenyleneoxide/1,5-napthalene-2,2′-bis (3,4-dicarboxyl phenyl) hexa fluoro propane diimide) 6FDA-ODA-NDA/Ultem® 1010 dual-layer hollow fiber membrane for pervaporation dehydration has been fabricated via co-extrusion process. Not only can it achieve impressive alcohol dehydration performance without any post-treatment but also it particularly minimizes the membrane's swelling behavior towards aqueous alcohol solution. For isopropanol, n-butanol and t-butanol dehydrations of 85/15 (alcohol/water) wt.% feed solutions, the 6FDA-ODA-NDA/Ultem® 1010 dual-layer hollow fiber membrane can successfully attain permeate containing more than 99.7 wt.% water with considerably high flux which implies to a distinctive separation factor of the respective alcohol system. The outstanding dehydration performance of 6FDA-ODA-NDA/Ultem® 1010 dual-layer hollow fiber membranes on various aqueous alcohol feeds can be attributed to: (1) a precise formulation of the outer- and inner-layer dope compositions; (2) the size of d-space created in the outer-layer is a good match for size exclusion mechanism in the alcohol dehydration systems; (3) a relatively low water uptake and less swelling characteristics of the Ultem® 1010 polyimide as a supporting layer. By adjusting spinning parameters, i.e. outer-layer dope flow rate and air gap distance, the separation performance of 6FDA-ODA-NDA/Ultem® 1010 dual-layer hollow fiber membranes can be further improved. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X7GMP2-4&_user=6 [...]

Promoting effect of adding carbon black to TiO2 for aqueous photocatalytic degradation of methyl orange / Chih-Chung Mao in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 744-749 Titre : Promoting effect of adding carbon black to TiO2 for aqueous photocatalytic degradation of methyl orange Type de document : texte imprimé Auteurs : Chih-Chung Mao, Auteur ; Hung-Shan Weng, Auteur Année de publication : 2010 Article en page(s) : pp. 744-749 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Photocatalytic  degradation  Composite  catalysts  Titania  Carbon  black Index. décimale : 660 Résumé : The photocatalytic activity and the promoting effect of titania (TiO2) incorporated with carbon black (CB) for removing the pollutant in wastewater were investigated. The TiO2/CB composite photocatalysts with various ratios of TiO2 to CB were prepared by the sol–gel method. The degradation of methyl orange (MO), as the model reaction, was carried out in the aqueous slurry solution using these photocatalysts at 20 °C. Experimental results reveal that the ratio of TiO2 to CB largely affected the performance of composite catalyst. An optimal weight ratio of 1 for the highest photocatalytic capability was found. The photocatalytic performances of TiO2/CB catalysts were also found better than those of TiO2 incorporated with activated carbon. The better promoting effect might be attributed to the larger pores of CB which allow a faster diffusion of the adsorbed MO from CB toward TiO2 and the high electrical conductivity of CB which can reduce the recombination of electrons and holes generated in TiO2. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X7GMP2-5&_user=6 [...] [article] Promoting effect of adding carbon black to TiO2 for aqueous photocatalytic degradation of methyl orange [texte imprimé] / Chih-Chung Mao, Auteur ; Hung-Shan Weng, Auteur . - 2010 . - pp. 744-749. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 744-749 Mots-clés : Photocatalytic  degradation  Composite  catalysts  Titania  Carbon  black Index. décimale : 660 Résumé : The photocatalytic activity and the promoting effect of titania (TiO2) incorporated with carbon black (CB) for removing the pollutant in wastewater were investigated. The TiO2/CB composite photocatalysts with various ratios of TiO2 to CB were prepared by the sol–gel method. The degradation of methyl orange (MO), as the model reaction, was carried out in the aqueous slurry solution using these photocatalysts at 20 °C. Experimental results reveal that the ratio of TiO2 to CB largely affected the performance of composite catalyst. An optimal weight ratio of 1 for the highest photocatalytic capability was found. The photocatalytic performances of TiO2/CB catalysts were also found better than those of TiO2 incorporated with activated carbon. The better promoting effect might be attributed to the larger pores of CB which allow a faster diffusion of the adsorbed MO from CB toward TiO2 and the high electrical conductivity of CB which can reduce the recombination of electrons and holes generated in TiO2. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X7GMP2-5&_user=6 [...]

Mechanisms of in-line coalescence of two-unequal bubbles in a non-Newtonian fluid / Tsao-Jen Lin in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 750-756 Titre : Mechanisms of in-line coalescence of two-unequal bubbles in a non-Newtonian fluid Type de document : texte imprimé Auteurs : Tsao-Jen Lin, Auteur ; Gen-Ming Lin, Auteur Année de publication : 2010 Article en page(s) : pp. 750-756 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Bubble  coalescence  Non-Newtonian  fluid  Particle  image  analyzer  Visualization Index. décimale : 660 Résumé : The coalescing mechanism of in-line two-unequal bubbles rising in a bubble column with a non-Newtonian fluid has been experimentally studied. The non-Newtonian fluid is the 1.5 wt% polyacryamide in demineralized water and the bubble gas is air. Both qualitative flow visualization and quantitative full-field measurements using particle image analyzer have been conducted for two examples of two-unequal bubble coalescences. The instantaneous flow structure and the shear stress contour varying in different time lags are presented. As two-unequal bubbles are getting closer, the drained liquid is circulated to the back of the trailing bubble. Due to the drainage flow and the mutual interactions, the flow structure and the shear stress contour show a dramatic change from a two independent bubbles to a single bubble. Due to encounter these dynamic flow structures, the shape of the trailing bubble also has serial changes. However, the case of large trailing bubble with large momentum can affect the deformation of the small leading bubble earlier. Due to the dragging force caused by the negative pressure and the shear-thinning effect and the pushing force caused by the viscoelastic effect, the acceleration of the trailing bubble to the leading bubble is evident. It was found that the coalescence of two-unequal bubbles has higher acceleration than the coalescence of two-equal bubbles. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X8CD4K-1&_user=6 [...] [article] Mechanisms of in-line coalescence of two-unequal bubbles in a non-Newtonian fluid [texte imprimé] / Tsao-Jen Lin, Auteur ; Gen-Ming Lin, Auteur . - 2010 . - pp. 750-756. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 750-756 Mots-clés : Bubble  coalescence  Non-Newtonian  fluid  Particle  image  analyzer  Visualization Index. décimale : 660 Résumé : The coalescing mechanism of in-line two-unequal bubbles rising in a bubble column with a non-Newtonian fluid has been experimentally studied. The non-Newtonian fluid is the 1.5 wt% polyacryamide in demineralized water and the bubble gas is air. Both qualitative flow visualization and quantitative full-field measurements using particle image analyzer have been conducted for two examples of two-unequal bubble coalescences. The instantaneous flow structure and the shear stress contour varying in different time lags are presented. As two-unequal bubbles are getting closer, the drained liquid is circulated to the back of the trailing bubble. Due to the drainage flow and the mutual interactions, the flow structure and the shear stress contour show a dramatic change from a two independent bubbles to a single bubble. Due to encounter these dynamic flow structures, the shape of the trailing bubble also has serial changes. However, the case of large trailing bubble with large momentum can affect the deformation of the small leading bubble earlier. Due to the dragging force caused by the negative pressure and the shear-thinning effect and the pushing force caused by the viscoelastic effect, the acceleration of the trailing bubble to the leading bubble is evident. It was found that the coalescence of two-unequal bubbles has higher acceleration than the coalescence of two-equal bubbles. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X8CD4K-1&_user=6 [...]

Aqueous HCl electrolysis utilizing an oxygen reducing cathode / F. Mohammadi in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 757-762 Titre : Aqueous HCl electrolysis utilizing an oxygen reducing cathode Type de document : texte imprimé Auteurs : F. Mohammadi, Auteur ; S. N. Ashrafizadeh, Auteur ; A. Sattari, Auteur Année de publication : 2010 Article en page(s) : pp. 757-762 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Aqueous  HCl  Electrolysis  Oxygen  reducing  cathode  Membrane  CCE  MEA Index. décimale : 660 Résumé : The effects of various process parameters on the cell voltage and chlorine current efficiency (CCE) in a Half-MEA (Nafion® 115 membrane-Loading: 0.4 mg Pt/cm2) oxygen reducing membrane electrolysis cell employing a dimensionally stable anode (DSA®) were studied. Process parameters under investigation included anolyte concentration, anolyte flow rate, anolyte temperature, oxygen flow rate and applied current density. The effect of the latter parameters on the cell voltage and CCE was determined quantitatively. Taguchi and ANOVA techniques were employed for experimental design and data analysis, respectively. It was observed that increasing either of anolyte flow rate, anolyte concentration, oxygen flow rate and anolyte temperature caused a decrease in cell voltage and an increase in CCE. At the same time, increasing current density linearly increased cell voltage. Current density and the anolyte flow rate had the highest contributions, of 49.7% and 30.62%, to the cell voltage, respectively. On the other hand, the oxygen flow rate and the anolyte flow rate had the highest contributions, of 57.19% and 23.66%, on the CCE, respectively. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X8CD4K-3&_user=6 [...] [article] Aqueous HCl electrolysis utilizing an oxygen reducing cathode [texte imprimé] / F. Mohammadi, Auteur ; S. N. Ashrafizadeh, Auteur ; A. Sattari, Auteur . - 2010 . - pp. 757-762. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 757-762 Mots-clés : Aqueous  HCl  Electrolysis  Oxygen  reducing  cathode  Membrane  CCE  MEA Index. décimale : 660 Résumé : The effects of various process parameters on the cell voltage and chlorine current efficiency (CCE) in a Half-MEA (Nafion® 115 membrane-Loading: 0.4 mg Pt/cm2) oxygen reducing membrane electrolysis cell employing a dimensionally stable anode (DSA®) were studied. Process parameters under investigation included anolyte concentration, anolyte flow rate, anolyte temperature, oxygen flow rate and applied current density. The effect of the latter parameters on the cell voltage and CCE was determined quantitatively. Taguchi and ANOVA techniques were employed for experimental design and data analysis, respectively. It was observed that increasing either of anolyte flow rate, anolyte concentration, oxygen flow rate and anolyte temperature caused a decrease in cell voltage and an increase in CCE. At the same time, increasing current density linearly increased cell voltage. Current density and the anolyte flow rate had the highest contributions, of 49.7% and 30.62%, to the cell voltage, respectively. On the other hand, the oxygen flow rate and the anolyte flow rate had the highest contributions, of 57.19% and 23.66%, on the CCE, respectively. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X8CD4K-3&_user=6 [...]

