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1
Granström, Andreas. "Adsorption of methylene blue on iron-doped lignin hydrochar." Thesis, Umeå universitet, Kemiska institutionen, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-150540.
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Welagedara, Asanka. "Phosphorus Removal and Methylene Blue Adsorption by Porous Calcium Silicate Hydrate." Thesis, KTH, Mark- och vattenteknik (flyttat 20130630), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-171836.
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Nutrients (nitrogen and phosphorus) should be removed and recycled from wastewater in order to reduce the nutrient load to recipient waters, avoiding contamination of groundwater and conserve resources. There is a need to pay more attention to phosphorus (P) removal and recycling from wastewater due to limited availability of phosphorus recourses. For such purpose reactive filter media can be used to remove nutrient from wastewater as a sustainable technology. The present study was aimed to evaluate calcium silicate hydrate crystallization in Absol as a reactive filter media for removal and recycle of phosphorus from household wastewater and assess physical and chemical characteristics of Absol. A study of the color removing capacity of Absol was also performed. Several batch experiments were done for comparing absorption mechanism. Collected data were applied to Langmuir and Freundlich isotherm models to study type of adsorption isotherms and pseudofirst- order and second order models were run for study of adsorption kinetics. The experiment demonstrated a very high P and Methylene Blue (MB) sorption capacity. The amount of adsorbed P and MB vary with initial solution concentrations, contact time, and adsorbent dosage. Both equilibrium data (P, MB) were fitted very well in the Langmuir isotherm equation, confirming the monolayer physical sorption and adsorption kinetic followed by the pseudo-second order kinetic model. It is concluded that Absol can have potential to be use for the removal of P, textile dye contaminants and probably also pharmaceuticals present in wastewater.
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Chen, Qihang. "Exploiting High Surface Area Polymer Gels for Dye Adsorption." University of Akron / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=akron1619184015747879.
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Filho, Rivadavia Tavares Martins. "Biosorbents - water hyacinth biomass and spheres alginate / cashew gum - for adsorption of methylene blue." Universidade Federal do CearÃ, 2012. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=8326.
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nÃo hÃIn this work was carried out an extensive investigation of the adsorption properties of synthetic dyes on different parts (rhizome, root, stolon and petiole) of Eichhornia crassipes (water hyacinth) and a comparison with the adsorption capacity of the biopolymer alginate beads doped with water hyacinth biomass. The biomasses and spheres were structurally characterized by infrared spectroscopy, scanning electron microscopy - SEM and thermal analysis (thermogravimetric analysis - TGA and Differential Scanning Calorimetry - DSC). The kinetics of adsorption processes were monitored by UV and visible spectroscopy - UV / VIS and the data applied to the models of Freundlich and Languimir. Synthetic anionic dyes (methyl orange), cationic (methylene blue) and azo (indigo carmine) were used in the investigation. Adsorption studies was obtained, under controlled agitation of 70 rpm and temperature ranging between 25ÂC and 45ÂC at concentrations of dye in the range 10-250 mg/L and pH 2-12. The best results were achieved with a dye initial concentration of 100 mg/g, an initial quantity of 60 mg biosorbent, at temperature of 45 ÂC and at basic pH. Among the tested dyes, methylene blue exhibited the best adsorption capacity. The study of adsorption kinetics showed a better fit to the model of pseudo-second order and intraparticle diffusion is involved in the mechanism of adsorption. In the study of the isotherms, the result shows best fit to data by the Langmuir and Freundlich equations, with a maximum capacity of adsorption of methylene blue dye from 819.7 mg/g at 25 ÂC, to the root. A temperature increase caused an increase in system adsorption capacity and also led to an increase in time to the system reach equilibrium. The values of the rate constant for pseudo-second order increased with increasing temperature. An increase in initial dye concentration caused an increase in the amount of dye adsorbed. The activation energy for all biosorbents are in the range 20-40 kJ.mol-1 demonstrated that the adsorption processes are physical. The thermodynamic parameters ∆HÂ, ∆SÂ and ΔGÂ, for most biosorbents indicate that the process is exothermic in nature, spontaneous and favorable, except for the sphere of ALG/GC/Biomass where values obtained showed endothermic nature. The desorption study showed that the biosorbents can be reused.
Neste trabalho foi realizada uma investigaÃÃo extensiva das propriedades de adsorÃÃo do corante azul de metileno em diferentes partes (rizoma, raiz, estolÃo e pecÃolo) de Eichhornia Crassipes (aguapÃ), bem como uma comparaÃÃo com a adsorÃÃo em esferas do biopolÃmero alginato dopadas com biomassa de aguapÃ. As biomassas e esferas foram caracterizadas estruturalmente atravÃs de tÃcnicas de espectroscopia de infravermelho, microscopia eletrÃnica de varredura â MEV e anÃlises tÃrmicas (anÃlise termogravimÃtrica â TGA e Calorimetria Diferencial de Varredura â DSC). As cinÃticas dos processos de adsorÃÃo foram monitoradas por espectroscopia de ultravioleta e visÃvel â UV/VIS e os dados obtidos aplicados nos modelos de Languimir, Freundlich, Temkin e BET. Foram utilizados corantes sintÃticos aniÃnico (alaranjado de metila), catiÃnico (azul de metileno) e azo (Ãndigo carmin). Os estudos de adsorÃÃo foram obtidos, sob agitaÃÃo controlada de 70 rpm e temperatura variando entre 25ÂC e 45ÂC, e concentraÃÃes de corante na faixa de 10 a 250 mg/L, em pH de 2 a 12. Os melhores resultados foram alcanÃados utilizando uma concentraÃÃo inicial de corante de 100 mg/g, uma massa inicial de biosorvente de 60 mg a temperatura de 45 ÂC e em pH bÃsico. Dentre os corantes testados o azul de metileno foi o que apresentou melhores resultados de adsorÃÃo. O estudo da cinÃtica de adsorÃÃo apresentou um melhor ajuste ao modelo de pseudo-segunda ordem e a difusÃo intrapartÃcula està envolvida no mecanismo de adsorÃÃo. No estudo das isotermas de equilÃbrio, o resultado mostra melhor ajuste das equaÃÃes de Langmuir e Freundlich pelos dados, com capacidade mÃxima de adsorÃÃo do corante azul de metileno de 819,7 mg/g a 25 ÂC, para a raiz do aguapÃ. A elevaÃÃo na temperatura do sistema provocou aumento na capacidade mÃxima adsorvida e tambÃm provocou um aumento no tempo para o sistema atingir o equilÃbrio. Os valores da constante de velocidade de pseudo-segunda ordem aumentaram com o aumento da temperatura. Um aumento na concentraÃÃo inicial do corante provocou um aumento na quantidade de corante adsorvida. A energia de ativaÃÃo para todos os biosorventes, da ordem de 20 â 40 kJ.mol-1, demonstrou que o processo à de natureza fÃsica. Os parÃmetros termodinÃmicos ∆HÂ, ∆S e ∆GÂ, para a maioria dos biosorventes indicam que o processo à de natureza exotÃrmica, espontÃnea e favorÃvel, com exceÃÃo da esfera de ALG/GC/Biomassa que mostrou valores de natureza endotÃrmica. O estudo de dessorÃÃo demonstrou que os biosorventes podem ser reutilizados.
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BRUNO, MARIZA. "Utilização de zeólitas sintetizadas a partir de cinzas de carvão na remoção de corante em água." reponame:Repositório Institucional do IPEN, 2008. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11509.
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Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP
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Li, Yan. "The Current Response of a Mediated Biological Fuel Cell with Acinetobacter calcoaceticus: The Role of Mediator Adsorption and Reduction Kinetics." Thesis, University of Canterbury. Chemical and Process Engineering, 2013. http://hdl.handle.net/10092/8017.
