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13 results on '"Methylene blue sorption"'

1. The Influence of Pore-Forming Diluents on Porous Structure, Thermal and Sorption Properties of the Divinylbenzene and Glycidyl Methacrylate Copolymers.

Author

Sobiesiak, Magdalena and Parcheta, Monika

Subjects
*CHEMICAL properties, *GLYCIDYL methacrylate, *WATER purification, *METHYLENE blue, *BENZYL alcohol
Abstract

The aim of this work was the characterization of polymer microspheres obtained by the suspension polymerization of divinylbenzene (DVB) and glycidyl methacrylate (GMA), depending on the pore-forming diluents and molar ratio of monomers. The assessed properties included the chemical and porous structure, thermal stability, and sorption capacity of the obtained polymers towards methylene blue. The abovementioned characteristic was carried out for two series of copolymers with molar ratios of monomers of 1:2, 1:1 and 2:1, synthetized with toluene and a mixture of decanol and benzyl alcohol. The structure of the polymers was confirmed by FTIR and elemental analysis. The results of TGA demonstrated the main influence on thermal stability was the composition of polymers, whereas the impact of porogens was negligible. The SBET varied in the range of 12–534 m2g−1 for polymers obtained with toluene and 0–396 m2g−1 with the mixture of alcohols. Toluene enhanced the formation of micro- and mesopores, while the mixture of alcohols enhanced the creation of meso- and macropores. For the polymers prepared with toluene, their effectiveness in water purification decreases in the following order: DVB-GMA 2:1 > DVB-GMA 1:1 > DVB-GMA 1:2, according to the decreasing values of porous structure parameters. In the case of a series obtained with a mixture of alcohols, such correlation was not observed. [ABSTRACT FROM AUTHOR]

Published
2024
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2. Alkali induced changes in spatial distribution of functional groups in carboxymethylated cellulose – comparison of cotton and viscose fibers.

Author

Bogner, Paul, Mahmud-Ali, Amalid, Bechtold, Thomas, Pham, Tung, and Manian, Avinash P.

Subjects
COTTON fibers, CARBOXYL group, VISCOSE, CARBOXYMETHYLATION, FUNCTIONAL groups, METHYLENE blue
Abstract

The aim of the work was to compare the levels of carboxymethylation on cotton with what was obtained previously on viscose fibers under the same treatment conditions. In addition to carboxymethylation levels, their performance was also compared in terms of their propensity for sorption of methylene blue, a cationic dye that is a putative wastewater contaminant. Under comparable conditions of treatment, the degree of carboxymethylation in cotton was 30–90% of that in viscose but the molar ratio of dye sorption to carboxyl groups was 100–230% of that in viscose. In other words, as compared to cotton, viscose fibers showed higher degrees of carboxymethylation but lower accessibility of the carboxyl groups to dye molecules. The divergence between the fiber types is attributed to differences in the spatial distribution of substituted carboxymethyl groups within their structures, as well as the inherently greater swelling propensity of the viscose as compared to cotton. Further work is under way to determine if the order of performance as measured through dye sorption (cotton better than viscose) will also hold true if the performance metric is changed to water and moisture sorption. [ABSTRACT FROM AUTHOR]

Published
2024
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3. Measuring the concentration of carboxylic acid groups in torrefied spruce wood

Author

Khazraie Shoulaifar, Tooran, DeMartini, Nikolai, Ivaska, Ari, Fardim, Pedro, and Hupa, Mikko

Subjects
*CARBOXYLIC acids, *SPRUCE, *THERMAL analysis, *ENERGY density, *BIOMASS energy, *ENERGY storage, *POTENTIOMETRY, *CHEMICAL decomposition
Abstract

Abstract: Torrefaction is moderate thermal treatment (∼200–300°C) to improve the energy density, handling and storage properties of biomass fuels. In biomass, carboxylic sites are partially responsible for its hygroscopic. These sites are degraded to varying extents during torrefaction. In this paper, we apply methylene blue sorption and potentiometric titration to measure the concentration of carboxylic acid groups in spruce wood torrefied for 30min at temperatures between 180 and 300°C. The results from both methods were applicable and the values agreed well. A decrease in the equilibrium moisture content at different humidity was also measured for the torrefied wood samples, which is in good agreement with the decrease in carboxylic acid sites. Thus both methods offer a means of directly measuring the decomposition of carboxylic groups in biomass during torrefaction as a valuable parameter in evaluating the extent of torrefaction which provides new information to the chemical changes occurring during torrefaction. [Copyright &y& Elsevier]

Published
2012
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4. Towards molecular weight-dependent uses of kraft lignin