Electrochemical regeneration of granular activated carbon saturated with organic compounds / Lizhang Wang in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 763-768 Titre : Electrochemical regeneration of granular activated carbon saturated with organic compounds Type de document : texte imprimé Auteurs : Lizhang Wang, Auteur ; N. Balasubramanian, Auteur Année de publication : 2010 Article en page(s) : pp. 763-768 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Granular  activated  carbon  Electrochemical  regeneration  Adsorption  Kinetics Index. décimale : 660 Résumé : Electrochemical regeneration of granular activated carbon (GAC) saturated with organic compounds was investigated using SnO2/Ti anodes. Experiments were carried out under a semi-batch electrochemical reactor covering wide range in operating conditions. A kinetic model has been developed to describe the electrochemical regeneration and the performance indicators such as instantaneous current efficiency and regeneration efficiency were estimated. The proposed model has been effectively demonstrated for the regeneration of GAC saturated with organics present in the 4,4′-diamino stilbene-2,2′-disulfonic acid manufacturing wastewater. It has been observed from the present experiments that the applied current density has significant influence on adsorption capacity of regenerated GAC. A good agreement of the model predictions with the experimental observations shows that the proposed kinetic model can be used as a better design method for electrochemical regeneration of spent GAC. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X8CD4K-2&_user=6 [...] [article] Electrochemical regeneration of granular activated carbon saturated with organic compounds [texte imprimé] / Lizhang Wang, Auteur ; N. Balasubramanian, Auteur . - 2010 . - pp. 763-768. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 763-768 Mots-clés : Granular  activated  carbon  Electrochemical  regeneration  Adsorption  Kinetics Index. décimale : 660 Résumé : Electrochemical regeneration of granular activated carbon (GAC) saturated with organic compounds was investigated using SnO2/Ti anodes. Experiments were carried out under a semi-batch electrochemical reactor covering wide range in operating conditions. A kinetic model has been developed to describe the electrochemical regeneration and the performance indicators such as instantaneous current efficiency and regeneration efficiency were estimated. The proposed model has been effectively demonstrated for the regeneration of GAC saturated with organics present in the 4,4′-diamino stilbene-2,2′-disulfonic acid manufacturing wastewater. It has been observed from the present experiments that the applied current density has significant influence on adsorption capacity of regenerated GAC. A good agreement of the model predictions with the experimental observations shows that the proposed kinetic model can be used as a better design method for electrochemical regeneration of spent GAC. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X8CD4K-2&_user=6 [...]

Fenton and Fenton-like reaction followed by hydroxide precipitation in the removal of Ni(II) from NiEDTA wastewater / Fenglian Fu in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 769-774 Titre : Fenton and Fenton-like reaction followed by hydroxide precipitation in the removal of Ni(II) from NiEDTA wastewater : a comparative study Type de document : texte imprimé Auteurs : Fenglian Fu, Auteur ; Qi Wang, Auteur ; Bing Tang, Auteur Année de publication : 2010 Article en page(s) : pp. 769-774 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : NiEDTA  wastewater  FR-HP  process  Fenton  reaction  Fenton-like  reaction Index. décimale : 660 Résumé : It is difficult to remove Ni(II) from NiEDTA wastewater by many conventional processes. A new method for removing Ni(II) from NiEDTA wastewater by Fenton and Fenton-like reaction followed by hydroxide precipitation presents an important breakthrough. This treatment process is referred to as Fenton/Fenton-like reaction-hydroxide precipitation (FR-HP) process. This study investigated the use of FR-HP process for the removal of Ni(II) from NiEDTA complex wastewater. The removal efficiency of Ni(II) by FR-HP process was investigated and the kinetics of the two processes was studied. Results indicated that the removal efficiency was strongly dependent on the initial concentration of Fe2+ or Fe3+ and H2O2, initial and precipitation pH and temperature. Both FR-HP processes can effectively remove Ni(II). At optimal operation conditions, the removal efficiency of Ni(II) were 92.8% and 94.7% for Fenton and Fenton-like systems after 60 min, respectively. FR-HP process seems to be an economically and environmentally friendly process to remove the metal from metal–EDTA wastewater. Hopefully, FR-HP process will promote the development of metal–EDTA treatment technology. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X908Y5-3&_user=6 [...] [article] Fenton and Fenton-like reaction followed by hydroxide precipitation in the removal of Ni(II) from NiEDTA wastewater : a comparative study [texte imprimé] / Fenglian Fu, Auteur ; Qi Wang, Auteur ; Bing Tang, Auteur . - 2010 . - pp. 769-774. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 769-774 Mots-clés : NiEDTA  wastewater  FR-HP  process  Fenton  reaction  Fenton-like  reaction Index. décimale : 660 Résumé : It is difficult to remove Ni(II) from NiEDTA wastewater by many conventional processes. A new method for removing Ni(II) from NiEDTA wastewater by Fenton and Fenton-like reaction followed by hydroxide precipitation presents an important breakthrough. This treatment process is referred to as Fenton/Fenton-like reaction-hydroxide precipitation (FR-HP) process. This study investigated the use of FR-HP process for the removal of Ni(II) from NiEDTA complex wastewater. The removal efficiency of Ni(II) by FR-HP process was investigated and the kinetics of the two processes was studied. Results indicated that the removal efficiency was strongly dependent on the initial concentration of Fe2+ or Fe3+ and H2O2, initial and precipitation pH and temperature. Both FR-HP processes can effectively remove Ni(II). At optimal operation conditions, the removal efficiency of Ni(II) were 92.8% and 94.7% for Fenton and Fenton-like systems after 60 min, respectively. FR-HP process seems to be an economically and environmentally friendly process to remove the metal from metal–EDTA wastewater. Hopefully, FR-HP process will promote the development of metal–EDTA treatment technology. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X908Y5-3&_user=6 [...]

Chitosan flocculation of cardboard-mill secondary biological wastewater / François Renault in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 775-783 Titre : Chitosan flocculation of cardboard-mill secondary biological wastewater Type de document : texte imprimé Auteurs : François Renault, Auteur ; Bertrand Sancey, Auteur ; Jérémie Charles, Auteur Année de publication : 2010 Article en page(s) : pp. 775-783 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Bioflocculation  Biological  wastewater  Chitosan  Polyaluminium  chloride  (PAC)  Temperature Index. décimale : 660 Résumé : Flocculation is a common secondary treatment procedure for the removal of suspended solids, colloids and organic matter present in industrial wastewater. In the present study, the flocculation of cardboard industry wastewater, treated by a biological process in an aerated lagoon, was examined using commercial grade polyaluminium chloride (PAC) and chitosan (CHITO) dissolved in acetic acid as flocculating agents. A series of flocculation jar-tests was conducted under different conditions. The influence of the flocculant dosage and the temperature of the lagoon on the quality of the treated wastewater was investigated. Optimum temperature for PAC was in the range 13–21 °C for a dosage of 0.3–0.4 mL L−1 but the results were highly temperature-dependent; PAC lowered chemical oxygen demand (COD) by 40–45% and turbidity by 55–60%. With CHITO, the process was more efficient than with PAC for an effective dosage of 7 mL L−1 and no influence of temperature was observed. Chitosan lowered the COD by over 80% and turbidity by more than 85%. It generated bigger flocs making settling faster than with PAC. It also removed residual colour and led to a significant decrease in the amount of heavy metals present in the effluent. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X908Y5-2&_user=6 [...] [article] Chitosan flocculation of cardboard-mill secondary biological wastewater [texte imprimé] / François Renault, Auteur ; Bertrand Sancey, Auteur ; Jérémie Charles, Auteur . - 2010 . - pp. 775-783. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 775-783 Mots-clés : Bioflocculation  Biological  wastewater  Chitosan  Polyaluminium  chloride  (PAC)  Temperature Index. décimale : 660 Résumé : Flocculation is a common secondary treatment procedure for the removal of suspended solids, colloids and organic matter present in industrial wastewater. In the present study, the flocculation of cardboard industry wastewater, treated by a biological process in an aerated lagoon, was examined using commercial grade polyaluminium chloride (PAC) and chitosan (CHITO) dissolved in acetic acid as flocculating agents. A series of flocculation jar-tests was conducted under different conditions. The influence of the flocculant dosage and the temperature of the lagoon on the quality of the treated wastewater was investigated. Optimum temperature for PAC was in the range 13–21 °C for a dosage of 0.3–0.4 mL L−1 but the results were highly temperature-dependent; PAC lowered chemical oxygen demand (COD) by 40–45% and turbidity by 55–60%. With CHITO, the process was more efficient than with PAC for an effective dosage of 7 mL L−1 and no influence of temperature was observed. Chitosan lowered the COD by over 80% and turbidity by more than 85%. It generated bigger flocs making settling faster than with PAC. It also removed residual colour and led to a significant decrease in the amount of heavy metals present in the effluent. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X908Y5-2&_user=6 [...]

Extraction equilibria of propionic acid from aqueous solutions by Amberlite LA-2 in diluent solvents / Yavuz Selim Asci in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 784-788 Titre : Extraction equilibria of propionic acid from aqueous solutions by Amberlite LA-2 in diluent solvents Type de document : texte imprimé Auteurs : Yavuz Selim Asci, Auteur ; Ismail Inci, Auteur Année de publication : 2010 Article en page(s) : pp. 784-788 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Extraction  Propionic  acid  Amberlite  LA-2 Index. décimale : 660 Résumé : Amberlite LA-2 (a secondary amine) was studied for its ability to extract propionic acid at different amine concentrations. The extraction of propionic acid by Amberlite LA-2 dissolved in seven single solvents (cyclohexane, 2-octanone, toluene, methyl isobutyl ketone, isooctane, haxane and 1-octanol) was investigated under various amine concentrations at 298.15 K. Using Bizek's approach, two acids: amine complexes, (HO):(R2N) and (HO):(R2N)2, are assumed to exist in the organic phase in case of proton-donating diluents, while the complexes (HO):(R2N) and (HO)2:(R2N)3 are suggested in the case of non-proton-donating diluents. Important data for design of separation units have been obtained as a result of batch experiments. These data are distribution coefficients (D), loading factors (Z), extraction efficiency (E) and overall extraction constants (K11, K12, K23). The maximum removal of glycolic acid is 94.68% with MIBK and 0.93 mol L−1 initial concentration of Amberlite LA-2. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X97D48-1&_user=6 [...] [article] Extraction equilibria of propionic acid from aqueous solutions by Amberlite LA-2 in diluent solvents [texte imprimé] / Yavuz Selim Asci, Auteur ; Ismail Inci, Auteur . - 2010 . - pp. 784-788. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 784-788 Mots-clés : Extraction  Propionic  acid  Amberlite  LA-2 Index. décimale : 660 Résumé : Amberlite LA-2 (a secondary amine) was studied for its ability to extract propionic acid at different amine concentrations. The extraction of propionic acid by Amberlite LA-2 dissolved in seven single solvents (cyclohexane, 2-octanone, toluene, methyl isobutyl ketone, isooctane, haxane and 1-octanol) was investigated under various amine concentrations at 298.15 K. Using Bizek's approach, two acids: amine complexes, (HO):(R2N) and (HO):(R2N)2, are assumed to exist in the organic phase in case of proton-donating diluents, while the complexes (HO):(R2N) and (HO)2:(R2N)3 are suggested in the case of non-proton-donating diluents. Important data for design of separation units have been obtained as a result of batch experiments. These data are distribution coefficients (D), loading factors (Z), extraction efficiency (E) and overall extraction constants (K11, K12, K23). The maximum removal of glycolic acid is 94.68% with MIBK and 0.93 mol L−1 initial concentration of Amberlite LA-2. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X97D48-1&_user=6 [...]