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Microbial fuel cells (MFC) are an emerging renewable technology which converts complex organic matter to electrical power using microorganisms as the biocatalyst. A variety of biological relevant organic matters such as glucose, acetate and ethanol have been utilized for the successful operation of a MFC. In this regard, the investigation of a MFC inoculated with ethanol oxidizing bacteria is of particular interest for this research due to its ability to simultaneously produce electricity while reducing ethanol pollution (a type of volatile organic carbon (VOC) pollutant) with potential use in modified biological air pollution control technology such as biofiltration.
In this research, ethanol-oxidizing microbial species isolated from soil and compost samples were identified, with Acinetobacter calcoaceticus being the dominant strain. In order to understand the metabolism of the anode microbial cells, which is considered to be the key dictating the performance of a MFC, a systematic analysis/optimization of the growth rate and biomass production for A. calcoaceticus were carried out. A maximum specific growth rate with a final biomass concentration of 1.68 g/l was derived when aerated at a rate of 0.68 vvm.
It has been recognized that one of the principle constraints in increasing the current density of MFCs is the electron transfer from the bacteria to the anode. In this sense, the addition of a redox mediator, which facilitates the process of the electron transfer, is desired for the efficient operation of a MFC. Thionine, methylene blue (MB), resorufin and potassium ferricyanide that have been profusely utilized as effective mediator compounds in many MFC studies, however, specific information on the biomass sorption of these compounds was lacking and therefore were selected for this research. All mediators tested were reduced biologically in A. calcoaceticus inoculated samples as indicated by the color transition from the pigmented oxidized form to the colorless reduced form. Subsequent tests on mediator color removal revealed that physical adsorption by the biomass, aggregation as well as precipitation accounted for a significant portion of the color loss for thionine and MB. It was speculated that the fraction of the initial mediator concentration sequestered, aggregated and/or precipitated no longer contributed to the electron transfer process, resulting in a current production which was proportional to the measurable mediator concentration remained in anode solution. To verify this hypothesis, chronoamperometric measurements were conducted for various mediator systems at known initial and measurable concentrations. The data obtained on the current produced were in good agreement with the theoretical predictions calculated from the actual mediator concentration, suggesting that the current produced depended on the concentration of mediator remaining in solution.
Finally, the microbial reduction kinetics and the cytotoxicity of potassium ferricyanide were analyzed. The reduction of potassium ferricyanide followed zero order kinetics with the specific reduction rate increased as the initial mediator concentration increased from 1 mM to 200 mM. Inhibitory effects on cell growth were observed at initial potassium ferricyanide concentration of 50 mM.
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Contreras, Osmary C. "A comparative study of tailored activated carbon from waste tires against commercial activated carbon (F400) for the removal of Methylene Blue." University of Cincinnati / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1383812437.
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Santos, EvÃnia Carvalho dos. "Synthesis and characterization of Al-MCM-41using kaolin as raw material by hydrothermal route and assessment of its performance in methylene blue adsorption." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=15944.
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The mesoporous materials Al-MCM-41 produced from kaolin, low cost raw material, by means of hydrothermal acid treatment route, has shown potential for being used as adsorbent in removal process of methylene blue. The process of synthesis of Al-MCM-41 is based on calcination of kaolin, dealumination by acid treatment, hydrothermal synthesis and extraction of the surfactant. The characterization of de obtained mesoporous material was carried out by techniques such as: X-ray diffraction, vibrational spectroscopy in the infrared, 29Si and 27Al nuclear magnetic resonance in the solid state, scanning electron microscopy, transmission electron microscopy and N2 adsorption/desorption. The X-ray diffraction at low angles allowed the determination of the cell parameter, which was 4.02 nm. The analyses of scanning and transmission electron microscopy revealed important morphological properties of the synthesized material. N2 adsorption/desorption showed a BET specific surface area of 1,303 m2 g-1, pore volume of 1.23 cm3 g-1 and average diameter of 2.45 nm. PZC measurements showed a pHPZC of 2.69. The adsorption of methylene blue by Al-MCM-41 adsorbent showed high kinetic and high adsorption capacity, with values around 316 mg g-1.O material mesoporoso Al-MCM-41 produzido a partir de caulim, matÃria-prima de baixo custo, por meio de rota hidrotÃrmica com tratamento Ãcido, mostrou-se promissor para ser usado como adsorvente do corante azul de metileno. O processo de sÃntese da Al-MCM-41 Ã baseado na calcinaÃÃo do caulim, desaluminizaÃÃo por tratamento Ãcido, sÃntese hidrotÃrmica e eliminaÃÃo do surfactante. A caracterizaÃÃo do material mesoporoso foi realizada por meio de tÃcnicas como: difraÃÃo de raios-X, espectroscopia vibracional na regiÃo do infravermelho, ressonÃncia magnÃtica nuclear no estado sÃlido de 29Si e 27Al, microscopia eletrÃnica de varredura, microscopia eletrÃnica de transmissÃo e adsorÃÃo de N2. A anÃlise de difraÃÃo de raios-X em baixo Ãngulo da Al-MCM-41 permitiu a determinaÃÃo do parÃmetro de cÃlula que apresentou valor de 4,02 nm. As anÃlises de microscopia eletrÃnica de varredura e de transmissÃo revelaram importantes propriedades morfolÃgicas do material sintetizado. Utilizando as medidas de adsorÃÃo e desorÃÃo de gÃs N2 a Ãrea superficial especÃfica BET da Al-MCM-41 apresentou valor 1.303 m2 g-1, com um volume de poros de 1,23 cm3 g-1 e diÃmetro mÃdio de 2,45 nm. O teste do PZC determinou um pHPZC de 2,69. Os testes de adsorÃÃo do azul de metileno pelo adsorvente Al-MCM-41 mostraram que o mesmo apresenta alta capacidade de adsorÃÃo com valores em torno de 316 mg g-1.
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Bonetto, Luis Rafael. "Estudo da adsorção do corante azul de metileno por um resíduo sólido da indústria do suco de maça." reponame:Repositório Institucional da UCS, 2016. https://repositorio.ucs.br/handle/11338/1232.
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O desenvolvimento de novas tecnologias para o tratamento de efluentes contendo corantes tem sido alvo de grande interesse nos últimos anos, devido ao aumento da conscientização acerca da preservação ambiental, além da rigidez da legislação específica. Neste contexto, a adsorção tem se mostrado uma técnica bastante promissora para a remoção de cor, uma vez que apresenta custo relativamente baixo, além de possuir apreciável eficiência. Considerando os aspectos mencionados, este trabalho teve por objetivo avaliar a capacidade adsorvente de um resíduo sólido proveniente da indústria de suco de maçã na remoção do corante catiônico azul de metileno em meio aquoso. Após sua coleta e preparação, o bagaço de maçã foi caracterizado por meio de várias técnicas, como análise elementar, espectroscopia no infravermelho com Transformada de Fourier, espectroscopia de ressonância magnética nuclear de carbono-13 no estado sólido, análise termogravimétrica e microscopia eletrônica de varredura. A área superficial específica, bem como o diâmetro médio das partículas e o pH no ponto de carga zero foram igualmente determinados. Após a caracterização, a capacidade de adsorção do bagaço de maçã foi investigada em sistema de batelada. A concentração de corante remanescente em todos os experimentos de adsorção foi estimada por meio de uma curva de calibração, utilizando-se a técnica de espectroscopia de absorção molecular na região do visível. Além disso, a influência de parâmetros experimentais, tais como concentração inicial do corante, massa de adsorvente, pH do meio, velocidade de agitação do sistema e temperatura, foi avaliada por meio da execução de planejamento fatorial. Com relação ao equilíbrio de adsorção, foi verificado que a isoterma de Langmuir foi a que melhor se ajustou aos resultados experimentais em todas as temperaturas avaliadas, apresentando valores para a constante de Langmuir (KL) e para a capacidade máxima de adsorção (qm) nas faixas 0,0951 a 0,1122 L mg-1 e 97,60 a 133,15 mg g-1, respectivamente. Do ponto de vista termodinâmico, os resultados revelaram um processo físico e espontâneo, com valores de ΔG°ads menores do que -0,59 kJ mol-1, enquanto que ΔH°ads e ΔS°ads resultaram em -19,84 kJ mol-1 e -62,72 J mol-1 K-1, respectivamente. No que se refere à cinética de adsorção, o modelo de pseudossegunda ordem foi o que melhor descreveu o processo. O estudo dos mecanismos de transferência de massa demonstrou que o processo de adsorção é controlado tanto pela difusão no filme estagnado que recobre as partículas, quanto pela difusão intrapartícula no interior dos poros das mesmas para a maior parte das condições de processo verificadas. Os valores para o coeficiente de transferência de massa através do filme estagnado (kf) situaram-se na faixa de 0,57 × 10-6 a 3,13 × 10-5 m min-1, enquanto que a constante de velocidade de difusão intrapartícula (kint) ficou compreendida entre 4,43 e 9,81 mg g-1 min-1. Por fim, o bagaço de maçã mostrou ser um bom adsorvente para a remoção do corante catiônico azul de metileno, podendo ser reutilizado em mais de um ciclo de remoção, sem perdas significativas de propriedades após o processo de regeneração utilizando etanol como solvente.Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2016-07-22T19:21:35Z No. of bitstreams: 1 Dissertacao Luis Rafael Bonetto.pdf: 3625274 bytes, checksum: b586378c3ea99b12edd36246954da943 (MD5)
Made available in DSpace on 2016-07-22T19:21:36Z (GMT). No. of bitstreams: 1 Dissertacao Luis Rafael Bonetto.pdf: 3625274 bytes, checksum: b586378c3ea99b12edd36246954da943 (MD5) Previous issue date: 2016-07-22
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES.