Author

Tagami, Ayumu and Tagami, Ayumu

Abstract

There is growing demand for a more efficient use of polymers that originate from renewable feedstocks due to the depleting supply of fossil fuels, based on economic and environmental reasons. As a result, lignin has attracted renewed interest as a resource for various bioproducts. Lignin is a natural biopolymer with a high carbon content and is composed of aromatic moieties, with a high level of polar functionalities. This makes it a unique precursor for certain high-value applications, such as in biofuels, bioplastics, composite materials, carbon fibers and activated carbons and as a source of phenolic monomers and fine chemicals. Industrial lignins are formed as byproducts of pulping processes (such as kraft, sulfite or alkaline pulping) or result from the biorefining process, where carbohydrates are used for sugar production. Lignin’s intrinsic structure is significantly modified during the processing of lignocellulose, resulting in the formation of more diverse, condensed and less reactive raw materials. Since molecular mass and polydispersity are the most important parameters affecting the chemical reactivity and thermal properties of lignin, additional process steps to improve the quality of crude technical lignins, including kraft lignin, are needed. Solvent extraction is a potentially useful technique for further improving the polydispersity of technical lignins. This work summarizes the impact of solvent fractionation on the chemical structure, antioxidant activity, heating value, and thermal and sorption properties of industrial hardwood and softwood kraft lignins. The purpose was to understand the correlation between certain structural features in the lignin fractions and their properties to select the appropriate solvent combinations for specific applications of lignin raw materials. Four common industrial solvents, namely, ethyl acetate, ethanol, methanol and acetone, in various combinations were used to separate both spruce and eucalyptus kraft lignins

Published
2018

5. Evaluation of Red Marine AlgaKappaphycus alvareziias Biosorbent for Methylene Blue: Isotherm, Kinetic, and Mechanism Studies

Author

T. Bhagavathi Pushpa, J. Jegan, J. Vijayaraghavan, Kuppusamy Vijayaraghavan, and S.J. Sardhar Basha

Subjects
Aromatic compounds, Langmuir, General Chemical Engineering, Filtration and Separation, Wastewater, Isotherms, Biosorption isotherms, symbols.namesake, chemistry.chemical_compound, Kappaphycus alvarezii, Biosorption mechanism, Methylene blue sorption, Freundlich equation, Chromatography, Aqueous solution, biology, Process Chemistry and Technology, Enzyme kinetics, Operational parameters, Biosorption, Fourier transform infrared spectroscopy, Langmuir adsorption model, Sorption, General Chemistry, Seaweed, biology.organism_classification, Methylene Blue, Kinetics, pH effects, Correlation coefficient, chemistry, Initial dye concentration, symbols, Equilibrium solutions, Scanning electron microscopy, Methylene blue, Nuclear chemistry
Abstract

In this work, non-living red seaweed (Kappaphycus alvarezii) biomass was investigated as a new biosorbent of methylene blue from aqueous solution. The effect of operational parameters such as equilibrium pH, agitation time, initial dye concentrations, and biosorbent dosage on the biosorption capacity of Kappaphycus alvarezii was studied. The equilibrium solution pH was found to profoundly affect methylene blue sorption capacity of Kappaphycus alvarezii with pH 8 found to be optimum. Evidence from Fourier-transform infrared spectroscopy and scanning electron microscopy pictures confirmed the dye biosorption mechanism as electrostatic interaction between the negatively charged seaweed surface and positively charged methylene blue. Biosorption isotherms indicated that Kappaphycus alvarezii exhibited methylene blue uptake of 74.4 mg/g, according to the Langmuir model. The equilibrium isotherm data were evaluated using the Freundlich, Langmuir, Redlich-Peterson, and Toth models. Kinetic studies revealed that methylene blue uptake was fast with 97% or more of the uptake occurred within 60 min of contact time. The pseudo first and second order models were applied to describe kinetic data, of which the pseudo-first order described experimental data better with high correlation coefficient and low percentage of error values. � , Copyright � Taylor & Francis Group, LLC.