Oscillator micromixer / V. Tesar in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 789-799 Titre : Oscillator micromixer Type de document : texte imprimé Auteurs : V. Tesar, Auteur Année de publication : 2010 Article en page(s) : pp. 789-799 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Fluidics  Mixer  Micromixer  Oscillator Index. décimale : 660 Résumé : A no-moving-part microfluidic oscillator was developed for mixing two reactants prior to their admission into a microreactor. Instead of the spatial periodicity produced by static mixers, it achieves essentially the same resultant effect by temporal periodicity. In one half of the oscillation period the oscillator directs into its output one reactant, followed by the other reactant during the other half-period. Since the periods are short, the flow in the output channel consists, like in the static mixers, of interleaved layers of the two fluids – here, however, oriented perpendicularly relative to the flow direction. The oscillation depends on dynamic effects so that there is a lower limit of Reynolds numbers at which the device can operate. In experiments this limit was at Re not, vert, similar30, which makes the device well suited for use with present-day microreactors, especially if the mixer is used to supply several reactors in parallel. Data from experiments with two different models agree with very simple kinematic theory for oscillation frequency and for the size of the generated layers in the output. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X378K2-1&_user=6 [...] [article] Oscillator micromixer [texte imprimé] / V. Tesar, Auteur . - 2010 . - pp. 789-799. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 789-799 Mots-clés : Fluidics  Mixer  Micromixer  Oscillator Index. décimale : 660 Résumé : A no-moving-part microfluidic oscillator was developed for mixing two reactants prior to their admission into a microreactor. Instead of the spatial periodicity produced by static mixers, it achieves essentially the same resultant effect by temporal periodicity. In one half of the oscillation period the oscillator directs into its output one reactant, followed by the other reactant during the other half-period. Since the periods are short, the flow in the output channel consists, like in the static mixers, of interleaved layers of the two fluids – here, however, oriented perpendicularly relative to the flow direction. The oscillation depends on dynamic effects so that there is a lower limit of Reynolds numbers at which the device can operate. In experiments this limit was at Re not, vert, similar30, which makes the device well suited for use with present-day microreactors, especially if the mixer is used to supply several reactors in parallel. Data from experiments with two different models agree with very simple kinematic theory for oscillation frequency and for the size of the generated layers in the output. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X378K2-1&_user=6 [...]

Intensifying esterification reaction between lactic acid and ethanol by pervaporation dehydration using chitosan–TEOS hybrid membranes / Jing Ma in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 800-809 Titre : Intensifying esterification reaction between lactic acid and ethanol by pervaporation dehydration using chitosan–TEOS hybrid membranes Type de document : texte imprimé Auteurs : Jing Ma, Auteur ; Minhua Zhang, Auteur ; Lianyu Lu, Auteur Année de publication : 2010 Article en page(s) : pp. 800-809 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Pervaporation  Hybrid  membrane  Intensification  Ethyl  lactate  Esterification Index. décimale : 660 Résumé : Esterification assisted by pervaporation separation can enhance the yield of ester for thermodynamically or kinetically limited reaction via selective removal of water from the reaction mixture. In the present study, organic–inorganic hybrid membranes were prepared by in situ hydrolysis and condensation of tetraethoxysilane (TEOS) within chitosan (CS) aqueous solution for pervaporation-assisted esterification of lactic acid with ethanol, catalyzed by Amberlyst 15 ion-exchange resin. The composition and structural properties of CS–TEOS hybrid membranes were investigated by FT-IR, XRD, TGA and contact angle. The dehydration performances of hybrid membranes were evaluated by pervaporation of aqueous ethanol solution. Comparing with CS pristine membrane, CS–TEOS hybrid membranes exhibited remarkably enhancing pervaporation property. Pervaporation-assisted esterification results suggested that the incorporation of pervaporation process to preferentially remove water from the reaction mixture substantially enhanced the yield of ethyl lactate from 66 wt.% to 80 wt.%. The effects of membrane casting solution recipe, reaction temperature, initial molar ratio of ethanol to lactic acid and catalyst loading amount on the process performance have been examined in detail. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4WXBMGH-2&_user=6 [...] [article] Intensifying esterification reaction between lactic acid and ethanol by pervaporation dehydration using chitosan–TEOS hybrid membranes [texte imprimé] / Jing Ma, Auteur ; Minhua Zhang, Auteur ; Lianyu Lu, Auteur . - 2010 . - pp. 800-809. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 800-809 Mots-clés : Pervaporation  Hybrid  membrane  Intensification  Ethyl  lactate  Esterification Index. décimale : 660 Résumé : Esterification assisted by pervaporation separation can enhance the yield of ester for thermodynamically or kinetically limited reaction via selective removal of water from the reaction mixture. In the present study, organic–inorganic hybrid membranes were prepared by in situ hydrolysis and condensation of tetraethoxysilane (TEOS) within chitosan (CS) aqueous solution for pervaporation-assisted esterification of lactic acid with ethanol, catalyzed by Amberlyst 15 ion-exchange resin. The composition and structural properties of CS–TEOS hybrid membranes were investigated by FT-IR, XRD, TGA and contact angle. The dehydration performances of hybrid membranes were evaluated by pervaporation of aqueous ethanol solution. Comparing with CS pristine membrane, CS–TEOS hybrid membranes exhibited remarkably enhancing pervaporation property. Pervaporation-assisted esterification results suggested that the incorporation of pervaporation process to preferentially remove water from the reaction mixture substantially enhanced the yield of ethyl lactate from 66 wt.% to 80 wt.%. The effects of membrane casting solution recipe, reaction temperature, initial molar ratio of ethanol to lactic acid and catalyst loading amount on the process performance have been examined in detail. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4WXBMGH-2&_user=6 [...]

Laccase catalysed conjugation of catechin with poly(allylamine) / Parikshit Gogoi in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 810-815 Titre : Laccase catalysed conjugation of catechin with poly(allylamine) : solvent effect Type de document : texte imprimé Auteurs : Parikshit Gogoi, Auteur ; Swapnali Hazarika, Auteur ; Narendra N. Dutta, Auteur Année de publication : 2010 Article en page(s) : pp. 810-815 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Laccase  Catechin  Poly(allylamine)  Solvent  effect Résumé : The Trametes versicolor laccase catalysed the synthesis of poly(allylamine) catechin conjugate by conjugation of catechin with poly(allylamine) was studied in 11 different solvents in order to deduce the solvent effect through an attempt to correlate the initial reaction rate with solvent properties such as hydrophobicity (log P), water solubility (log Sw), electron pair acceptance (View the MathML source) and donation abilities (View the MathML source), polarisibility and dielectric constant. The initial rate was found to exhibit reasonable correlation with log P, log Sw, View the MathML source, polarisibility and dielectric constant. The probable explanation for the deviation has been put forward based on established hypothesis. The study revealed, in general that polar solvents favour the initial reaction rate. The organic solvent interferes neither with the laccase–substrate binding process nor with the catalytic mechanism. The contribution of the substrate–solvent interactions to enzyme kinetics was accounted by replacing the substrate concentration by thermodynamic activities. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4WXBMGH-5&_user=6 [...] [article] Laccase catalysed conjugation of catechin with poly(allylamine) : solvent effect [texte imprimé] / Parikshit Gogoi, Auteur ; Swapnali Hazarika, Auteur ; Narendra N. Dutta, Auteur . - 2010 . - pp. 810-815. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 810-815 Mots-clés : Laccase  Catechin  Poly(allylamine)  Solvent  effect Résumé : The Trametes versicolor laccase catalysed the synthesis of poly(allylamine) catechin conjugate by conjugation of catechin with poly(allylamine) was studied in 11 different solvents in order to deduce the solvent effect through an attempt to correlate the initial reaction rate with solvent properties such as hydrophobicity (log P), water solubility (log Sw), electron pair acceptance (View the MathML source) and donation abilities (View the MathML source), polarisibility and dielectric constant. The initial rate was found to exhibit reasonable correlation with log P, log Sw, View the MathML source, polarisibility and dielectric constant. The probable explanation for the deviation has been put forward based on established hypothesis. The study revealed, in general that polar solvents favour the initial reaction rate. The organic solvent interferes neither with the laccase–substrate binding process nor with the catalytic mechanism. The contribution of the substrate–solvent interactions to enzyme kinetics was accounted by replacing the substrate concentration by thermodynamic activities. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4WXBMGH-5&_user=6 [...]

Experimental errors in kinetic tests and its influence on the precision of estimated parameters. Part I, Analysis of first-order reactions / André L. Alberton in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 816-823 Titre : Experimental errors in kinetic tests and its influence on the precision of estimated parameters. Part I, Analysis of first-order reactions Type de document : texte imprimé Auteurs : André L. Alberton, Auteur ; Marcio Schwaab, Auteur ; Martin Schmal, Auteur Année de publication : 2010 Article en page(s) : pp. 816-823 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Experimental  error  Kinetic  analysis  First-order  reaction  Precise  parameter  estimation Index. décimale : 660 Résumé : The proper characterization of the experimental errors is essential for the correct evaluation of estimated model parameters, model fit and model predictions based on kinetic rate expressions. However, it is common to ignore the influence of experimental errors during kinetic studies due to difficulties to characterize how experimental errors depend on the reaction conditions. The behavior of experimental error depends on the specific features of the experimental system; however, in many cases the main sources of experimental errors are the unavoidable oscillations of the input variables. This work analyzes how the experimental errors affect kinetic studies based on catalytic tests when oscillations of the input variables are the main sources of uncertainties. The first part of this work assumes that the reaction rate can be described accurately as a first-order reaction in a PFR. Analytical expressions are derived for the variance of the reactant conversion in distinct scenarios and are used to analyze the quality of the obtained parameter estimates. It is shown here that the conversion variances can be described as functions of the measured conversion values, normally presenting a point of maximum for conversion values in the range of 0.6 < X < 1.0 when observed experimental fluctuations are controlled by the fluctuations of the input variables. Constant conversion variances should be expected only when fluctuations are controlled by analytical conversion measurements. As a consequence, optimum parameter estimation may be performed either with differential or integral methods, depending on the behavior of the conversion variances. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X24VV2-4&_user=6 [...] [article] Experimental errors in kinetic tests and its influence on the precision of estimated parameters. Part I, Analysis of first-order reactions [texte imprimé] / André L. Alberton, Auteur ; Marcio Schwaab, Auteur ; Martin Schmal, Auteur . - 2010 . - pp. 816-823. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 816-823 Mots-clés : Experimental  error  Kinetic  analysis  First-order  reaction  Precise  parameter  estimation Index. décimale : 660 Résumé : The proper characterization of the experimental errors is essential for the correct evaluation of estimated model parameters, model fit and model predictions based on kinetic rate expressions. However, it is common to ignore the influence of experimental errors during kinetic studies due to difficulties to characterize how experimental errors depend on the reaction conditions. The behavior of experimental error depends on the specific features of the experimental system; however, in many cases the main sources of experimental errors are the unavoidable oscillations of the input variables. This work analyzes how the experimental errors affect kinetic studies based on catalytic tests when oscillations of the input variables are the main sources of uncertainties. The first part of this work assumes that the reaction rate can be described accurately as a first-order reaction in a PFR. Analytical expressions are derived for the variance of the reactant conversion in distinct scenarios and are used to analyze the quality of the obtained parameter estimates. It is shown here that the conversion variances can be described as functions of the measured conversion values, normally presenting a point of maximum for conversion values in the range of 0.6 < X < 1.0 when observed experimental fluctuations are controlled by the fluctuations of the input variables. Constant conversion variances should be expected only when fluctuations are controlled by analytical conversion measurements. As a consequence, optimum parameter estimation may be performed either with differential or integral methods, depending on the behavior of the conversion variances. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X24VV2-4&_user=6 [...]