The development of new technologies for the treatment of wastewater containing dyes has generated a great interest in recent years, due to increase awareness about environmental preservation, in addition to the rigidity of specific legislation. In this sense, the adsorption has been a promising technique for color removal, once it offers relatively low-cost, besides to be endowed appreciable efficiency. Considering the mentioned aspects, this study aimed to evaluate the adsorption capacity of a solid agro-industrial waste from apple juice industry (pomace) in the removal of methylene blue cationic dye in aqueous medium. After its collection and preparation, the biomass was characterized by means of several techniques, including elemental analysis, Fourier transform infrared spectroscopy, solid-state 13C nuclear magnetic resonance spectroscopy, thermogravimetric analysis and scanning electron microscopy. The specific surface area, as well as the average diameter of the particles and the pH at the point of zero charge were also determined. After characterization, the adsorption capacity of the apple pomace was investigated in a batch system. The concentration of dye in all remaining adsorption experiments was estimated using a calibration curve by means of molecular absorption spectroscopy in the visible region. Furthermore, the influence of experimental parameters such as initial dye concentration, adsorbent amount, pH of the medium, stirring rate of the system and temperature were also evaluated by a factorial design. Concerning the adsorption equilibrium, the Langmuir isotherm provided the best fit for the experimental data for all temperature evaluated, with values for the Langmuir constant (KL) and maximum adsorption capacity (qm) situated in the ranges from 0.0951 to 0.1122 L mg-¹ and 97.60 to 133.15 mg g-¹, respectively. From the thermodynamic point of view, the results revealed a physical and spontaneous adsorption process, with values lower than -0.59 kJ mol-1 for ΔG°ads, while ΔH°ads and ΔS°ads resulted in -19.84 kJ mol-1 and -62.72 J mol-1 K-1, respectively. The adsorption kinetics was better described using a pseudo-second-order model. Studies on the mechanisms of mass transfer have shown that the adsorption process is controlled by either diffusion on the stagnant film that covering the particles and intraparticle diffusion inside particle porous in the most part of experimental conditions tested. The values of stagnant film mass transfer coefficient (kf) lie within 0.57 × 10-6 to 3.13 × 10-5 m min-1 range, while intraparticle diffusion rate constant (kint) remained between 4.43 and 9.81 mg g-1 min-1. Finally, the apple pomace shown to be a suitable adsorbent for the removal of methylene blue cationic dye and can be reused for several adsorption cycles without significant properties losses after the regeneration process using ethanol as a solvent.
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Bonetto, Luís Rafael. "Estudo da adsorção do corante azul de metileno por um resíduo sólido da indústria do suco de maça." reponame:Repositório Institucional da UCS, 2016. https://repositorio.ucs.br/handle/11338/1232.
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O desenvolvimento de novas tecnologias para o tratamento de efluentes contendo corantes tem sido alvo de grande interesse nos últimos anos, devido ao aumento da conscientização acerca da preservação ambiental, além da rigidez da legislação específica. Neste contexto, a adsorção tem se mostrado uma técnica bastante promissora para a remoção de cor, uma vez que apresenta custo relativamente baixo, além de possuir apreciável eficiência. Considerando os aspectos mencionados, este trabalho teve por objetivo avaliar a capacidade adsorvente de um resíduo sólido proveniente da indústria de suco de maçã na remoção do corante catiônico azul de metileno em meio aquoso. Após sua coleta e preparação, o bagaço de maçã foi caracterizado por meio de várias técnicas, como análise elementar, espectroscopia no infravermelho com Transformada de Fourier, espectroscopia de ressonância magnética nuclear de carbono-13 no estado sólido, análise termogravimétrica e microscopia eletrônica de varredura. A área superficial específica, bem como o diâmetro médio das partículas e o pH no ponto de carga zero foram igualmente determinados. Após a caracterização, a capacidade de adsorção do bagaço de maçã foi investigada em sistema de batelada. A concentração de corante remanescente em todos os experimentos de adsorção foi estimada por meio de uma curva de calibração, utilizando-se a técnica de espectroscopia de absorção molecular na região do visível. Além disso, a influência de parâmetros experimentais, tais como concentração inicial do corante, massa de adsorvente, pH do meio, velocidade de agitação do sistema e temperatura, foi avaliada por meio da execução de planejamento fatorial. Com relação ao equilíbrio de adsorção, foi verificado que a isoterma de Langmuir foi a que melhor se ajustou aos resultados experimentais em todas as temperaturas avaliadas, apresentando valores para a constante de Langmuir (KL) e para a capacidade máxima de adsorção (qm) nas faixas 0,0951 a 0,1122 L mg-1 e 97,60 a 133,15 mg g-1, respectivamente. Do ponto de vista termodinâmico, os resultados revelaram um processo físico e espontâneo, com valores de ΔG°ads menores do que -0,59 kJ mol-1, enquanto que ΔH°ads e ΔS°ads resultaram em -19,84 kJ mol-1 e -62,72 J mol-1 K-1, respectivamente. No que se refere à cinética de adsorção, o modelo de pseudossegunda ordem foi o que melhor descreveu o processo. O estudo dos mecanismos de transferência de massa demonstrou que o processo de adsorção é controlado tanto pela difusão no filme estagnado que recobre as partículas, quanto pela difusão intrapartícula no interior dos poros das mesmas para a maior parte das condições de processo verificadas. Os valores para o coeficiente de transferência de massa através do filme estagnado (kf) situaram-se na faixa de 0,57 × 10-6 a 3,13 × 10-5 m min-1, enquanto que a constante de velocidade de difusão intrapartícula (kint) ficou compreendida entre 4,43 e 9,81 mg g-1 min-1. Por fim, o bagaço de maçã mostrou ser um bom adsorvente para a remoção do corante catiônico azul de metileno, podendo ser reutilizado em mais de um ciclo de remoção, sem perdas significativas de propriedades após o processo de regeneração utilizando etanol como solvente.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES.