Published
2014
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7. Thermodynamics and kinetic studies of biosorption of a basic dye from aqueous solution using green algae Ulothrix sp

Author

Çetin Doğar, Ahmet Gürses, Esra Özkan, Metin Açıkyıldız, and Bayburt University

Subjects
Ulothrix, Basic dyes, chemistry.chemical_compound, Isosteric enthalpy, Colloid and Surface Chemistry, Biosorption mechanism, Chlorophyta, Dye removal, green alga, Kinetic theory, Coloring Agents, Mixing rates, Algae, Green, reaction time, Aqueous solution, Molecular Structure, biology, Sorption kinetics, Contact time, article, Surfaces and Interfaces, General Medicine, Solutions, pH effects, priority journal, Thermodynamics, Pseudo-second-order kinetic models, Entropy value, temperature measurement, Methylene blue, biosorption, Biotechnology, Sorbent, Solution equilibrium, Algae, Sorbent particles, Enthalpy, Inorganic chemistry, Kinetics, concentration process, Absorption, Water Purification, Adsorption equilibria, Adsorption, Ulothrix sp, Methylene blue sorption, enthalpy, controlled study, Physical interactions, Physical and Theoretical Chemistry, Aqueous solutions, nonhuman, pH measurement, Biosorption, Water, biology.organism_classification, chemistry, Thermodynamics and kinetics, Initial dye concentration, molecular interaction, Sorbates, Biosorbents, aqueous solution, entropy, biomass conversion, Water Pollutants, Chemical, adsorption kinetics
Abstract

This study addresses removal of a basic dye, methylene blue, from aqueous Solutions by using dried Ulothrix sp. biomass as biosorbent. The effects of the initial dye concentration, contact time. temperature, solution equilibrium pH, biosorbent dosage, and mixing rate on biosorption of the dye have been investigated. It was found that 30 min is sufficient in order to reach adsorption equilibrium. The amount of methylene blue adsorbed onto Ulothrix sp. increased with increasing equilibrium pH and mixing rate, in contrary, it decreased with increasing temperature and sorbent dosage. The process followed the pseudo-second-order kinetic model. The isosteric enthalpy and entropy values were calculated as -11.8 kJ/mol and 37.5 J/(mol K). respectively. In addition, the results suggest that the physical interactions between sorbent particles and sorbate ions play an important role for the adsorption of methylene blue onto the biosorbent. (C) 2009 Elsevier B.V. All rights reserved.

Published
2010
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8. Solvent fractionation of softwood and hardwood kraft lignins for more efficient uses: compositional, structural, thermal, antioxidant and sorption properties

Author

Tagami, Ayumu, Gioia, Claudio, Lauberts, Maris, Budnyak, Tetyana, Moriana, Rosana, Lindström, Mikael, Sevastyanova, Olena, Tagami, Ayumu, Gioia, Claudio, Lauberts, Maris, Budnyak, Tetyana, Moriana, Rosana, Lindström, Mikael, and Sevastyanova, Olena

Abstract

This work summarizes the impact of solvent fractionation on the chemical structure, antioxidant activity, heating values, and thermal and sorption properties of industrial hardwood and softwood kraft lignins. The aim was to develop a simple approach for the obtaining of lignin fractions with a tailored properties for the certain material applications. Four common industrial solvents, namely, ethyl acetate, ethanol, methanol and acetone, in various combinations efficiently separated both spruce and eucalyptus kraft lignins into fractions with low polydispersities. The ethanol fraction of spruce and the ethyl acetate fraction of eucalyptus afforded the highest yields. Gel-permeation chromatography analysis was used to evaluate the efficiency of the chosen solvent combination for lignin fractionation. The composition and structure of the lignin material was characterized by elemental analysis, analytical pyrolysis (Py-GC/MS/FID) and 31P NMR spectroscopy. The thermal properties of the lignin samples were studied by thermogravimetric analysis. Proximate analysis data (ash, volatile components, organic matter and fixed carbon) were obtained through the direct measurement of weight changes in each experimental curve, and the high heating values (in MJ/kg) were calculated according to equations suggested in the literature. The sorption properties of fractionated kraft lignins were studied with respect to methylene blue dye. The clear correlation between certain structural features in the lignin fractions and the properties of the lignin provides useful information for selecting the appropriate solvent combinations for specific applications of lignin raw materials, including as antioxidants, biofuels or sorbents in water treatment processes., QC 20180821

9. Solvent fractionation of softwood and hardwood kraft lignins for more efficient uses: compositional, structural, thermal, antioxidant and sorption properties

Author

Tagami, Ayumu, Gioia, Claudio, Lauberts, Maris, Budnyak, Tetyana, Moriana, Rosana, Lindström, Mikael, Sevastyanova, Olena, Tagami, Ayumu, Gioia, Claudio, Lauberts, Maris, Budnyak, Tetyana, Moriana, Rosana, Lindström, Mikael, and Sevastyanova, Olena