Gold catalysts / Kenneth Wong in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 824-828 Titre : Gold catalysts : a new insight into the molecular adsorption and CO oxidation Type de document : texte imprimé Auteurs : Kenneth Wong, Auteur ; Qinghua Zeng, Auteur ; Aibing Yu, Auteur Année de publication : 2010 Article en page(s) : pp. 824-828 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Heterogeneous  catalyst  Molecular  adsorption  CO  oxidation  Molecular  dynamics  simulation Index. décimale : 660 Résumé : The molecular adsorption and CO oxidation on a gold-deposited TiO2 catalyst were investigated by means of molecular dynamics simulation. The results indicate that the molecules (i.e., O2, CO, and H2O) are selectively adsorbed on the specific locations such as gold particle, gold-support perimeter interface, and support surface. The adsorption and dissociation of H2O molecules at the perimeter interface enhance the supply of oxygen, thus promoting the oxidation of CO on the Au/TiO2 catalyst. However, the presence of Cl− ions could significantly impede CO oxidation due to their competition with O2, CO, and H2O for the adsorption sites. A reaction mechanism of CO oxidation is postulated on this basis. The findings are useful in developing a comprehensive picture about CO oxidation on gold-deposited TiO2 and in the design of new gold catalysts with high catalytic activity. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X60TG2-1&_user=6 [...] [article] Gold catalysts : a new insight into the molecular adsorption and CO oxidation [texte imprimé] / Kenneth Wong, Auteur ; Qinghua Zeng, Auteur ; Aibing Yu, Auteur . - 2010 . - pp. 824-828. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 824-828 Mots-clés : Heterogeneous  catalyst  Molecular  adsorption  CO  oxidation  Molecular  dynamics  simulation Index. décimale : 660 Résumé : The molecular adsorption and CO oxidation on a gold-deposited TiO2 catalyst were investigated by means of molecular dynamics simulation. The results indicate that the molecules (i.e., O2, CO, and H2O) are selectively adsorbed on the specific locations such as gold particle, gold-support perimeter interface, and support surface. The adsorption and dissociation of H2O molecules at the perimeter interface enhance the supply of oxygen, thus promoting the oxidation of CO on the Au/TiO2 catalyst. However, the presence of Cl− ions could significantly impede CO oxidation due to their competition with O2, CO, and H2O for the adsorption sites. A reaction mechanism of CO oxidation is postulated on this basis. The findings are useful in developing a comprehensive picture about CO oxidation on gold-deposited TiO2 and in the design of new gold catalysts with high catalytic activity. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X60TG2-1&_user=6 [...]

A one-step conversion of benzene to phenol using MEMS-based Pd membrane microreactors / Shu-Ying Ye in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 829-837 Titre : A one-step conversion of benzene to phenol using MEMS-based Pd membrane microreactors Type de document : texte imprimé Auteurs : Shu-Ying Ye, Auteur ; Satoshi Hamakawa, Auteur ; Shuji Tanaka, Auteur Année de publication : 2010 Article en page(s) : pp. 829-837 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : MEMS  (micro-electro-mechanical  system)  Microreactor  Pd  membrane  Hydrogen  permeation  Direct  hydroxylation  Benzene  Phenol Index. décimale : 660 Résumé : We have developed an MEMS-based Pd membrane microreactor for one-step conversion of benzene to phenol, and also evaluated the H2 permeation characteristics through the Pd membrane before the benzene hydroxylation experiments. The conversion of benzene, selectivity and yield of phenol were investigated by varying the operation conditions. The phenol yield of 20% and benzene conversion of 54% were obtained at a reaction temperature of 200 °C. The phenol and dihydric phenols dominated the distribution of products and the hydrogenation products of from benzene and phenol were absent in the MEMS-based Pd membrane microreactor, which was very different from the macrotubular Pd membrane reactors. The effect of H2/O2 ratio on products distribution has been investigated. From the comparison of reaction results with a macrotubular Pd membrane reactor, it is figured out that the Pd membrane microreactors fabricated by MEMS technology gave a higher reaction conversion and product yield. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X66S91-1&_user=6 [...] [article] A one-step conversion of benzene to phenol using MEMS-based Pd membrane microreactors [texte imprimé] / Shu-Ying Ye, Auteur ; Satoshi Hamakawa, Auteur ; Shuji Tanaka, Auteur . - 2010 . - pp. 829-837. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 829-837 Mots-clés : MEMS  (micro-electro-mechanical  system)  Microreactor  Pd  membrane  Hydrogen  permeation  Direct  hydroxylation  Benzene  Phenol Index. décimale : 660 Résumé : We have developed an MEMS-based Pd membrane microreactor for one-step conversion of benzene to phenol, and also evaluated the H2 permeation characteristics through the Pd membrane before the benzene hydroxylation experiments. The conversion of benzene, selectivity and yield of phenol were investigated by varying the operation conditions. The phenol yield of 20% and benzene conversion of 54% were obtained at a reaction temperature of 200 °C. The phenol and dihydric phenols dominated the distribution of products and the hydrogenation products of from benzene and phenol were absent in the MEMS-based Pd membrane microreactor, which was very different from the macrotubular Pd membrane reactors. The effect of H2/O2 ratio on products distribution has been investigated. From the comparison of reaction results with a macrotubular Pd membrane reactor, it is figured out that the Pd membrane microreactors fabricated by MEMS technology gave a higher reaction conversion and product yield. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X66S91-1&_user=6 [...]

Stabilization of a CSTR with two arbitrarily switching modes using modal state feedback linearization / M. Barkhordari Yazdi in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 838-843 Titre : Stabilization of a CSTR with two arbitrarily switching modes using modal state feedback linearization Type de document : texte imprimé Auteurs : M. Barkhordari Yazdi, Auteur ; M.R. Jahed-Motlagh, Auteur Année de publication : 2010 Article en page(s) : pp. 838-843 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Switched  systems  Continuous  stirred  tank  reactor  Arbitrary  switching  Feedback  linearization  Stabilization Index. décimale : 660 Résumé : The problem of controller synthesis with the objective of stabilizing a continuous stirred tank reactor (CSTR) with arbitrary switching between two modes, is considered. First, based on the new concept of modal state feedback linearization, two nonlinear state feedback laws and a nonlinear state transformation are synthesized. The advantage of this step is to transform the switched nonlinear model of the CSTR to an equivalent switched linear system without any approximation. In the second step, a stabilizing controller is designed for the switched linear system using the common Lyapunov function theory. Although it is proven that the process is globally stabilized with the designed controller, the performance of the controller is also shown in simulation. This paper illustrates the possibility of simplifying the procedure of designing controller for switched nonlinear processes, using the modal state feedback method. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X66S91-2&_user=6 [...] [article] Stabilization of a CSTR with two arbitrarily switching modes using modal state feedback linearization [texte imprimé] / M. Barkhordari Yazdi, Auteur ; M.R. Jahed-Motlagh, Auteur . - 2010 . - pp. 838-843. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 838-843 Mots-clés : Switched  systems  Continuous  stirred  tank  reactor  Arbitrary  switching  Feedback  linearization  Stabilization Index. décimale : 660 Résumé : The problem of controller synthesis with the objective of stabilizing a continuous stirred tank reactor (CSTR) with arbitrary switching between two modes, is considered. First, based on the new concept of modal state feedback linearization, two nonlinear state feedback laws and a nonlinear state transformation are synthesized. The advantage of this step is to transform the switched nonlinear model of the CSTR to an equivalent switched linear system without any approximation. In the second step, a stabilizing controller is designed for the switched linear system using the common Lyapunov function theory. Although it is proven that the process is globally stabilized with the designed controller, the performance of the controller is also shown in simulation. This paper illustrates the possibility of simplifying the procedure of designing controller for switched nonlinear processes, using the modal state feedback method. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X66S91-2&_user=6 [...]

