The Experts below are selected from a list of 10182 Experts worldwide ranked by ideXlab platform
J. François - One of the best experts on this subject based on the ideXlab platform.
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Chromium Removal using modified poly(4-vinylpyridinium) bentonite salts
Desalination, 2009Co-Authors: Ali Mansri, Kamel Ismet Benabadji, J. Desbrières, J. FrançoisAbstract:A new composite material able to remove hexavalent Chromium [Cr(VI)] ions from aqueous solutions was obtained by reacting poly(4-vinylpyridine) (P4VP) with bentonite clay [Bf]. Two composite samples, Bf0.06 and Bf0.3, were prepared by varying initial amounts of P4VP. Thermogravimetric analysis revealed good stability of the new materials at high temperatures. FTIR technique clearly showed that P4VP was adsorbed on bentonite. The good efficiency in removing Chromium ions from acidic solutions was demonstrated by adsorption kinetics. Freundlich and Langmuir isotherm models were used to determine adsorption capacity of Bf, Bf0.06 and Bf0.3 composites at 25°C and at pH = 1. The specific role of P4VP salt in the new composite materials was evaluated by comparing the kinetics of the original bentonite and polymer-modified composites. The obtained results showed clearly that the pyridinium positive charges on the polymer were efficient in hexavalent Chromium Removal from aqueous solutions. The thermodynamics of the rate processes showed the adsorption of Chromium ions to be endothermic, accompanied by decreases in Gibbs free energy. The results showed the potentiality of these composites as an adsorbent for Chromium ions from aqueous solutions.
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Chromium Removal using modified poly(4-vinylpyridinium) bentonite salts
Desalination, 2009Co-Authors: Ali Mansri, Kamel Ismet Benabadji, J. Desbrières, J. FrançoisAbstract:cited By 33International audienceA new composite material able to remove hexavalent Chromium [Cr(VI)] ions from aqueous solutions was obtained by reacting poly(4-vinylpyridine) (P4VP) with bentonite clay [Bf]. Two composite samples, Bf0.06 and Bf0.3, were prepared by varying initial amounts of P4VP. Thermogravimetric analysis revealed good stability of the new materials at high temperatures. FTIR technique clearly showed that P4VP was adsorbed on bentonite. The good efficiency in removing Chromium ions from acidic solutions was demonstrated by adsorption kinetics. Freundlich and Langmuir isotherm models were used to determine adsorption capacity of Bf, Bf0.06 and Bf0.3 composites at 25°C and at pH = 1. The specific role of P4VP salt in the new composite materials was evaluated by comparing the kinetics of the original bentonite and polymer-modified composites. The obtained results showed clearly that the pyridinium positive charges on the polymer were efficient in hexavalent Chromium Removal from aqueous solutions. The thermodynamics of the rate processes showed the adsorption of Chromium ions to be endothermic, accompanied by decreases in Gibbs free energy. The results showed the potentiality of these composites as an adsorbent for Chromium ions from aqueous solutions. © 2009
Eliseo Cristiani-urbina - One of the best experts on this subject based on the ideXlab platform.
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Effect of pH on hexavalent and total Chromium Removal from aqueous solutions by avocado shell using batch and continuous systems
Environmental Science and Pollution Research, 2019Co-Authors: Erick Aranda-garcía, Eliseo Cristiani-urbinaAbstract:Solution pH appears to be the most important regulator of the biosorptive Removal of Chromium ions from aqueous solutions. This work presents a kinetic study of the effects of solution pH on Cr(VI) and total Chromium Removal from aqueous solution by Hass avocado shell (HAS) in batch and continuous packed bed column systems. Different Cr(VI) and total Chromium Removal performances of HAS were obtained in pH-shift batch, pH-controlled batch, and continuous systems. These results emphasize the great importance of determining the most appropriate pH for Cr(VI) and total Chromium Removal, considering the operational mode of the proposed large-scale treatment system. Total Chromium biosorption batch kinetics was well described by the Elovich model, whereas in the continuous system, the fitness of the kinetic models to the experimental data was pH dependent. X-ray photoelectron spectroscopy and kinetic studies clearly indicated that the reaction mechanism of Cr(VI) with HAS was the reductive biotransformation of Cr(VI) to Cr(III), which was partially released to the aqueous solution and partially biosorbed onto HAS.