Abstract

This work summarizes the impact of solvent fractionation on the chemical structure, antioxidant activity, heating values, and thermal and sorption properties of industrial hardwood and softwood kraft lignins. The aim was to develop a simple approach for the obtaining of lignin fractions with a tailored properties for the certain material applications. Four common industrial solvents, namely, ethyl acetate, ethanol, methanol and acetone, in various combinations efficiently separated both spruce and eucalyptus kraft lignins into fractions with low polydispersities. The ethanol fraction of spruce and the ethyl acetate fraction of eucalyptus afforded the highest yields. Gel-permeation chromatography analysis was used to evaluate the efficiency of the chosen solvent combination for lignin fractionation. The composition and structure of the lignin material was characterized by elemental analysis, analytical pyrolysis (Py-GC/MS/FID) and 31P NMR spectroscopy. The thermal properties of the lignin samples were studied by thermogravimetric analysis. Proximate analysis data (ash, volatile components, organic matter and fixed carbon) were obtained through the direct measurement of weight changes in each experimental curve, and the high heating values (in MJ/kg) were calculated according to equations suggested in the literature. The sorption properties of fractionated kraft lignins were studied with respect to methylene blue dye. The clear correlation between certain structural features in the lignin fractions and the properties of the lignin provides useful information for selecting the appropriate solvent combinations for specific applications of lignin raw materials, including as antioxidants, biofuels or sorbents in water treatment processes., QC 20180821

10. Solvent fractionation of softwood and hardwood kraft lignins for more efficient uses: compositional, structural, thermal, antioxidant and sorption properties

Author

Tagami, Ayumu, Gioia, Claudio, Lauberts, Maris, Budnyak, Tetyana, Moriana, Rosana, Lindström, Mikael, Sevastyanova, Olena, Tagami, Ayumu, Gioia, Claudio, Lauberts, Maris, Budnyak, Tetyana, Moriana, Rosana, Lindström, Mikael, and Sevastyanova, Olena

Abstract

This work summarizes the impact of solvent fractionation on the chemical structure, antioxidant activity, heating values, and thermal and sorption properties of industrial hardwood and softwood kraft lignins. The aim was to develop a simple approach for the obtaining of lignin fractions with a tailored properties for the certain material applications. Four common industrial solvents, namely, ethyl acetate, ethanol, methanol and acetone, in various combinations efficiently separated both spruce and eucalyptus kraft lignins into fractions with low polydispersities. The ethanol fraction of spruce and the ethyl acetate fraction of eucalyptus afforded the highest yields. Gel-permeation chromatography analysis was used to evaluate the efficiency of the chosen solvent combination for lignin fractionation. The composition and structure of the lignin material was characterized by elemental analysis, analytical pyrolysis (Py-GC/MS/FID) and 31P NMR spectroscopy. The thermal properties of the lignin samples were studied by thermogravimetric analysis. Proximate analysis data (ash, volatile components, organic matter and fixed carbon) were obtained through the direct measurement of weight changes in each experimental curve, and the high heating values (in MJ/kg) were calculated according to equations suggested in the literature. The sorption properties of fractionated kraft lignins were studied with respect to methylene blue dye. The clear correlation between certain structural features in the lignin fractions and the properties of the lignin provides useful information for selecting the appropriate solvent combinations for specific applications of lignin raw materials, including as antioxidants, biofuels or sorbents in water treatment processes., QC 20180821

11. Solvent fractionation of softwood and hardwood kraft lignins for more efficient uses: compositional, structural, thermal, antioxidant and sorption properties

Author

Tagami, Ayumu, Gioia, Claudio, Lauberts, Maris, Budnyak, Tetyana, Moriana, Rosana, Lindström, Mikael, Sevastyanova, Olena, Tagami, Ayumu, Gioia, Claudio, Lauberts, Maris, Budnyak, Tetyana, Moriana, Rosana, Lindström, Mikael, and Sevastyanova, Olena

Abstract

This work summarizes the impact of solvent fractionation on the chemical structure, antioxidant activity, heating values, and thermal and sorption properties of industrial hardwood and softwood kraft lignins. The aim was to develop a simple approach for the obtaining of lignin fractions with a tailored properties for the certain material applications. Four common industrial solvents, namely, ethyl acetate, ethanol, methanol and acetone, in various combinations efficiently separated both spruce and eucalyptus kraft lignins into fractions with low polydispersities. The ethanol fraction of spruce and the ethyl acetate fraction of eucalyptus afforded the highest yields. Gel-permeation chromatography analysis was used to evaluate the efficiency of the chosen solvent combination for lignin fractionation. The composition and structure of the lignin material was characterized by elemental analysis, analytical pyrolysis (Py-GC/MS/FID) and 31P NMR spectroscopy. The thermal properties of the lignin samples were studied by thermogravimetric analysis. Proximate analysis data (ash, volatile components, organic matter and fixed carbon) were obtained through the direct measurement of weight changes in each experimental curve, and the high heating values (in MJ/kg) were calculated according to equations suggested in the literature. The sorption properties of fractionated kraft lignins were studied with respect to methylene blue dye. The clear correlation between certain structural features in the lignin fractions and the properties of the lignin provides useful information for selecting the appropriate solvent combinations for specific applications of lignin raw materials, including as antioxidants, biofuels or sorbents in water treatment processes., QC 20180821