Synthesis, characterization and application of triethylenetetramine modified polystyrene resin in removal of mercury, cadmium and lead from aqueous solutions / Chunhua Xiong in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 844-850 Titre : Synthesis, characterization and application of triethylenetetramine modified polystyrene resin in removal of mercury, cadmium and lead from aqueous solutions Type de document : texte imprimé Auteurs : Chunhua Xiong, Auteur ; Caiping Yao, Auteur Année de publication : 2010 Article en page(s) : pp. 844-850 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Triethylenetetramine  Chelating  resin  Synthesis  Heavy  metal  Adsorption Index. décimale : 660 Résumé : Polystyrene-triethylenetetramine resin (PS-TETA) was synthesized from chloromethylated polystyrene (PS-Cl) and triethylenetetramine (TETA) and employed as a new adsorbent for heavy metal removal from aqueous solutions. The effects of reaction parameters (reaction solvent, molar ratio of reagents, reaction temperature and reaction time) on the functional group capacity of PS-TETA resin were monitored to specify the best synthesis conditions. The functional group capacity and conversion percentage of functional group of PS-TETA prepared under the optimum condition were 2.13 mmol FG/g and 49.79%, respectively. The structure of PS-TETA was confirmed by elemental analysis and infrared spectra. The optimization of experimental conditions and parameters including pH, contact time, initial metal ion concentration for the removal of heavy metals were investigated. The maximum adsorption capacities of the resin for Hg(II), Cd(II) and Pb(II) evaluated from the Langmuir model were 344.8, 212.8 and 147.1 mg/g, respectively. Desorption studies revealed that Hg(II), Cd(II) and Pb(II) can be easily removed from PS-TETA by altering the pH values of the solution using HCl, which indicate that PS-TETA is a promising adsorbent for heavy metals removal from aqueous medium. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X66S91-3&_user=6 [...] [article] Synthesis, characterization and application of triethylenetetramine modified polystyrene resin in removal of mercury, cadmium and lead from aqueous solutions [texte imprimé] / Chunhua Xiong, Auteur ; Caiping Yao, Auteur . - 2010 . - pp. 844-850. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 844-850 Mots-clés : Triethylenetetramine  Chelating  resin  Synthesis  Heavy  metal  Adsorption Index. décimale : 660 Résumé : Polystyrene-triethylenetetramine resin (PS-TETA) was synthesized from chloromethylated polystyrene (PS-Cl) and triethylenetetramine (TETA) and employed as a new adsorbent for heavy metal removal from aqueous solutions. The effects of reaction parameters (reaction solvent, molar ratio of reagents, reaction temperature and reaction time) on the functional group capacity of PS-TETA resin were monitored to specify the best synthesis conditions. The functional group capacity and conversion percentage of functional group of PS-TETA prepared under the optimum condition were 2.13 mmol FG/g and 49.79%, respectively. The structure of PS-TETA was confirmed by elemental analysis and infrared spectra. The optimization of experimental conditions and parameters including pH, contact time, initial metal ion concentration for the removal of heavy metals were investigated. The maximum adsorption capacities of the resin for Hg(II), Cd(II) and Pb(II) evaluated from the Langmuir model were 344.8, 212.8 and 147.1 mg/g, respectively. Desorption studies revealed that Hg(II), Cd(II) and Pb(II) can be easily removed from PS-TETA by altering the pH values of the solution using HCl, which indicate that PS-TETA is a promising adsorbent for heavy metals removal from aqueous medium. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X66S91-3&_user=6 [...]

Role of nitrous acid decomposition in absorber and bleacher in nitric acid plant / N.D. Ingale in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 851-858 Titre : Role of nitrous acid decomposition in absorber and bleacher in nitric acid plant Type de document : texte imprimé Auteurs : N.D. Ingale, Auteur ; I. B. Chatterjee, Auteur ; J.B. Joshi, Auteur Année de publication : 2010 Article en page(s) : pp. 851-858 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : HNO2  decomposition  HNO2  oxidation  with  O2  NO  oxidation  with  HNO3  Multi-component  absorption  and  desorption  with  chemical  reaction  HNO3  and  HNO2  concentration  profile  in  absorber  HNO2  concentration  profile  in  bleacher  NOx  absorption Index. décimale : 660 Résumé : The stringent statutory regulation for clean environment makes the absorber and the bleacher in the nitric acid plant two very important equipments. The NOx finally released to the atmosphere from the absorber, is based on the mathematical calculations of the nitric acid and nitrous acid concentration profiles along the length of the absorber. The present work focuses on the role of HNO2 decomposition in the absorber and the bleacher in the nitric acid plant. The decomposition of HNO2 is a heterogeneous reaction resulting into the formation of nitric acid and desorption of nitric oxide. At high nitric acid concentration (40–50 wt.%), the reversibility of HNO2 decomposition due to NO oxidation with nitric acid is important. The model for bleacher column is presented, which takes into account the de-colorization of the product acid from the absorption column and makes it free from the nitrous acid. The model for the bleacher also takes into account the decomposition and oxidation of HNO2 with dissolved oxygen. The models proposed for absorber and bleacher are validated from the data collected from a mono-pressure nitric acid plant as well as the data present in open literature. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X7R86W-1&_user=6 [...] [article] Role of nitrous acid decomposition in absorber and bleacher in nitric acid plant [texte imprimé] / N.D. Ingale, Auteur ; I. B. Chatterjee, Auteur ; J.B. Joshi, Auteur . - 2010 . - pp. 851-858. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 851-858 Mots-clés : HNO2  decomposition  HNO2  oxidation  with  O2  NO  oxidation  with  HNO3  Multi-component  absorption  and  desorption  with  chemical  reaction  HNO3  and  HNO2  concentration  profile  in  absorber  HNO2  concentration  profile  in  bleacher  NOx  absorption Index. décimale : 660 Résumé : The stringent statutory regulation for clean environment makes the absorber and the bleacher in the nitric acid plant two very important equipments. The NOx finally released to the atmosphere from the absorber, is based on the mathematical calculations of the nitric acid and nitrous acid concentration profiles along the length of the absorber. The present work focuses on the role of HNO2 decomposition in the absorber and the bleacher in the nitric acid plant. The decomposition of HNO2 is a heterogeneous reaction resulting into the formation of nitric acid and desorption of nitric oxide. At high nitric acid concentration (40–50 wt.%), the reversibility of HNO2 decomposition due to NO oxidation with nitric acid is important. The model for bleacher column is presented, which takes into account the de-colorization of the product acid from the absorption column and makes it free from the nitrous acid. The model for the bleacher also takes into account the decomposition and oxidation of HNO2 with dissolved oxygen. The models proposed for absorber and bleacher are validated from the data collected from a mono-pressure nitric acid plant as well as the data present in open literature. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X7R86W-1&_user=6 [...]

Influence of microwave irradiation on a polyesterification reaction / M. Komorowska in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 859-866 Titre : Influence of microwave irradiation on a polyesterification reaction Type de document : texte imprimé Auteurs : M. Komorowska, Auteur ; G.D. Stefanidis, Auteur ; T. Van Gerven, Auteur Année de publication : 2010 Article en page(s) : pp. 859-866 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Microwaves  Heat  transfer  Polyesterification  Efficiency  Multimode  cavity Index. décimale : 660 Résumé : The paper focuses on selective microwave heating and its influence on a polyesterification process. As a model reaction, the polyesterification reaction of adipic acid with neopentyl glycol is investigated. Non-catalyzed and tin (II) chloride catalyzed reaction experiments have been performed with microwave and conventional heating in an open, stirred vessel under a nitrogen atmosphere. Except faster heating times obtained under microwave heating, no different effects on the polyesterification reaction were found between the two heating modes. After 3-h experiments the conversion of the acid groups was similar under microwave heating and conventional heating. Particular emphasis was given on elucidating the important, though scarcely reported in the microwave literature, issues of energy consumption and efficiency. Approximately 20–30% of the electric energy consumed by the microwave oven is converted to thermal energy in the vessel during (non-reactive) heating of the individual components of the polyesterification process. This fraction drops to not, vert, similar5% in the event of isothermal reaction experiments. A vast amount of energy is lost in the magnetron and the multimode cavity; these losses do not hamper conventional (conductive) heating, which is currently more economical. Finally, different ways of improving the thermal efficiency and thus the economic prospects of microwave technology are discussed. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X9NVBP-5&_user=6 [...] [article] Influence of microwave irradiation on a polyesterification reaction [texte imprimé] / M. Komorowska, Auteur ; G.D. Stefanidis, Auteur ; T. Van Gerven, Auteur . - 2010 . - pp. 859-866. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 859-866 Mots-clés : Microwaves  Heat  transfer  Polyesterification  Efficiency  Multimode  cavity Index. décimale : 660 Résumé : The paper focuses on selective microwave heating and its influence on a polyesterification process. As a model reaction, the polyesterification reaction of adipic acid with neopentyl glycol is investigated. Non-catalyzed and tin (II) chloride catalyzed reaction experiments have been performed with microwave and conventional heating in an open, stirred vessel under a nitrogen atmosphere. Except faster heating times obtained under microwave heating, no different effects on the polyesterification reaction were found between the two heating modes. After 3-h experiments the conversion of the acid groups was similar under microwave heating and conventional heating. Particular emphasis was given on elucidating the important, though scarcely reported in the microwave literature, issues of energy consumption and efficiency. Approximately 20–30% of the electric energy consumed by the microwave oven is converted to thermal energy in the vessel during (non-reactive) heating of the individual components of the polyesterification process. This fraction drops to not, vert, similar5% in the event of isothermal reaction experiments. A vast amount of energy is lost in the magnetron and the multimode cavity; these losses do not hamper conventional (conductive) heating, which is currently more economical. Finally, different ways of improving the thermal efficiency and thus the economic prospects of microwave technology are discussed. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X9NVBP-5&_user=6 [...]

CO2 capture from air via CaO-carbonation using a solar-driven fluidized bed reactor / V. Nikulshina in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 867-873 Titre : CO2 capture from air via CaO-carbonation using a solar-driven fluidized bed reactor : effect of temperature and water vapor concentration Type de document : texte imprimé Auteurs : V. Nikulshina, Auteur ; A. Steinfeld, Auteur Année de publication : 2010 Article en page(s) : pp. 867-873 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : CO2  captur  Air  Carbonation  Kinetics  Solar  energy  Radiation  Fluidized  bed  reactor Index. décimale : 660 Résumé : A two-step thermochemical cyclic process to capture CO2 from atmospheric air via consecutive CaO-carbonation CaCO3-calcination reactions is investigated using concentrated solar energy. A kinetic analysis of the carbonation of CaO with dry and moist air containing 500 ppm CO2 is performed in a fluidized bed solar reactor with particles directly exposed to high-flux thermal irradiation. The CO2 removal capacity was examined in the temperature range 290–390 °C and water vapor concentration range 0–17%. Complete CO2 removal was achieved from a continuous flow of moist air at 390 °C and residence times of less than 1.5 s, while the extent of CaO-carbonation was almost doubled by the addition of water vapor. Kinetic models that account for consecutive chemically and diffusion-controlled regimes were applied to describe the carbonation rate with dry air, limited initially through interface reactions and later through reactant penetration across the layer of CaCO3 until reaching the unreacted core. In contrast, a chemically-controlled rate law was applied to describe the augmented carbonation rate with moist air, which proceeded through the formation of an interface of water and/or OH ions at the solid surface not covered by CaCO3. The corresponding reaction orders and Arrhenius rate constants were determined by fitting to the experimental data. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4XF840K-5&_user=6 [...] [article] CO2 capture from air via CaO-carbonation using a solar-driven fluidized bed reactor : effect of temperature and water vapor concentration [texte imprimé] / V. Nikulshina, Auteur ; A. Steinfeld, Auteur . - 2010 . - pp. 867-873. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 867-873 Mots-clés : CO2  captur  Air  Carbonation  Kinetics  Solar  energy  Radiation  Fluidized  bed  reactor Index. décimale : 660 Résumé : A two-step thermochemical cyclic process to capture CO2 from atmospheric air via consecutive CaO-carbonation CaCO3-calcination reactions is investigated using concentrated solar energy. A kinetic analysis of the carbonation of CaO with dry and moist air containing 500 ppm CO2 is performed in a fluidized bed solar reactor with particles directly exposed to high-flux thermal irradiation. The CO2 removal capacity was examined in the temperature range 290–390 °C and water vapor concentration range 0–17%. Complete CO2 removal was achieved from a continuous flow of moist air at 390 °C and residence times of less than 1.5 s, while the extent of CaO-carbonation was almost doubled by the addition of water vapor. Kinetic models that account for consecutive chemically and diffusion-controlled regimes were applied to describe the carbonation rate with dry air, limited initially through interface reactions and later through reactant penetration across the layer of CaCO3 until reaching the unreacted core. In contrast, a chemically-controlled rate law was applied to describe the augmented carbonation rate with moist air, which proceeded through the formation of an interface of water and/or OH ions at the solid surface not covered by CaCO3. The corresponding reaction orders and Arrhenius rate constants were determined by fitting to the experimental data. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4XF840K-5&_user=6 [...]