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Effect of pH, ionic strength, and background electrolytes on Cr(VI) and total Chromium Removal by acorn shell of Quercus crassipes Humb. & Bonpl.
Environmental monitoring and assessment, 2014Co-Authors: Erick Aranda-garcía, Liliana Morales-barrera, Gabriela Pineda-camacho, Eliseo Cristiani-urbinaAbstract:The ability of Quercus crassipes acorn shells (QCS) to remove Cr(VI) and total Chromium from aqueous solutions was investigated as a function of the solution pH, ionic strength, and background electrolytes. It was found that Cr(VI) and total Chromium Removal by QCS depended strongly on the pH of the solution. Cr(VI) Removal rate increased as the solution pH decreased. The optimum pH for total Chromium Removal varied depending on contact time. NaCl ionic strengths lower than 200 mM did not affect Chromium Removal. The presence of 20 mM monovalent cations and anions, and of divalent cations, slightly decreased the Removal of Cr(VI) and total Chromium by QCS; in contrast, divalent anions (SO4 2−, PO4 2−, CO3 2−) significantly affected the Removal of Cr(VI) and total Chromium. The biosorption kinetics of Chromium ions followed the pseudo-second-order model at all solution pH levels, NaCl ionic strengths and background electrolytes tested. Results suggest that QCS may be a potential low-cost biosorbent for the Removal of Cr(VI) and total Chromium from aqueous solutions containing various impurities.
Saswati Chakraborty - One of the best experts on this subject based on the ideXlab platform.
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Fixed-bed column study for hexavalent Chromium Removal and recovery by short-chain polyaniline synthesized on jute fiber.
Journal of hazardous materials, 2008Co-Authors: Potsangbam Albino Kumar, Saswati ChakrabortyAbstract:Fixed-bed column studies were conducted to evaluate performance of a short-chain polymer, polyaniline, synthesized on the surface of jute fiber (PANI-jute) for the Removal of hexavalent Chromium [Cr(VI)] in aqueous environment. Influent pH, column bed depth, influent Cr(VI) concentrations and influent flow rate were variable parameters for the present study. Optimum pH for total Chromium Removal was observed as 3 by electrostatic attraction of acid chromate ion (HCrO(4)(-)) with protonated amine group (NH(3)(+)) of PANI-jute. With increase in column bed depth from 40 to 60 cm, total Chromium uptake by PANI-jute increased from 4.14 to 4.66 mg/g with subsequent increase in throughput volume from 9.84 to 12.6L at exhaustion point. The data obtained for total Chromium Removal were well described by BDST equation till 10% breakthrough. Adsorption rate constant and dynamic bed capacity at 10% breakthrough were observed as 0.01 L/mgh and 1069.46 mg/L, respectively. Adsorbed total Chromium was recovered back from PANI-jute as non-toxic Cr(III) after ignition with more than 97% reduction in weight, minimizing the problem of solid waste disposal.
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hexavalent Chromium Removal from wastewater using aniline formaldehyde condensate coated silica gel
Journal of Hazardous Materials, 2007Co-Authors: Albino P Kumar, Saswati ChakrabortyAbstract:Abstract A resinous polymer, aniline formaldehyde condensate (AFC) coated on silica gel was used as an adsorbent in batch system for Removal of hexavalent Chromium from aqueous solution by considering the effects of various parameters like reaction pH, dose of AFC coated silica gel, initial Cr(VI) concentration and aniline to formaldehyde ratio in AFC synthesis. The optimum pH for total Chromium [Cr(VI) and Cr(III)] adsorption was observed as 3. Total Chromium adsorption was second order and equilibrium was achieved within 90–120 min. Aniline to formaldehyde ratio of 1.6:1 during AFC synthesis was ideal for Chromium Removal. Total Chromium adsorption followed Freundlich's isotherm with adsorption capacity of 65 mg/g at initial Cr(VI) 200 mg/L. Total Chromium Removal was explained as combinations of electrostatic attraction of acid chromate ion by protonated AFC, reduction of Cr(VI) to Cr(III) and bond formation of Cr(III) with nitrogen atom of AFC. Almost 40–84% of adsorbed Chromium was recovered during desorption by NaOH, EDTA and mineral acids. AFC coated silica gel can be effectively used for treatment of Chromium containing wastewaters as an alternative.