The development of new technologies for the treatment of wastewater containing dyes has generated a great interest in recent years, due to increase awareness about environmental preservation, in addition to the rigidity of specific legislation. In this sense, the adsorption has been a promising technique for color removal, once it offers relatively low-cost, besides to be endowed appreciable efficiency. Considering the mentioned aspects, this study aimed to evaluate the adsorption capacity of a solid agro-industrial waste from apple juice industry (pomace) in the removal of methylene blue cationic dye in aqueous medium. After its collection and preparation, the biomass was characterized by means of several techniques, including elemental analysis, Fourier transform infrared spectroscopy, solid-state 13C nuclear magnetic resonance spectroscopy, thermogravimetric analysis and scanning electron microscopy. The specific surface area, as well as the average diameter of the particles and the pH at the point of zero charge were also determined. After characterization, the adsorption capacity of the apple pomace was investigated in a batch system. The concentration of dye in all remaining adsorption experiments was estimated using a calibration curve by means of molecular absorption spectroscopy in the visible region. Furthermore, the influence of experimental parameters such as initial dye concentration, adsorbent amount, pH of the medium, stirring rate of the system and temperature were also evaluated by a factorial design. Concerning the adsorption equilibrium, the Langmuir isotherm provided the best fit for the experimental data for all temperature evaluated, with values for the Langmuir constant (KL) and maximum adsorption capacity (qm) situated in the ranges from 0.0951 to 0.1122 L mg-¹ and 97.60 to 133.15 mg g-¹, respectively. From the thermodynamic point of view, the results revealed a physical and spontaneous adsorption process, with values lower than -0.59 kJ mol-1 for ΔG°ads, while ΔH°ads and ΔS°ads resulted in -19.84 kJ mol-1 and -62.72 J mol-1 K-1, respectively. The adsorption kinetics was better described using a pseudo-second-order model. Studies on the mechanisms of mass transfer have shown that the adsorption process is controlled by either diffusion on the stagnant film that covering the particles and intraparticle diffusion inside particle porous in the most part of experimental conditions tested. The values of stagnant film mass transfer coefficient (kf) lie within 0.57 × 10-6 to 3.13 × 10-5 m min-1 range, while intraparticle diffusion rate constant (kint) remained between 4.43 and 9.81 mg g-1 min-1. Finally, the apple pomace shown to be a suitable adsorbent for the removal of methylene blue cationic dye and can be reused for several adsorption cycles without significant properties losses after the regeneration process using ethanol as a solvent.
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Carballo-Meilan, M. Ara. "Regeneration of activated carbon by photocatalysis using titanium dioxide." Thesis, Loughborough University, 2015. https://dspace.lboro.ac.uk/2134/19065.
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The adsorption of methylene blue onto two types of commercial activated carbons, a mesoporous type (Norit CA1) and microporous type (207C) was analysed. Powdered TiO2 was mixed with the carbon and added to the dye solution to determine the influence of the photocatalyst during the adsorption process. Equilibrium and kinetics experiments were done with and without any addition of photocatalytic titanium dioxide (TiO2). Changes in capacity, heterogeneity, and heat of adsorption were detected and related to changes in the quantity of TiO2 added by evaluating the equilibrium parameter from 13 isotherm models. The influence of TiO2 on the adsorption kinetics of the dye was correlated using simplified kinetic-type model as well as mass transfer parameters. Using a formal design of experiments approach responses such as the removal of the dye, variation of pH, external mass transfer rate (KF) and intraparticle rate constant (Ki) were evaluated. Results indicated that TiO2 increased the uptake of methylene blue onto CA1, increased Ki and CA1-TiO2 interactions had electrostatic nature. In contrast, TiO2 was seen to inhibit the equilibrium adsorption for 207C by reducing its capacity. The 207C-TiO2 interaction was attributed to a specific adsorption of TiO2 on the coconut-based adsorbent, as zeta potential and pH measurements seemed to suggest. The regeneration of activated carbon using UV-C/TiO2 heterogeneous photocatalysis in a novel bell photocatalytic reactor, and in a standard-type coiled-tube photoreactor was also studied. Initially, response surface methodology was applied to finding the optimum conditions for the mineralization of methylene blue in both reactors using methylene blue as model compound and TiO2 as photocatalyst performing direct photocatalytic decolourization. Methylene blue concentration, TiO2 concentration and pH were the variables under study. Complete mineralization of the dye was achieved in the coiled-tube reactor using 3.07 mg/L of methylene blue at pH 6.5 with 0.4149 g/L TiO2. The regeneration experiments in the coiled-tube photoreactor were done using One Variable at Time (OVAT) method. The effect of the mass of TiO2 was the only studied variable. The study indicated an increase in regeneration of CA1 and a decrease in the pH during the oxidation step at higher concentration of the photocatalyst. In the case of the regeneration of 207C, the addition of TiO2 lowered the regeneration and made the suspension more basic during the photocatalytic step. However these results were not statistically significant. Experiments using the bell photoreactor were performed applying the same response surface method used in direct photocatalytic decolourization (control). The variables under study were pH, concentration of dye-saturated carbon and TiO2 concentration. The regeneration percentage was the chosen response. Low regeneration percentages were achieved (maximum 63%), and significant differences (95% confidence interval) were found between the regeneration of the activated carbons, being higher in the case of powdered CA1 as compared with granular 207C.
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Hao, Wenming. "Refining of hydrochars/ hydrothermally carbonized biomass into activated carbons and their applications." Doctoral thesis, Stockholms universitet, Institutionen för material- och miljökemi (MMK), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-107672.
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Hydrothermally treated biomass could not only be used as a fuel or a fertilizer but it can also be refined into high-value products. Activated carbons are one of those. In the studies of this thesis, four different hydrothermally carbonized (HTC) biomasses, including horse manure, grass cuttings, beer waste and biosludge, have been successfully made into activated carbons. The activated carbon materials were in the forms of powdered activated carbons, powdered composites of activated carbon and iron oxide nano-crystals, and activated carbon discs. The HTC biomasses and the activated carbons were characterized and analyzed using several methods. The biomasses were carbonized to different extent during the hydrothermal treatment, which depended on the different natures of the biomasses. The HTC biomasses were activated into powdered activated carbons by both physical activation, using CO2, and by chemical activation, using H3PO4. Full factorial design matrices were applied to design experiments and study the influence of different parameters used during both physical and chemical activation. Activated carbons with embedded iron oxide nanoparticles were synthesized through hydrothermal carbonization followed by CO2 activation. These composites had high surface areas and showed a strong magnetism, and the powders could be separated from liquid phase by applying a magnetic field. Strong and dense activated carbon discs were also prepared from powdered HTC beer waste by pulsed current processing (PCP) and a subsequent CO2 activation procedure. The potential for carbon dioxide separation from nitrogen, and methylene blue adsorption in aqueous solution, were assessed for the powdered activated carbons produced from HTC biomasses. They showed good performance in both applications.At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 1: In press.
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Góes, Mauro Cosme de Carvalho. "PALHA DA CARNAÚBA (Copernicia cerifera) COMO REMOVEDOR DOS CORANTES AZUL DE METILENO E CRISTAL VIOLETA." Universidade Federal do Maranhão, 2013. http://tedebc.ufma.br:8080/jspui/handle/tede/961.
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Previous issue date: 2013-03-13The aim of the present work was to evaluate the adsorptive capacity of carnauba straw in natura for removal of the textile dyes methylene blue and crystal violet, in aqueous solutions. Initially, the adsorbent was crushed, washed, dried at 50 ° C and sieved, so that the size of the grains come between 0.088 0.177 mm. The thermogravimetric study showed that the material begins to suffer from degradation at 150° C. The x-ray diffraction identified in the matrix and presents the amorphous with an index of crystallinity 31,80 % character study with infrared spectroscopy reveals peculiar peaks of lignocellulosic materials. For pHzpc obtained a value close to 5.5. It was observed that the pH interferes with adsorption of both dyes studied. In kinetic study, performed at 25 ° C was observed for the two dyes close to the equilibrium time of 120 min and a mechanism compatible with the linearized equation of second order (R2 = 0.9999). The model was also applied and intraparticle three stages were noted indicating that the diffusion and equilibration of the dyes with the adsorbent. The isotherms were constructed at temperatures from 25 to 55 ° C. The increase in temperature caused an increase in the adsorbed amount of crystal violet and a decrease in adsorbed amount of methylene blue. The isotherms models of Langmuir, Freundlich and Sips were applied in the evaluation of experimental results, and are best described by the Sips model (R2 = 1.0000) for the two dyes. Finally, the thermodynamic parameters showed negative enthalpy change for methylene blue (H = - 1,929.10-2 kJ mol-1), and positive for the crystal violet (H = 2,259.10-2 kJ mol-1), entropy increase and the free energy decrease with increasing temperature, for both the methylene blue as for the crystal violet.