Plasma-catalytic reforming of methane in AC microsized gliding arc discharge / Nongnuch Rueangjitt in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 874-880 Titre : Plasma-catalytic reforming of methane in AC microsized gliding arc discharge : effects of input power, reactor thickness, and catalyst existence Type de document : texte imprimé Auteurs : Nongnuch Rueangjitt, Auteur ; Thammanoon Sreethawong, Auteur ; Sumaeth Chavadej, Auteur Année de publication : 2010 Article en page(s) : pp. 874-880 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Non-thermal  plasma  Gliding  arc  discharge  Microreactor  Methane  conversion Index. décimale : 660 Résumé : A new design of a microsized gliding arc discharge reactor was preliminarily investigated for the reforming of methane to various useful products. In methane reforming by the gliding arc (GA) microreactor under ambient conditions, hydrogen and acetylene were dominantly produced, with high selectivities of not, vert, similar75% and not, vert, similar70–90%, respectively, which were much higher than those in conventional GA reactors because of the high power density and the extremely short residence time of the GA microreactor, as compared to conventional GA reactors. Small amounts of other products (including ethylene, ethane, butadiene, and coke) were also formed. The results showed that the methane conversion strongly depended on input power and reactor thickness. A Ni-loaded porous alumina-silica catalyst, prepared by wet impregnation, was used to investigate the catalytic effect on the microreactor performance for methane reforming. A considerable enhancement of methane conversion, but not hydrogen and other product selectivities, was achieved in the combined plasma-catalytic system. Furthermore, heating the surface of the Ni-loaded catalyst brought about a significant change in product selectivity, but not methane conversion. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4XF840K-9&_user=6 [...] [article] Plasma-catalytic reforming of methane in AC microsized gliding arc discharge : effects of input power, reactor thickness, and catalyst existence [texte imprimé] / Nongnuch Rueangjitt, Auteur ; Thammanoon Sreethawong, Auteur ; Sumaeth Chavadej, Auteur . - 2010 . - pp. 874-880. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 874-880 Mots-clés : Non-thermal  plasma  Gliding  arc  discharge  Microreactor  Methane  conversion Index. décimale : 660 Résumé : A new design of a microsized gliding arc discharge reactor was preliminarily investigated for the reforming of methane to various useful products. In methane reforming by the gliding arc (GA) microreactor under ambient conditions, hydrogen and acetylene were dominantly produced, with high selectivities of not, vert, similar75% and not, vert, similar70–90%, respectively, which were much higher than those in conventional GA reactors because of the high power density and the extremely short residence time of the GA microreactor, as compared to conventional GA reactors. Small amounts of other products (including ethylene, ethane, butadiene, and coke) were also formed. The results showed that the methane conversion strongly depended on input power and reactor thickness. A Ni-loaded porous alumina-silica catalyst, prepared by wet impregnation, was used to investigate the catalytic effect on the microreactor performance for methane reforming. A considerable enhancement of methane conversion, but not hydrogen and other product selectivities, was achieved in the combined plasma-catalytic system. Furthermore, heating the surface of the Ni-loaded catalyst brought about a significant change in product selectivity, but not methane conversion. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4XF840K-9&_user=6 [...]

Facile preparation of pure CaAl-layered double hydroxides and their application as a hardening accelerator in concrete / Sailong Xu in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 881-885 Titre : Facile preparation of pure CaAl-layered double hydroxides and their application as a hardening accelerator in concrete Type de document : texte imprimé Auteurs : Sailong Xu, Auteur ; Zhanrui Chen, Auteur ; Bowen Zhang, Auteur Année de publication : 2010 Article en page(s) : pp. 881-885 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Layered  double  hydroxides  Separate  nucleation  and  aging  steps  Concrete  Hardening  accelerator  Compressive  and  flexural  strength Index. décimale : 660 Résumé : CaAl-layered double hydroxide (CaAl-LDH), one of anionic functional layered materials, has recently been proposed as potential concrete hardening accelerators. Previous laboratory synthesis shows the necessity of employing a protective nitrogen atmosphere to avoid the formation of large amounts of CaCO3 byproduct. Here, we present a preparation of pure CaAl-LDHs which are readily free of contamination by CaCO3. The CaAl-LDHs were prepared via a scalable method of separate nucleation and aging steps (SNAS) by facile introduction of a mixed ethanol/water media. The application of the as-prepared CaAl-LDHs was investigated as a hardening accelerator in concrete. Standard tests of the compressive and flexural strengths of the cement mortars showed that specimens containing CaAl-LDHs as a hardening accelerator exhibited a greatly enhanced performance in respect of early compressive strength and early flexural strength; and the values increased by 61% and 71%, respectively compared to the pristine concrete specimen. The enhanced performances were addressed in terms of the results in situ X-ray diffraction, scanning electron microscopy, and mercury intrusion porosimetry. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X1J78N-2&_user=6 [...] [article] Facile preparation of pure CaAl-layered double hydroxides and their application as a hardening accelerator in concrete [texte imprimé] / Sailong Xu, Auteur ; Zhanrui Chen, Auteur ; Bowen Zhang, Auteur . - 2010 . - pp. 881-885. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 881-885 Mots-clés : Layered  double  hydroxides  Separate  nucleation  and  aging  steps  Concrete  Hardening  accelerator  Compressive  and  flexural  strength Index. décimale : 660 Résumé : CaAl-layered double hydroxide (CaAl-LDH), one of anionic functional layered materials, has recently been proposed as potential concrete hardening accelerators. Previous laboratory synthesis shows the necessity of employing a protective nitrogen atmosphere to avoid the formation of large amounts of CaCO3 byproduct. Here, we present a preparation of pure CaAl-LDHs which are readily free of contamination by CaCO3. The CaAl-LDHs were prepared via a scalable method of separate nucleation and aging steps (SNAS) by facile introduction of a mixed ethanol/water media. The application of the as-prepared CaAl-LDHs was investigated as a hardening accelerator in concrete. Standard tests of the compressive and flexural strengths of the cement mortars showed that specimens containing CaAl-LDHs as a hardening accelerator exhibited a greatly enhanced performance in respect of early compressive strength and early flexural strength; and the values increased by 61% and 71%, respectively compared to the pristine concrete specimen. The enhanced performances were addressed in terms of the results in situ X-ray diffraction, scanning electron microscopy, and mercury intrusion porosimetry. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X1J78N-2&_user=6 [...]

A facile green extracellular biosynthesis of CdS nanoparticles by immobilized fungus / Rashmi Sanghi in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 886-891 Titre : A facile green extracellular biosynthesis of CdS nanoparticles by immobilized fungus Type de document : texte imprimé Auteurs : Rashmi Sanghi, Auteur ; Preeti Verma, Auteur Année de publication : 2010 Article en page(s) : pp. 886-891 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Fungus  Cadmium  sulfide  nanoparticles  Protein  UV–vis Index. décimale : 660 Résumé : A novel “green” route to prepare CdS nanoparticles under ambient conditions is reported. The long-term studies were carried out with immobilized fungus Coriolus versicolor in continuous column mode. The immobilized fungus served a dual purpose of both bioremediating cadmium as well as synthesizing stable CdS nanoparticles in aqueous conditions. The fungus immobilized in the column could remove 98% cadmium within 2 h. The continuous and extracelluar production of autocapped CdS nanoparticles is an added advantage of this system. Interestingly, no external source of sulfur is required for the transformation of toxic Cd to non-toxic CdS. The thiol group of the fungal protein was found mainly responsible for the production of such highly stable and autocapped CdS nanoparticles. The physico-chemical properties of the particles were studied by FTIR, XRD, SEM, TEM, AFM, TGA and PL. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X1SBK5-2&_user=6 [...] [article] A facile green extracellular biosynthesis of CdS nanoparticles by immobilized fungus [texte imprimé] / Rashmi Sanghi, Auteur ; Preeti Verma, Auteur . - 2010 . - pp. 886-891. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 886-891 Mots-clés : Fungus  Cadmium  sulfide  nanoparticles  Protein  UV–vis Index. décimale : 660 Résumé : A novel “green” route to prepare CdS nanoparticles under ambient conditions is reported. The long-term studies were carried out with immobilized fungus Coriolus versicolor in continuous column mode. The immobilized fungus served a dual purpose of both bioremediating cadmium as well as synthesizing stable CdS nanoparticles in aqueous conditions. The fungus immobilized in the column could remove 98% cadmium within 2 h. The continuous and extracelluar production of autocapped CdS nanoparticles is an added advantage of this system. Interestingly, no external source of sulfur is required for the transformation of toxic Cd to non-toxic CdS. The thiol group of the fungal protein was found mainly responsible for the production of such highly stable and autocapped CdS nanoparticles. The physico-chemical properties of the particles were studied by FTIR, XRD, SEM, TEM, AFM, TGA and PL. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X1SBK5-2&_user=6 [...]