Ali Mansri - One of the best experts on this subject based on the ideXlab platform.
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Chromium Removal using poly(4-vinylpyridinium)-modified treated clay salts
Desalination and Water Treatment, 2013Co-Authors: Kamel Ismet Benabadji, Ali MansriAbstract:AbstractNew composite materials, able to remove hexavalent Chromium [Cr(VI)] ions from aqueous solutions, were obtained by reacting poly(4-vinylpyridine) (P4VP) with treated clay [TC]. Two composite samples [TCP4VP-5-0.5] and [TCP4VP-5-1.5], were prepared by varying initial amounts of P4VP and TC and characterized. The retention of Cr(VI) was investigated by batch equilibrium procedure. The good efficiency in removing Chromium ions from acidic solutions was demonstrated by adsorption kinetics. Freundlich and Langmuir isotherm models were used to determine adsorption capacity of the TC and of the modified composites [TCP4VP-5-0.5] and [TCP4VP-5-1.5], at 25°C and at pH = 1. The specific role of P4VP salt in new composite materials was evaluated by comparing the kinetics of the TC and [TCP4VP-5-0.5] and [TCP4VP-5-1.5] composites. The obtained results showed clearly that the pyridinium positive charges on the polymer were efficient in hexavalent Chromium Removal from aqueous solutions. The thermodynamics of t...
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Chromium Removal using modified poly(4-vinylpyridinium) bentonite salts
Desalination, 2009Co-Authors: Ali Mansri, Kamel Ismet Benabadji, J. Desbrières, J. FrançoisAbstract:A new composite material able to remove hexavalent Chromium [Cr(VI)] ions from aqueous solutions was obtained by reacting poly(4-vinylpyridine) (P4VP) with bentonite clay [Bf]. Two composite samples, Bf0.06 and Bf0.3, were prepared by varying initial amounts of P4VP. Thermogravimetric analysis revealed good stability of the new materials at high temperatures. FTIR technique clearly showed that P4VP was adsorbed on bentonite. The good efficiency in removing Chromium ions from acidic solutions was demonstrated by adsorption kinetics. Freundlich and Langmuir isotherm models were used to determine adsorption capacity of Bf, Bf0.06 and Bf0.3 composites at 25°C and at pH = 1. The specific role of P4VP salt in the new composite materials was evaluated by comparing the kinetics of the original bentonite and polymer-modified composites. The obtained results showed clearly that the pyridinium positive charges on the polymer were efficient in hexavalent Chromium Removal from aqueous solutions. The thermodynamics of the rate processes showed the adsorption of Chromium ions to be endothermic, accompanied by decreases in Gibbs free energy. The results showed the potentiality of these composites as an adsorbent for Chromium ions from aqueous solutions.
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Chromium Removal using modified poly(4-vinylpyridinium) bentonite salts
Desalination, 2009Co-Authors: Ali Mansri, Kamel Ismet Benabadji, J. Desbrières, J. FrançoisAbstract:cited By 33International audienceA new composite material able to remove hexavalent Chromium [Cr(VI)] ions from aqueous solutions was obtained by reacting poly(4-vinylpyridine) (P4VP) with bentonite clay [Bf]. Two composite samples, Bf0.06 and Bf0.3, were prepared by varying initial amounts of P4VP. Thermogravimetric analysis revealed good stability of the new materials at high temperatures. FTIR technique clearly showed that P4VP was adsorbed on bentonite. The good efficiency in removing Chromium ions from acidic solutions was demonstrated by adsorption kinetics. Freundlich and Langmuir isotherm models were used to determine adsorption capacity of Bf, Bf0.06 and Bf0.3 composites at 25°C and at pH = 1. The specific role of P4VP salt in the new composite materials was evaluated by comparing the kinetics of the original bentonite and polymer-modified composites. The obtained results showed clearly that the pyridinium positive charges on the polymer were efficient in hexavalent Chromium Removal from aqueous solutions. The thermodynamics of the rate processes showed the adsorption of Chromium ions to be endothermic, accompanied by decreases in Gibbs free energy. The results showed the potentiality of these composites as an adsorbent for Chromium ions from aqueous solutions. © 2009
Soumya Elabed - One of the best experts on this subject based on the ideXlab platform.