O presente trabalho teve como objetivo avaliar a capacidade de adsorção da palha da carnaúba in natura para remoção dos corantes têxteis azul de metileno e cristal violeta, em de soluções aquosas. Inicialmente o adsorvente foi triturado, lavado, seco a 50ºC e peneirado, de modo que o tamanho dos grãos ficasse entre 0,088 0,177 mm. O estudo termogravimétrico mostrou que o material começa a sofrer degradação a partir de 150ºC. A difratometria de raio-x identificou que a matriz em estudo apresenta caráter amorfo com um índice de cristalinidade de 31,80 % e a espectroscopia na região do infravermelho revelou picos peculiares de materiais lignocelulósicos. Para o pHzpc obteve-se um valor próximo de 5,5. Observou-se que o pH interfere na adsorção dos dois corantes estudados. No estudo cinético, realizado a 25ºC, foi observado para os dois corantes o tempo de equilíbrio próximo de 120 min e um mecanismo compatível com a equação linearizada de segunda ordem (R2 = 0,999). O modelo intrapartícula também foi aplicado e três etapas foram notadas indicando a difusão e o equilíbrio dos corantes com o adsorvente. As isotermas foram construídas nas temperaturas de 25 a 55ºC. O aumento da temperatura proporcionou um aumento na quantidade adsorvida do cristal violeta e uma diminuição na quantidade adsorvida do azul de metileno. Os resultados revelaram uma quantidade máxima adsorvida igual a 0,294 mmol g-1 para o azul de metileno a 25ºC e 0,399 mmol g-1 para o cristal violeta a 55ºC. Os modelos de isotermas de Langmuir, Freundlich e Sips foram aplicados na avaliação dos resultados experimentais, sendo mais bem descritos pelo modelo de Sips (R2 = 1,000) para os dois corantes. Finalmente, os parâmetros termodinâmicos mostraram variação de entalpia negativa para o azul de metileno (H = - 1,929.10-2 kJ mol-1) e positiva para o cristal violeta (H = 2,259.10-2 kJ mol-1), aumento de entropia e diminuição de energia livre com o aumento da temperatura, tanto para o azul de metileno como para o cristal violeta.
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Wu, Zhibin, Xingzhong Yuan, Hua Zhong, Hou Wang, Guangming Zeng, Xiaohong Chen, Hui Wang, Lei zhang, and Jianguang Shao. "Enhanced adsorptive removal of p-nitrophenol from water by aluminum metal–organic framework/reduced graphene oxide composite." NATURE PUBLISHING GROUP, 2016. http://hdl.handle.net/10150/614746.
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In this study, the composite of aluminum metal-organic framework MIL-68(Al) and reduced graphene oxide (MA/RG) was synthesized via a one-step solvothermal method, and their performances for pnitrophenol (PNP) adsorption from aqueous solution were systematically investigated. The introduction of reduced graphene oxide (RG) into MIL-68(Al) (MA) significantly changes the morphologies of the MA and increases the surface area. The MA/RG-15% prepared at RG-to-MA mass ratio of 15% shows a PNP uptake rate 64% and 123% higher than MIL-68(Al) and reduced graphene oxide (RG), respectively. The hydrogen bond and pi-pi dispersion were considered to be the major driving force for the spontaneous and endothermic adsorption process for PNP removal. The adsorption kinetics, which was controlled by film-diffusion and intra-particle diffusion, was greatly influenced by solution pH, ionic strength, temperature and initial PNP concentration. The adsorption kinetics and isotherms can be well delineated using pseudo-second-order and Langmuir equations, respectively. The presence of phenol or isomeric nitrophenols in the solution had minimal influence on PNP adsorption by reusable MA/RG composite.
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Bonini, Andréa de Oliveira. "Proposta de um método de ensaio para determinação do volume de azul de metileno adsorvido pela fração fina de solos tropicais." Universidade de São Paulo, 2005. http://www.teses.usp.br/teses/disponiveis/18/18137/tde-17022006-113526/.
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No Brasil utiliza-se, como técnica de caracterização da fração fina dos solos tropicais, entre outras, o ensaio de adsorção de azul de metileno pelo método da mancha. No entanto, para alguns solos, há dificuldade na identificação do ponto de viragem, ou seja, quando há excesso de corante não adsorvido pelo solo. Assim, apresenta-se neste trabalho uma técnica alternativa para facilitar a determinação do volume de azul de metileno adsorvido por um solo, cujo método é baseado na adição em excesso de azul de metileno à amostra e na titulação de óxido-redução volumétrica (redox) do azul de metileno que não é adsorvido pelo solo. Para a avaliação do ensaio de adsorção de azul de metileno pelo método redox foram ensaiadas 85 amostras de solos e, a partir dos resultados, foram estabelecidos seus graus de atividade que, por sua vez, foram correlacionados com a previsão de comportamento dos solos dada pela MCT. Conclui-se que o procedimento de ensaio proposto é simples e a percepção do ponto de viragem na titulação do excesso de azul de metileno pelo agente oxidante permanganato de potássio é fácil para maioria dos solos, além de apresentar uma boa concordância com os resultados fornecidos pela classificação MCT, permitindo estabelecer, com razoável segurança, a atividade dos argilo-minerais presentes no soloThe methylene blue dye adsorption test (spot test) has been used in Brazil to characterize tropical soil fine fractions. Some soils, however, show difficulties in identifying the test end point, where there is excess of methylene blue in the suspension, not adsorbed by the soil. This work presents an alternative technique to determine the volume of methylene blue adsorbed by a soil, based on the addition of methylene blue in excess to the soil sample and in the determination of the amount of methylene blue that was not adsorbed by the soil through the oxide-reduction (redox) process. For the evaluation of the methylene blue adsorption test (using the redox test), 85 soil samples were tested; their activity levels were established and then correlated with the expected behavior defined by the MCT classification system. The main conclusion of the work is that the proposed method is simple and the identification of the reverse point in the oxide-reduction (redox) process is easy for a majority of soils. The process uses potassium permanganate as the oxidizing agent. It determines, with a great degree of accuracy, the activity levels of the mineral clay portions, showing a significant concordance with the results of the MCT classification system
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Franco, Dison Stracke Pfingsten. "MODIFICAÇÕES NA CASCA DE ARROZ PARA A ADSORÇÃO DE AZUL DE METILENO EM BATELADA E LEITO FIXO." Universidade Federal de Santa Maria, 2016. http://repositorio.ufsm.br/handle/1/8808.
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Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorIn this work, rice husk and its modifications were investigated as methylene blue adsorbents, using discontinuous (batch) and continuous (fixed bed) adsorption operations. The rice husk was modified through alternative treatments like; supercritical extraction with CO2, assisted ultrasound and sodium hydroxide attacks. The adsorbents were characterized through Fourier transform infrared spectroscopy (FTIR), x-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). For the batch adsorption, Langmuir and Hill models were used to describe the isotherms. From the thermodynamic perspective the adsorption was spontaneous and the adsorption capacity increases with the temperature increase. The fixed bed adsorption was optimized and adsorbents were applied in the optimal condition, then dynamic models (Thomas, BDST, Yoon-Nelson) were fitted to the experimental data to represent the breakthrough curve. In general it was found that the treatments enhanced the adsorption capacity for both process. For the batch process a pattern indicating that the NaOH rice husk (65.0 ±0.4 mg g-1) was superior to UA (58.7 ±2,1 mg g-1), SCO2 (56.4 ±0.6 mg g-1) and raw rice husk (52.2 ±1.3 mg g-1) was observed. For the fixed, the same behavior was found. The breakthrough time for the optimal conditions were 109, 240, 155 and 385 min for raw rice husk, rice husk treated with assisted ultrasound, supercritical CO2 and NaOH respectively.