Multifunctional slow-release urea fertilizer from ethylcellulose and superabsorbent coated formulations / Boli Ni in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 892-898 Titre : Multifunctional slow-release urea fertilizer from ethylcellulose and superabsorbent coated formulations Type de document : texte imprimé Auteurs : Boli Ni, Auteur ; Mingzhu Liu, Auteur ; Shaoyu Lu, Auteur Année de publication : 2010 Article en page(s) : pp. 892-898 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Urea  fertilizer  Ethylcellulose  Slow-release  Water-retention  Biodegradation Index. décimale : 660 Résumé : The aim of this study was to prepare a double-coated, slow-release, and water-retention urea fertilizer (DSWU) to reduce environment pollution derived from excessive nitrogen fertilizer use. Ethylcellulose (EC) and crosslinked poly(acrylic acid-co-acrylamide) (P(AA-co-AM)) were used as inner and outer coating materials, respectively. The structural and chemical characteristics of the product, as well as its efficiency in slowing the nitrogen release and water evaporation in soil were examined. The nitrogen content of the product was 21.1% and its water absorbency was 70 times its own weight in tap water. Additionally, the biodegradation of EC coating in soil was assessed by differential scanning calorimetry (DSC) measurements. The results showed that the glass transition temperature (Tg) of EC coating decreased with the time prolonged, which indicated the biodegradability of EC coating in soil. These studies showed that the product with good slow-release and water-retention properties, being environmentally friendly, would find good application in agriculture and horticulture. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X49YKT-7&_user=6 [...] [article] Multifunctional slow-release urea fertilizer from ethylcellulose and superabsorbent coated formulations [texte imprimé] / Boli Ni, Auteur ; Mingzhu Liu, Auteur ; Shaoyu Lu, Auteur . - 2010 . - pp. 892-898. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 892-898 Mots-clés : Urea  fertilizer  Ethylcellulose  Slow-release  Water-retention  Biodegradation Index. décimale : 660 Résumé : The aim of this study was to prepare a double-coated, slow-release, and water-retention urea fertilizer (DSWU) to reduce environment pollution derived from excessive nitrogen fertilizer use. Ethylcellulose (EC) and crosslinked poly(acrylic acid-co-acrylamide) (P(AA-co-AM)) were used as inner and outer coating materials, respectively. The structural and chemical characteristics of the product, as well as its efficiency in slowing the nitrogen release and water evaporation in soil were examined. The nitrogen content of the product was 21.1% and its water absorbency was 70 times its own weight in tap water. Additionally, the biodegradation of EC coating in soil was assessed by differential scanning calorimetry (DSC) measurements. The results showed that the glass transition temperature (Tg) of EC coating decreased with the time prolonged, which indicated the biodegradability of EC coating in soil. These studies showed that the product with good slow-release and water-retention properties, being environmentally friendly, would find good application in agriculture and horticulture. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X49YKT-7&_user=6 [...]

Preparation, characterization and thermal properties of lauric acid/expanded perlite as novel form-stable composite phase change material / Ahmet Sari in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 899-904 Titre : Preparation, characterization and thermal properties of lauric acid/expanded perlite as novel form-stable composite phase change material Type de document : texte imprimé Auteurs : Ahmet Sari, Auteur ; Ali Karaipekli, Auteur ; Cemil Alkan, Auteur Année de publication : 2010 Article en page(s) : pp. 899-904 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Lauric  acid  EP  Form-stable  composite  PCM  Thermal  properties Index. décimale : 660 Résumé : This paper mainly includes the preparation of a novel form-stable composite phase change material (PCM) by incorporation of lauric acid (LA) within the expanded perlite (EP), characterization of the composite by SEM and FT-IR techniques and determination of thermal properties and thermal reliability of the composite PCM using DSC analysis. The LA could be retained by 60 wt.% into EP without melted PCM seepage from the composite and therefore, this composite was described as form-stable composite PCM. SEM results showed that the LA confined into porous of EP. FT-IR analysis indicated that the composite formation of porous EP and LA was physical. The melting and freezing temperatures and latent heats of the composite were measured as 44.13 °C and 40.97 °C; 93.36 J/g and 94.87 J/g, respectively, by DSC analysis. Thermal cycling test showed that the form-stable composite PCM has good thermal reliability and chemical stability although it was subjected to 1000 melting/freezing cycling. Besides, thermal conductivity of the composite PCM was increased approximately as 86% by adding 10 wt.% expanded graphite (EG). As a result, this composite PCM could be considered to have good potential for thermal energy storage because of its good thermal energy storage properties, thermal and chemical reliability and thermal conductivity. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X5JSX8-1&_user=6 [...] [article] Preparation, characterization and thermal properties of lauric acid/expanded perlite as novel form-stable composite phase change material [texte imprimé] / Ahmet Sari, Auteur ; Ali Karaipekli, Auteur ; Cemil Alkan, Auteur . - 2010 . - pp. 899-904. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 899-904 Mots-clés : Lauric  acid  EP  Form-stable  composite  PCM  Thermal  properties Index. décimale : 660 Résumé : This paper mainly includes the preparation of a novel form-stable composite phase change material (PCM) by incorporation of lauric acid (LA) within the expanded perlite (EP), characterization of the composite by SEM and FT-IR techniques and determination of thermal properties and thermal reliability of the composite PCM using DSC analysis. The LA could be retained by 60 wt.% into EP without melted PCM seepage from the composite and therefore, this composite was described as form-stable composite PCM. SEM results showed that the LA confined into porous of EP. FT-IR analysis indicated that the composite formation of porous EP and LA was physical. The melting and freezing temperatures and latent heats of the composite were measured as 44.13 °C and 40.97 °C; 93.36 J/g and 94.87 J/g, respectively, by DSC analysis. Thermal cycling test showed that the form-stable composite PCM has good thermal reliability and chemical stability although it was subjected to 1000 melting/freezing cycling. Besides, thermal conductivity of the composite PCM was increased approximately as 86% by adding 10 wt.% expanded graphite (EG). As a result, this composite PCM could be considered to have good potential for thermal energy storage because of its good thermal energy storage properties, thermal and chemical reliability and thermal conductivity. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X5JSX8-1&_user=6 [...]

High-efficient microwave synthesis and characterisation of SrSnO3 / Imberger, Jörg in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 905-909 Titre : High-efficient microwave synthesis and characterisation of SrSnO3 Type de document : texte imprimé Auteurs : Imberger, Jörg, Auteur ; Rafael Libanori, Auteur ; Mario L. Moreira, Auteur Année de publication : 2010 Article en page(s) : pp. 905-909 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : SrSnO3  Microwave  Nanostructures  Photoluminescence Index. décimale : 660 Résumé : Strontium stannate (SrSnO3) nanostructures were obtained by microwave-assisted calcination of a SrSn(OH)6 precursor powder. Compared to other conventional calcination methods mentioned in the literature, this procedure led to a remarkable decrease of the reaction time and the synthesis temperature owing to direct interaction of radiation with the material. X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and photoluminescence measurements were performed. A comparison of the characterisation results obtained by microwave and conventional methods was conducted, and differences concerning the properties of conventionally high-temperature calcined SrSnO3 from that obtained by microwave-assisted calcination were observed. Furthermore, two different morphologies (nanosticks and nanobrushes) were obtained by a variation of the concentration of the reactants. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X5JSX8-2&_user=6 [...] [article] High-efficient microwave synthesis and characterisation of SrSnO3 [texte imprimé] / Imberger, Jörg, Auteur ; Rafael Libanori, Auteur ; Mario L. Moreira, Auteur . - 2010 . - pp. 905-909. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 905-909 Mots-clés : SrSnO3  Microwave  Nanostructures  Photoluminescence Index. décimale : 660 Résumé : Strontium stannate (SrSnO3) nanostructures were obtained by microwave-assisted calcination of a SrSn(OH)6 precursor powder. Compared to other conventional calcination methods mentioned in the literature, this procedure led to a remarkable decrease of the reaction time and the synthesis temperature owing to direct interaction of radiation with the material. X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and photoluminescence measurements were performed. A comparison of the characterisation results obtained by microwave and conventional methods was conducted, and differences concerning the properties of conventionally high-temperature calcined SrSnO3 from that obtained by microwave-assisted calcination were observed. Furthermore, two different morphologies (nanosticks and nanobrushes) were obtained by a variation of the concentration of the reactants. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X5JSX8-2&_user=6 [...]

Zinc oxide nanostructures derived from a simple solution method for solar cells and LEDs / Periyayya Uthirakumar in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 910-915 Titre : Zinc oxide nanostructures derived from a simple solution method for solar cells and LEDs Type de document : texte imprimé Auteurs : Periyayya Uthirakumar, Auteur ; Hyung Gu Kim, Auteur ; Chang-Hee Hong, Auteur Année de publication : 2010 Article en page(s) : pp. 910-915 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Oxides  Nanostructures  Chemical  synthesis  Electron  microscopy  Solar  cells Index. décimale : 660 Résumé : A simple solution method has been proposed that deals the specific impacts of solvent characteristics on the growth of zinc oxide (ZnO) nanoparticles. The aggregation of particles is a major drawback in the hydrothermal method, and it is suppressed by using a less polar reaction solvent. ZnO particles obtained from a lower polarity indexed reaction medium show a very strong UV band-edge emission with an almost negligible deep level emission when compared to ZnO particles isolated from the higher polarity index of the medium. For the application is concerned, highly dispersible ZnO nanomaterials are used as an active material for dye-sensitized solar cells (DSSC), due to their higher internal surface area. Additionally, the deposition of ZnO layers on commercially available GaN-based blue light emitting diodes (LEDs) is fabricated to improve the light extraction efficiency, without disturbing the basic structure of the LED. The layer thickness and light transmission at a specific wavelength are the major factors which can improve the light emission from LEDs. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X9NVBP-3&_user=6 [...] [article] Zinc oxide nanostructures derived from a simple solution method for solar cells and LEDs [texte imprimé] / Periyayya Uthirakumar, Auteur ; Hyung Gu Kim, Auteur ; Chang-Hee Hong, Auteur . - 2010 . - pp. 910-915. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 910-915 Mots-clés : Oxides  Nanostructures  Chemical  synthesis  Electron  microscopy  Solar  cells Index. décimale : 660 Résumé : A simple solution method has been proposed that deals the specific impacts of solvent characteristics on the growth of zinc oxide (ZnO) nanoparticles. The aggregation of particles is a major drawback in the hydrothermal method, and it is suppressed by using a less polar reaction solvent. ZnO particles obtained from a lower polarity indexed reaction medium show a very strong UV band-edge emission with an almost negligible deep level emission when compared to ZnO particles isolated from the higher polarity index of the medium. For the application is concerned, highly dispersible ZnO nanomaterials are used as an active material for dye-sensitized solar cells (DSSC), due to their higher internal surface area. Additionally, the deposition of ZnO layers on commercially available GaN-based blue light emitting diodes (LEDs) is fabricated to improve the light extraction efficiency, without disturbing the basic structure of the LED. The layer thickness and light transmission at a specific wavelength are the major factors which can improve the light emission from LEDs. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X9NVBP-3&_user=6 [...]