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Correlation between cell surface physicochemical properties of bacterial strains and their Chromium Removal potential
Journal of Adhesion Science and Technology, 2017Co-Authors: Meryem Asri, Alae Elabed, Nabil Tirry, Aziza Kouchou, Saad Ibnsouda Koraichi, Naïma El Ghachtouli, Soumya ElabedAbstract:AbstractPhysicochemical characterization of microbes has gained recently a great interest by scientific community. It is proved of extreme importance in several fields of science and technology applications such as bioremediation. In this work, we investigated the establishment of a possible correlation between Chromium Removal capacity of seven bacterial strains isolated from contaminated sites with industrial wastes including tanning processing and their cell surface physicochemical properties. Thus, hydrophobicity and donor/acceptor electrons character were obtained using contact angle measurements. Statistical analysis showed a high significant positive correlation between hexavalent Chromium (Cr(VI)) Removal by the strains and their acceptor electron character γ+(r = 0.90). While significant negative correlation between the Cr(VI) Removal potential and the ΔGiwi value (r = −0.844) and also with their donor electron character γ− (r = −0.746) were observed. These results may contribute to determine a s...
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Correlation between cell surface physicochemical properties of bacterial strains and their Chromium Removal potential
Journal of Adhesion Science and Technology, 2017Co-Authors: Meryem Asri, Alae Elabed, Nabil Tirry, Aziza Kouchou, Naïma El Ghachtouli, Saad Ibnsouda Koraichi, Soumya ElabedAbstract:Physicochemical characterization of microbes has gained recently a great interest by scientific community. It is proved of extreme importance in several fields of science and technology applications such as bioremediation. In this work, we investigated the establishment of a possible correlation between Chromium Removal capacity of seven bacterial strains isolated from contaminated sites with industrial wastes including tanning processing and their cell surface physicochemical properties. Thus, hydrophobicity and donor/acceptor electrons character were obtained using contact angle measurements. Statistical analysis showed a high significant positive correlation between hexavalent Chromium (Cr(VI)) Removal by the strains and their acceptor electron character γ+(r = 0.90). While significant negative correlation between the Cr(VI) Removal potential and the ΔGiwi value (r = −0.844) and also with their donor electron character γ− (r = −0.746) were observed. These results may contribute to determine a selectrion criteria of bacteria that can be operated in bioremediation applications.
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Theoretical and experimental adhesion of yeast strains with high Chromium Removal potential
Environmental Engineering Science, 2017Co-Authors: Meryem Asri, Alae Elabed, Saad Ibnsouda Koraichi, Naïma El Ghachtouli, Wifak Bahafid, Soumya ElabedAbstract:Biofilm-based bioprocesses are increasingly used in wastewater treatment. Microbial adhesion constitutes the key step in stability of these depollution systems. For adhesion studies, physicochemical characterization of microbial cells and supports has proved to be of extreme importance. In this work, estimation of interaction between five yeast strains with a high potential for Cr (VI) Removal using extended Derjaguin–Landau–Verwey and Overbeek (XDLVO) theory as a powerful predictive tool of adhesion was investigated. Predictions showed that wood husk could be a good support for the formation of tested yeast biofilm, beech and oak exhibit better properties than other wood species studied with 100% of potential for adhesion. From a thermodynamic point of view, pine and teak woods are not suitable for biofilm formation for all tested yeast strains, presenting positive values of free energy adhesion (ΔGXDLVO). Environmental scanning electronic microscopy (ESEM) and Matlab® image analysis confirmed that all tested yeast strains were able to adhere to pine wood and, except for Wickerhamomyces anomalus they were unable to adhere to oak wood. Adhesion experiments were found to be well related to the theoretical prediction. To our knowledge, this is the first study dealing with biofilm-mediated depollution from an adhesion point of view aiming to optimize the stability of the system. It allows expanding knowledge about adhesion phenomena of yeast strains on wooden surface and contributes to select the best biofilm-support combination that would be used in a performant biological system for Chromium Removal.