Neste trabalho foi o investigado o uso casca de arroz e suas modificações como adsorvente do corante azul de metileno, em operações descontinua (batelada) e continua (leito fixo). A casca de arroz foi modificada utilizando tratamentos alternativos como: a extração supercrítica com CO2, ultrassom assistido e ataque com hidróxido de sódio. Estes materiais foram caracterizados através de espectroscopia no infravermelho por transformada de Fourier (FTIV), difração de raios-X (DRX), microscopia de varredura eletrônica (MEV) e espectroscopia de raios-X por dispersão em energia (EDS). Na adsorção em batelada, os modelos de Langmuir e Hill mostraram que a adsorção foi espontânea e que, para todos os adsorventes, a capacidade de adsorção aumentou conforme o aumento da temperatura. Para a adsorção em leito fixo foi realizada uma otimização e aplicação dos adsorventes no ponto ótimo. Foram aplicados os modelos dinâmicos (Thomas, tempo de serviço de leito, Yoon-Nelson) a fim de descrever a curva de ruptura. No geral foi possível constatar que os tratamentos utilizados melhoraram a capacidade de adsorção para ambas as operações. Para a batelada, verificou-se que a capacidade de adsorção foi na seguinte ordem: casca de arroz modificada com NaOH (65.0 ±0,4 mg g-1) > Ultrassom (58.7±2,1 mg g-1) > CO2 supercrítico (56.4±0,6 mg g-1) > casca de arroz in natura (52.2 ±1.3 mg g-1). No leito fixo o mesmo comportamento foi encontrado. O tempo de ruptura foi de 109, 240, 155 e 385 min, para casca de arroz in natura, casca de arroz tratada ultrassom assistido, CO2 supercrítico e NaOH respectivamente.
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Nonviho, Guévara. "Valorisation chimique de la biomasse oléagineuse d’origine béninoise : Lophira lanceolata et Carapa procera." Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0052/document.
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Lophira lanceolata (Ll) et Carapa procera (Cp) sont des plantes oléagineuses, peu étudiées. Au Bénin, elles sont pourtant utilisées à des fins alimentaires, cosmétiques et thérapeutiques. Cette étude vise la caractérisation de leurs graines, coques et bois. Les huiles végétales de Ll ont été obtenues par différentes méthodes dont une aqueuse traditionnelle tandis que celle de Cp l’a été par utilisation d’hexane. De façon générale, les huiles de Ll montrent un profil nutritionnel riche en acides gras polyinsaturés (>50% m/m: masse pour masse). Outre ses propriétés chimiques meilleures, celle obtenue par le procédé traditionnel est plus riche en acides gras essentiels, en composés phytostéroliques comme le lupéol et en tocols. La torréfaction et l’utilisation d’enzymes ont également permis d’évaluer l’impact de ces méthodes sur la composition chimique des graines de Ll. Quant aux graines de Carapa p., elles présentent un profil plutôt abondant en acides gras monoinsaturés, en tocotriénols (85,56% m/m) et en lanostérols (28,03%, m/m). Les tourteaux, coques et bois des deux espèces montrent une variabilité chimique en composés pariétaux (extractibles, hémicelluloses, celluloses et lignines). Une caractérisation in fine des hémicelluloses de ces parties des deux plantes a permis de montrer qu’elles sont essentiellement de type glucuronoxylanes. Les extractibles de ces plantes ont également offert une large gamme de composés à connotations industrielles et pharmaceutiques positives. Enfin, les conditions optimales de la biosorbption du bleu de méthylène sur les coques de Lophira ont également été évaluées. Cette évaluation a permis de mettre en exergue la potentielle utilisation de ces résidus agroforestiers pour rendre potables les eaux usées industriellesThe chemical composition of wild oilseeds, such as Lophira lanceolata (Ll) and Carapa procera (Cp) of Benin is mostly unknown. Yet they undergo crafted transformations for food, cosmetic and therapeutic purposes. This study aims to characterize their seeds, hulls and woods. From these crops, different oils have been extracted. One of them has been produced in rural area according to aqueous ancestral method. On the whole, oils of Ll have presented an interesting nutritional profile. They are rich in polyunsaturated fatty acids (> 50% m/m: mass for mass), especially that extracted by artisanal process. Beyond its good chemical properties, it provides essential fatty acids, phytosterols such as lupeol and more tocols compounds. Roasting and the use of enzymes have also assessed the impact of these methods on the chemical composition of LI seeds. Differently, Cp oil’s has an abundant presence of MUFA, tocotrienols (85.56% w/w) and the richest composition in lanosterol (28.03%, m/m). The seeds cakes, hulls and wood of both species showed various distributions on chemical components (extractives, hemicellulose, cellulose and lignin). The characterization of hemicelluloses from different parts of plants has shown that they are essentially glucuronoxylans type. Extractives also offered a wide range of compounds mostly appreciated for industrial and pharmaceutical purposes. The chemical composition of the shells of Lophira was rich in organic compounds such as lignin (32.13%, dry weight) so their biosorbent capacity was evaluated. They showed methylene blue good adsorption capacity in aqueous solution, which highlighted their potential use in the purification of wastewater
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Cacuro, Thiago Aguiar. "Caracterização de cinzas de queima de bagaço de cana-de-açúcar e prospecção de sua utilização como adsorvente." Universidade Federal de São Carlos, 2016. https://repositorio.ufscar.br/handle/ufscar/8941.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
The ashes resulting from the burning of sugarcane bagasse is a heterogeneous material and has various applications as an adsorbent. To enhance and assist in prospecting new applications is critical to better understand the properties of the material. In this work, its morphological, spectroscopic and elemental characterization of the ashes of sugarcane bagasse from three different plants and two different harvests and the prospect of its use as an adsorbent. The particles of the ash were separated according to their density and in order to characterize, FTIR was used in the investigation of chemical groups present in the samples, additionally to the SEM and EDS elemental and morphological characterization of the particles present in the samples. Cenospheres, spherical particles present in ash, were identified as coreshell structure, where the core is a mixed metal oxide and the shell is a layer of silicon dioxide. The correlation between the ratio of the relative abundance between the carbonyl and hydroxyl groups and the mass distribution of the granulometric extracts were used as indirect measure of the level of oxidation of the samples. The ashes’ adsorption capacity showed affinity for the methylene blue dye with an adsorption capacity of 39 mg of dye per gram of ash used, in contrast to the low adsorption of potassium chromate solution, 1.2 mg per gram of ash.
As cinzas oriundas do processo de queima do bagaço de cana-de-açúcar são um material heterogêneo e com diversas aplicações, como a adsorção. Para potencializar e auxiliar na prospecção de novas aplicações é fundamental conhecer melhor as propriedades do material. Neste trabalho foi feita esta caracterização morfológica, espectroscópica e elementar das cinzas do bagaço da cana-de-açúcar provenientes de três diferentes usinas e duas diferentes safras e a prospecção de seu uso como adsorvente. As partículas das cinzas foram separadas de acordo com sua densidade e para a caracterização foi utilizada a técnica de FTIR na investigação dos grupos químicos presentes nas amostras e MEV juntamente com o EDS para a caracterização morfológica e elementar. As cenosferas, partículas esféricas presentes nas cinzas, foram identificadas como estruturas coreshell onde o core é composto por um misto de óxidos metálicos e o shell composto por dióxido de silício. A correlação entre a razão da abundância relativa entre os grupos de carbonila e hidroxila e a distribuição mássica dos extratos granulométricos, foi usada como medida indireta do nível de oxidação das diferentes amostras. Quanto à sua capacidade de adsorção, as cinzas mostraram afinidade na adsorção do corante azul de metileno com uma capacidade de adsorção de 39mg de corante por grama de cinza usada em contraste com a baixa adsorção apresentada para a solução de cromato de potássio com 1,2 mg por grama de cinza.