Preparation of mesoporous silica with grafted chelating agents for uptake of metal ions / Zeid A. Alothman in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 916-924 Titre : Preparation of mesoporous silica with grafted chelating agents for uptake of metal ions Type de document : texte imprimé Auteurs : Zeid A. Alothman, Auteur ; Allen W. Apblett, Auteur Année de publication : 2010 Article en page(s) : pp. 916-924 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Mesoporous  silica  TEOS  GPTMS  29Si  NMR  Copper Index. décimale : 660 Résumé : Functionalized hexagonal mesoporous silicas were prepared by chemical modifcation of a surfactant free mesoporous silica (OSU-6-W) with 3-glycidoxypropyltrimethoxysilane. Different degrees of derivitization with 3-glycidoxypropyl were realized by using either a single silylation reaction or two silylation reactions with an intermediate hydrolysis step. The two resulting inorganic–organic hybrids were characterized by solid-state 29Si nuclear magnetic resonance (NMR) spectroscopy, a titration method, and elemental analysis of the modified samples and the average numbers of pendant groups were found to be 2.17 and 3.49 groups/nm2, respectively. Surface area analysis showed that these materials have pore diameters of 40.7 and 33.2 Å and surface areas of 966 and 720 m2/g, respectively. Infrared spectroscopy, solid-state NMR for 13C and 29Si nuclei and X-ray diffraction patterns are in agreement with the success of the preparation of organically modified mesoporous silicas. The basic centers of the attached pendant groups provide the capacity to extract copper from aqueous solution via an adsorption process that followed the Langmuir model and had a remarkably high capacity of 6.75 mmol g−1 for adsorption of copper. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X9NVBP-6&_user=6 [...] [article] Preparation of mesoporous silica with grafted chelating agents for uptake of metal ions [texte imprimé] / Zeid A. Alothman, Auteur ; Allen W. Apblett, Auteur . - 2010 . - pp. 916-924. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 916-924 Mots-clés : Mesoporous  silica  TEOS  GPTMS  29Si  NMR  Copper Index. décimale : 660 Résumé : Functionalized hexagonal mesoporous silicas were prepared by chemical modifcation of a surfactant free mesoporous silica (OSU-6-W) with 3-glycidoxypropyltrimethoxysilane. Different degrees of derivitization with 3-glycidoxypropyl were realized by using either a single silylation reaction or two silylation reactions with an intermediate hydrolysis step. The two resulting inorganic–organic hybrids were characterized by solid-state 29Si nuclear magnetic resonance (NMR) spectroscopy, a titration method, and elemental analysis of the modified samples and the average numbers of pendant groups were found to be 2.17 and 3.49 groups/nm2, respectively. Surface area analysis showed that these materials have pore diameters of 40.7 and 33.2 Å and surface areas of 966 and 720 m2/g, respectively. Infrared spectroscopy, solid-state NMR for 13C and 29Si nuclei and X-ray diffraction patterns are in agreement with the success of the preparation of organically modified mesoporous silicas. The basic centers of the attached pendant groups provide the capacity to extract copper from aqueous solution via an adsorption process that followed the Langmuir model and had a remarkably high capacity of 6.75 mmol g−1 for adsorption of copper. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X9NVBP-6&_user=6 [...]

Surfactant assisted hydrothermal and thermal decomposition synthesis of alumina microfibers with mesoporous structure / Zhenfeng Zhu in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 925-930 Titre : Surfactant assisted hydrothermal and thermal decomposition synthesis of alumina microfibers with mesoporous structure Type de document : texte imprimé Auteurs : Zhenfeng Zhu, Auteur ; Hui Liu, Auteur ; Hongjun Sun, Auteur Année de publication : 2010 Article en page(s) : pp. 925-930 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Mesoporous  alumina  Microfibers  Hydrothermal  synthesis  SCR-NH3  of  NO Index. décimale : 660 Résumé : The alumina microfibers with mesoporous structure were synthesized by a facile hydrothermal and thermal decomposition route. The as-obtained products were well characterized by XRD, SEM, TEM (HRTEM), SAED and N2 adsorption–desorption measurement. It was shown that the length and diameter of these alumina microfibers are about 10 μm and 300–500 nm, respectively. All these alumina microfibers prepared by the PEG templates with different molecular weight have the different high surface area but nearly the same pore diameter about 3.5 nm. The calcination experimental result shows that the mesoporosity of these alumina microfibers can be maintained even at 1373 K. On the other hand, the higher selective catalytic reduction (SCR) of NO effectiveness present that the as-obtained mesoporous alumina have stronger adsorption property because of its high surface area. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X9NVBP-4&_user=6 [...] [article] Surfactant assisted hydrothermal and thermal decomposition synthesis of alumina microfibers with mesoporous structure [texte imprimé] / Zhenfeng Zhu, Auteur ; Hui Liu, Auteur ; Hongjun Sun, Auteur . - 2010 . - pp. 925-930. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 925-930 Mots-clés : Mesoporous  alumina  Microfibers  Hydrothermal  synthesis  SCR-NH3  of  NO Index. décimale : 660 Résumé : The alumina microfibers with mesoporous structure were synthesized by a facile hydrothermal and thermal decomposition route. The as-obtained products were well characterized by XRD, SEM, TEM (HRTEM), SAED and N2 adsorption–desorption measurement. It was shown that the length and diameter of these alumina microfibers are about 10 μm and 300–500 nm, respectively. All these alumina microfibers prepared by the PEG templates with different molecular weight have the different high surface area but nearly the same pore diameter about 3.5 nm. The calcination experimental result shows that the mesoporosity of these alumina microfibers can be maintained even at 1373 K. On the other hand, the higher selective catalytic reduction (SCR) of NO effectiveness present that the as-obtained mesoporous alumina have stronger adsorption property because of its high surface area. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X9NVBP-4&_user=6 [...]

Influence of the activation conditions on the porosity development of herringbone carbon nanofibers / Vicente Jiménez in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 931-940 Titre : Influence of the activation conditions on the porosity development of herringbone carbon nanofibers Type de document : texte imprimé Auteurs : Vicente Jiménez, Auteur ; José Antonio Díaz, Auteur ; Paula Sánchez, Auteur Année de publication : 2010 Article en page(s) : pp. 931-940 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Carbon  nanofibers  Activation  Porosity  Carbon  yield  Adsorption Index. décimale : 660 Résumé : The influence of different activation conditions, including activating agent/CNFs mass ratio, activation temperature, activation time and He flow rate, on the pore structure development of herringbone carbon nanofibers (CNFs) has been studied. Activation conditions with a KOH/CNFs mass ratio = 5/1, activation temperature = 850 °C, activation time = 3 h and He flow rate = 700 mL min−1 gave rise to a material with a very high micropore volume, a quite narrow micropore distribution and the highest surface area (increased by a factor of 4.5 in comparison to the raw CNFs). The conditions outlined above also led to the creation of some mesopores in the activation process due to the strong interaction between the CNFs and the activating agent. On the other hand, the use of other activation conditions led to activated CNFs with different structural properties. For example, activated CNFs with the lowest mesopore volume were obtained when the activation conditions were KOH/CNFs mass ratio = 5/1, activation temperature = 900 °C, activation time = 3 h and He flow rate = 500 mL min−1. Therefore, depending on the final application of the activated CNFs, it is possible to control their pore structure by selecting appropriate activation conditions. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X9NVBP-C&_user=6 [...] [article] Influence of the activation conditions on the porosity development of herringbone carbon nanofibers [texte imprimé] / Vicente Jiménez, Auteur ; José Antonio Díaz, Auteur ; Paula Sánchez, Auteur . - 2010 . - pp. 931-940. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 931-940 Mots-clés : Carbon  nanofibers  Activation  Porosity  Carbon  yield  Adsorption Index. décimale : 660 Résumé : The influence of different activation conditions, including activating agent/CNFs mass ratio, activation temperature, activation time and He flow rate, on the pore structure development of herringbone carbon nanofibers (CNFs) has been studied. Activation conditions with a KOH/CNFs mass ratio = 5/1, activation temperature = 850 °C, activation time = 3 h and He flow rate = 700 mL min−1 gave rise to a material with a very high micropore volume, a quite narrow micropore distribution and the highest surface area (increased by a factor of 4.5 in comparison to the raw CNFs). The conditions outlined above also led to the creation of some mesopores in the activation process due to the strong interaction between the CNFs and the activating agent. On the other hand, the use of other activation conditions led to activated CNFs with different structural properties. For example, activated CNFs with the lowest mesopore volume were obtained when the activation conditions were KOH/CNFs mass ratio = 5/1, activation temperature = 900 °C, activation time = 3 h and He flow rate = 500 mL min−1. Therefore, depending on the final application of the activated CNFs, it is possible to control their pore structure by selecting appropriate activation conditions. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X9NVBP-C&_user=6 [...]

Hydrogenation of sunflower oil over different palladium supported catalysts / Maria B. Fernàndez in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 941-949 Titre : Hydrogenation of sunflower oil over different palladium supported catalysts : activity and selectivity Type de document : texte imprimé Auteurs : Maria B. Fernàndez, Auteur ; Jhon F. Sánchez M., Auteur ; Tonetto, Gabriela M., Auteur Année de publication : 2010 Article en page(s) : pp. 941-949 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Hydrogenation  Isomerization  Palladium  Sunflower  oil  Trans-isomers Index. décimale : 660 Résumé : Six palladium catalysts were prepared using different precursors (palladium acetylacetonate, palladium nitrate and tetraamminepalladium nitrate) and supports (α-Al2O3, γ-Al2O3, ZSM-5, and MCM-22). The samples were characterized by atomic absorption spectroscopy, N2 adsorption isotherms, XRD, H2 chemisorption, transmission electron microscopy and temperature programmed reduction. The activity and selectivity of the catalysts were investigated in the hydrogenation of sunflower oil and compared to a commercial Ni catalyst. Pd catalysts showed a higher activity, similar trans-isomer formation, and were more selective towards monoene formation than Ni catalysts. On the other hand, under the studied operating conditions, the different supports did not improve significantly the selectivity or the activity of the reaction. The γ-alumina supported Pd catalyst, with a metal loading of 0.78 wt% and a 60% dispersion, showed a specific activity higher than the other Pd catalysts. For the same double bond conversion, this sample originated a slightly lower amount of total trans-isomers than the Ni catalyst, but it produced less saturated compound and was more selective towards monounsaturated fatty acid formation. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4XB79WP-2&_user=6 [...] [article] Hydrogenation of sunflower oil over different palladium supported catalysts : activity and selectivity [texte imprimé] / Maria B. Fernàndez, Auteur ; Jhon F. Sánchez M., Auteur ; Tonetto, Gabriela M., Auteur . - 2010 . - pp. 941-949. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 941-949 Mots-clés : Hydrogenation  Isomerization  Palladium  Sunflower  oil  Trans-isomers Index. décimale : 660 Résumé : Six palladium catalysts were prepared using different precursors (palladium acetylacetonate, palladium nitrate and tetraamminepalladium nitrate) and supports (α-Al2O3, γ-Al2O3, ZSM-5, and MCM-22). The samples were characterized by atomic absorption spectroscopy, N2 adsorption isotherms, XRD, H2 chemisorption, transmission electron microscopy and temperature programmed reduction. The activity and selectivity of the catalysts were investigated in the hydrogenation of sunflower oil and compared to a commercial Ni catalyst. Pd catalysts showed a higher activity, similar trans-isomer formation, and were more selective towards monoene formation than Ni catalysts. On the other hand, under the studied operating conditions, the different supports did not improve significantly the selectivity or the activity of the reaction. The γ-alumina supported Pd catalyst, with a metal loading of 0.78 wt% and a 60% dispersion, showed a specific activity higher than the other Pd catalysts. For the same double bond conversion, this sample originated a slightly lower amount of total trans-isomers than the Ni catalyst, but it produced less saturated compound and was more selective towards monounsaturated fatty acid formation. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4XB79WP-2&_user=6 [...]