12. Solvent fractionation of softwood and hardwood kraft lignins for more efficient uses: compositional, structural, thermal, antioxidant and sorption properties

Author

Tagami, Ayumu, Gioia, Claudio, Lauberts, Maris, Budnyak, Tetyana, Moriana, Rosana, Lindström, Mikael, Sevastyanova, Olena, Tagami, Ayumu, Gioia, Claudio, Lauberts, Maris, Budnyak, Tetyana, Moriana, Rosana, Lindström, Mikael, and Sevastyanova, Olena

Abstract

This work summarizes the impact of solvent fractionation on the chemical structure, antioxidant activity, heating values, and thermal and sorption properties of industrial hardwood and softwood kraft lignins. The aim was to develop a simple approach for the obtaining of lignin fractions with a tailored properties for the certain material applications. Four common industrial solvents, namely, ethyl acetate, ethanol, methanol and acetone, in various combinations efficiently separated both spruce and eucalyptus kraft lignins into fractions with low polydispersities. The ethanol fraction of spruce and the ethyl acetate fraction of eucalyptus afforded the highest yields. Gel-permeation chromatography analysis was used to evaluate the efficiency of the chosen solvent combination for lignin fractionation. The composition and structure of the lignin material was characterized by elemental analysis, analytical pyrolysis (Py-GC/MS/FID) and 31P NMR spectroscopy. The thermal properties of the lignin samples were studied by thermogravimetric analysis. Proximate analysis data (ash, volatile components, organic matter and fixed carbon) were obtained through the direct measurement of weight changes in each experimental curve, and the high heating values (in MJ/kg) were calculated according to equations suggested in the literature. The sorption properties of fractionated kraft lignins were studied with respect to methylene blue dye. The clear correlation between certain structural features in the lignin fractions and the properties of the lignin provides useful information for selecting the appropriate solvent combinations for specific applications of lignin raw materials, including as antioxidants, biofuels or sorbents in water treatment processes., QC 20180821

13. Solvent fractionation of softwood and hardwood kraft lignins for more efficient uses: compositional, structural, thermal, antioxidant and sorption properties

Author

Tagami, Ayumu, Gioia, Claudio, Lauberts, Maris, Budnyak, Tetyana, Moriana, Rosana, Lindström, Mikael, and Sevastyanova, Olena

Subjects
Heat capacity, Antioxidant activity, Methylene blue sorption, Trävetenskap, Spruce kraft lignin, Structural analysis, Thermal stability, Wood Science, Eucalyptus kraft lignin, Solvent fractionation
Abstract

This work summarizes the impact of solvent fractionation on the chemical structure, antioxidant activity, heating values, and thermal and sorption properties of industrial hardwood and softwood kraft lignins. The aim was to develop a simple approach for the obtaining of lignin fractions with a tailored properties for the certain material applications. Four common industrial solvents, namely, ethyl acetate, ethanol, methanol and acetone, in various combinations efficiently separated both spruce and eucalyptus kraft lignins into fractions with low polydispersities. The ethanol fraction of spruce and the ethyl acetate fraction of eucalyptus afforded the highest yields. Gel-permeation chromatography analysis was used to evaluate the efficiency of the chosen solvent combination for lignin fractionation. The composition and structure of the lignin material was characterized by elemental analysis, analytical pyrolysis (Py-GC/MS/FID) and 31P NMR spectroscopy. The thermal properties of the lignin samples were studied by thermogravimetric analysis. Proximate analysis data (ash, volatile components, organic matter and fixed carbon) were obtained through the direct measurement of weight changes in each experimental curve, and the high heating values (in MJ/kg) were calculated according to equations suggested in the literature. The sorption properties of fractionated kraft lignins were studied with respect to methylene blue dye. The clear correlation between certain structural features in the lignin fractions and the properties of the lignin provides useful information for selecting the appropriate solvent combinations for specific applications of lignin raw materials, including as antioxidants, biofuels or sorbents in water treatment processes. QC 20180821

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