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Vijwani, Hema. "Hierarchical Porous Structures with Aligned Carbon Nanotubes as Efficient Adsorbents and Metal-Catalyst Supports." Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1433350549.
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Hazafy, David. "Development of colorimetric indicators based on Methylene Blue." Thesis, University of Strathclyde, 2012. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=18932.
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Bortoluzzi, Blenda Medeiros Agostinho. "Remoção dos corantes azul de metileno e cristal violeta de Solução aquosa utilizando Epicarpo (casca) de uva Niágara rosada (Vitis labrusca) como adsorvente." Universidade Federal do Pampa, 2015. http://dspace.unipampa.edu.br:8080/xmlui/handle/riu/1420.
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Neste estudo, a Casca da Uva Niágara Rosada in natura (Vitis Labrusca), aqui denominada CUNRin, foi preparada, caracterizada e, posteriormente, utilizada como adsorvente alternativo para a remoção dos corantes catiônicos, Azul de metileno (AM) e Cristal violeta (CV) de solução aquosa. Os ensaios de adsorção foram realizados pelo processo em batelada a temperatura de 25,0 ± 1,0 ºC. Importantes parâmetros que influenciam na capacidade de adsorção como pH inicial, massa de adsorvente, tempo de contato e concentração inicial de corante foram investigados neste trabalho. A capacidade máxima de adsorção para o (AM) e (CV) foi obtida em pH alcalino (8,0 - 10,0). A quantidade de massa adsorvente necessária para maior eficiência na remoção dos corantes (AM) e (CV) foi de 400,0 mg. O tempo mínimo para estabelecer a condição de equilíbrio para o (AM) foi de 30,0 minutos, enquanto para o (CV) foi de 60,0 minutos. As cinéticas de adsorção dos corantes na CUNRin foram investigadas utilizando os modelos cinéticos não - lineares de Pseudo - primeira ordem, Pseudo - segunda ordem e Elovich. O modelo de Pseudo-segunda ordem é o que melhor descreve a cinética de adsorção para ambos corantes estudados com valores R2 próximos da unidade e baixos de valores χ2 . Estudos de equilíbrio entre adsorvente - adsorvato foram realizados através dos modelos matemáticos não - lineares de Langmuir, Freundlich e Sips. Dentre os modelos de equilíbrio estudados o modelo de Sips é o mais indicado para descrever a adsorção entre as moléculas do corante e adsorvente. Com base no modelo de Sips as capacidades máximas de adsorção obtidas foram de 110,80 ± 3,92 mg g–1 para (AM) e 93,80 ± 3,71 mg g–1 para (CV). A viabilidade da CUNRin foi investigada em efluente têxtil sintético. Os resultados obtidos mostram que a CUNRin pode ser utilizada como adsorvente alternativo para a remoção dos adsorventes (AM) e (CV) de efluentes aquosos.
In this study, Niagara grape skin Pink in nature (Vitis Labrusca), herein called CUNRin, was prepared and characterized and then used as an alternative adsorbent for the removal of the cationic dye, methylene blue (MB) and crystal violet (CV) from aquous solution. The adsorption experiments were performed by batch process temperature of 25.0 ± 1.0 °C. Important parameters that influence the adsorption capacity as initial pH, adsorbent mass, contact time and initial concentration of dye were investigated in this work. The maximum adsorption capacity for (AM) and (CV) was obtained at alkaline pH between (8.0 - 10.0). The amount of adsorbent required for efficient removal of dyes (AM) and (CV) was 400.0 mg. The minimum time to set up the equilibrium condition for (AM) was 30.0 minutes, while for the (CV) was 60.0 minutes. The kinetics of adsorption of dyes in CUNRin were investigated using non - linear kinetic models of Pseudo - first order, Pseudo -second order and Elovich. The Pseudo - second order model is what best describes the adsorption kinetics for both dyes studied with R2 values close to unity and downs of values χ2. Balance studies between adsorbent - adsorvate were performed through nonlinear mathematical models of Langmuir, Freundlich and Sips. Among equilibrium models studied the Sips model it is the most suitable to describe the adsorption of the dye molecules and the adsorbent. Based on the model Sips maximum adsorption capacity obtained were 110.80 mg g–1 ± 3.92 mg g-1 to (AM) and 93.80 mg g–1 ± 3.71 mg g-1 to (VC). The viability was investigated CUNRin synthetic textile effluent. The results obtained show that the CUNRin can be used as an alternative adsorbent for the removal of the adsorbents (AM) and (CV) of aqueous effluents.
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Joonwichien, Supawan. "Magnetic Field Effects on Heterogeneous Photocatalytic Degradation of Methylene Blue." Kyoto University, 2011. http://hdl.handle.net/2433/151897.
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Sukhapan, Jariya. "Surfactants in atmospheric aerosols." Thesis, University of East Anglia, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.251504.
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Upadhyaya, Ashraya. "Nitrogen Doped Titanium Dioxide in the Photocatalytic Degradation of Methylene Blue." ScholarWorks@UNO, 2018. https://scholarworks.uno.edu/honors_theses/120.
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Titanium dioxide(TiO2) is a stable, effective and well-known photocatalyst for degradation of pollutants. However, its practical applications are limited due to the need for energy higher than 3.2 eV, or a wavelength lower than 390 nm (high frequency waves, ultraviolet and above) hindering its ability to effectively work in the visible light region (about 400 nm to 700 nm). Nitrogen-doped TiO2 (N-TiO2) has garnered some attention as a photocatalyst as it appears to work even in the visible light region. This could allow the utilization of a larger part of the solar spectrum. This thesis presents the results of photocatalytic degradation of methylene blue (MB) carried out under simulated visible light by using TiO2 and N-TiO2(doped in the lab) to evaluate and compare their efficiencies under similar conditions.
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Edlin, Shaun Michael. "Methylene blue, spatial memory and anterior thalamic lesions relevant to amnesic disorders." Thesis, University of Canterbury. Psychology, 2011. http://hdl.handle.net/10092/6521.
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While recent studies have focused on methylene blue’s interaction with amyloid plaques and
neurofibrillary tangles in Alzheimer’s disease,!no studies have investigated the efficacy of
methylene blue in animal-lesion models of regional pathology relevant to AD. The goal of
this dissertation was to examine the effects of methylene blue on spatial memory in aged
Wistar rats with lesions to the anterior thalamic nuclei (ATN), part of an extended episodic
memory system that shows early pathology in AD and diencephalic amnesia. First, 12 ATN
rats were compared to 14 aged shams (18 to 22 months old) to assess spatial memory
acquisition in a standard water maze task (10 days). Rats in each group then received
intraperitoneal injections of methylene blue (1 mg/kg) or placebo 1 hour after each daily trial
for 10 days in which acquisition of a new platform position was examined, followed by a
probe trial 5 days later. Anterior thalamic lesions impaired initial acquisition of the reference
memory task. In the subsequent acquisition and probe trial, methylene blue treatment vs.
placebo improved spatial learning in ATN rats, but there was no effect in sham rats. These
results provide the first evidence that methylene blue may prevent the learning impairments
observed in rats with lesions to the anterior thalamus and supports methylene blue as a
potential therapeutic intervention for older humans with memory disorders associated with
injury to the ATN and the extended episodic memory system.
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Quick, William Joseph. "Laser spectroscopy of putative dyes for photodynamic therapy." Thesis, University of Sheffield, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.284387.
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Miclescu, Adriana. "Cerebral Protection in Experimental Cardiopulmonary Resuscitation With Special Reference to the Effects of Methylene Blue /." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-106831.
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SANTOS, ALINE MAGALHAES DOS. "PHOTODYNAMIC ACTIVITY OF CHLORIN E6 AND METHYLENE BLUE PHOTOSENSITIZERS ASSOCIATED WITH GOLD NANOPARTICLES SYNTHESIZED BY LASER ABLATION." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2018. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=35265@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Terapia fotodinâmica (PDT) é um tratamento médico baseado na excitação ótica de um fármaco chamado fotossensibilizador. Quando os fotossensibilizadores são expostos a luz em comprimento de onda específico, eles podem produzir espécies reativas, como oxigênio singlete, capazes de matar células próximas ao local irradiado, tais como células cancerígenas. Nanomateriais híbridos formados de nanopartículas metálicas e componentes poliméricos são investigados por seu potencial em aplicações biomédicas devido à sua habilidade de simultaneamente permitir detecção para diagnóstico e terapia (teranóstico). Graças à multifuncionalidade assegurada pelas propriedades plasmônicas das nanopartículas metálicas e atividade terapêutica dos nanotransportadores de drogas, o encapsulamento de nanopartículas de ouro (AuNPs) envolvidas por polímeros biocompatíveis se tornaram um caminho fascinante para testar a terapia fotodinâmica, com a grande vantagem de prevenir efeitos de agregação em condições biológicas. Essa dissertação tem enfoque na estabilização e atividade fotodinâmica de um nanomaterial híbrido constituído de AuNPs sintetizadas em água por ablação a laser pulsado. O copolímero Pluronic F-127 foi utilizado como componente polimérico para estabilizar as nanopartículas. A produção de oxigênio singlete pelos fotossensibilizadores clorina e6 e azul de metileno foi estudada em ausência e em presença das AuNPs, utilizando 1,3-difenilisobenzofurano (DPBF) como sonda molecular. A reação específica de DPBF com oxigênio singlete modifica seu espectro de absorção na faixa visível, permitindo obter taxas de produção da espécie citotóxica. As amostras foram irradiadas com um LED emitindo em 650 nm e os espectros de absorção foram monitorados como função do tempo durante a irradiação. Foram obtidas taxas de fotodegradação dos fotossensibilizadores e rendimento quântico de produção de oxigênio singlete nos diferentes casos.
Photodynamic therapy (PDT) is a medical treatment based on the optical excitation of a drug, called photosensitizer. When photosensitizers are exposed to light of specific wavelength, they can produce reactive species, such as singlet oxygen, capable of killing cells close to the irradiated site, such as cancer cells. Hybrid nanomaterials, comprising metallic nanoparticles and polymeric components, are investigated for their potential in biomedical applications due to their ability to simultaneously allow detection for diagnosis and therapy (theranostic). Thanks to the multi functionality assured by the nanoparticle plasmonic properties and therapeutic activity of the drug nanotransporters, the encapsulation of gold nanoparticles (AuNPs) wrapped by biocompatible polymers has become an attractive way to test photodynamic therapy, with the great advantage of preventing effects of aggregation under biological conditions. This dissertation focuses on the stabilization and photodynamic activity of a hybrid nanomaterial composed of AuNPs synthesized in water by laser ablation. The copolymer Pluronic F-127 was used as a polymeric component to stabilize the nanoparticles. The production of singlet oxygen by the photosensitizers chlorin e6 and methylene blue was studied in the absence and presence of AuNPs using 1,3 diphenylisobenzofuran (DPBF) as a molecular probe. The specific reaction of DPBF with singlet oxygen modifies its absorption spectrum in the visible range and allows to obtain rates of cytotoxic species production. Samples were irradiated with a LED emitting 650 nm radiation and the absorption spectra were monitored as a function of time during irradiation. Rates of photosensitizers degradation and quantum yields of singlet oxygen production were obtained in different cases.
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Amba, Akanimo Emene. "Biosorption of selected heavy metal ions and methylene blue from aqueous solution using chemically treated Luffa cylindrica." Thesis, University of Sheffield, 2018. http://etheses.whiterose.ac.uk/21330/.
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Chang, Kai-Chun, and 張凱鈞. "Fabrication of Functional Graphene for Methylene Blue Dye Adsorption." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/5pzq3m.
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碩士國立臺灣海洋大學
光電科學研究所
107
In this paper, we use the epidermis of sunflower seed hulls（ESSH）to form a filter material with graphene composition after high temperature vacuum carbonization. We call it functional graphene, and it has been found to have adsorption efficiency in methyl blue（MB）wastewater. When the ESSH are carbonized by high temperature vacuum, graphene with defects is produced. The formed defect graphene is composed of part of graphene structure and disordered carbon. As we know, the electronic configuration of graphene has π bond that according to the literature, its π-electron has a contaminant that adsorbs cations. Through the measurement of this experiment, it can be found that the functional graphene has better adsorption efficiency than the filter material in the general carbonization process. We modify the chemical vapor deposition process of growing graphene on the copper sheet from the inorganic carbon source. In addition, we use the copper wire as a catalyst to mix with the ESSH, which produce functional graphene. Under the carbonization in the high temperature vacuum furnace, the optimum process conditions are as follows: heating at 200°C to 400°C for 1.5 hours and 1000°C for 15 minutes then cool down to room temperature. From Raman spectroscopy, we found the experimental sample has graphene-specific aromatic resonance signal (2D). I2D / IG = 0.34 is known from the literature. It is expressed as more than five layers of graphene. And by energy dispersive X-ray spectroscopy (EDS), we can get a product with a carbon content ratio of up to 85%. In the carbonization process, the non-carbon elements in the living body can be effectively removed, and the residual non-carbon elements are non-volatile sulfur and magnesium elements. Through the nitrogen adsorption experiment, the surface area of the ESSH (experimental) after vacuum high temperature carbonization can obtain a very high specific surface area of 305.4789 m2 / g. In the experimental, the copper wire is used as a catalyst, the carbon is arranged in a graphite state and carbonized at a vacuum high temperature to effectively remove non-carbon elements, and a relatively irregular graphene stack can be grown. This process can cause more pores and surface area. The experimental sample was observed under Scanning Electron Microscope and found that special fluff shape on the surface that indicating the basis for increasing the specific surface area. In the methyl blue adsorption experiment, the experimental group was found to have excellent adsorption efficiency. The experimental approached the Langmuir isotherm adsorption model. Therefore, the adsorption behavior of the experimental is monolayer adsorption for MB, and the material at the adsorption point has no interaction force, so the adsorption capacity should be proportional to the specific surface area. The experimental maximum MB adsorption capacity was determined as qmax = 211.416 mg/g, and the control2 had qmax = 16.116 mg/g and the BET specific surface area was 305.4789 m2/g (experimental) was about 38 times for 7.9265 m2/g (control2). A positive correlation is given, which also confirms the conclusions defined by the Langmuir isotherm adsorption model. Keywords： graphene, adsorption, methyl blue
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Su, Yu-Ren, and 蘇育任. "Adsorption of Methylene Blue and Fipronil by Commercial Activated Carbons." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/72001824736892787095.
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Pan, Xin-Hong, and 潘信宏. "Study of the Adsorption Efficiency of Activated Bentonite for Methylene Blue." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/62539394998630344396.
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碩士東南科技大學
防災科技研究所
99
The objective of this study is to activate bentonite by sulfuric acid to enhance the adsorption performance of bentonite. Several Experiments were carried out, including: 1. To measure the specific surface area for both raw bentonite and activated bentonite by using brunauer emmett teller (BET) measurements, 2. To observe the difference of bentonite surface by using scanning electron microscopy (SEM), 3. To understand the characteristics of adsorption for on thermodynamics and kinetics Activation of the bentonite for both raw bentonite and activated bentonite by using basic dye Methyleneblue (MB) as a solute. The result indicated that the surface area of 76.11 m2/g was for the raw bentonite whereas the activated bentonite had the surface area of 116.131 m2/g. From SEM figures, we found that the surface of bentonite after activation significantly increased the fold. It was inferred that Fe3 +, Ca2 +, Mg2 +, Na + and other cations in montmorillonite crystal layer of bentonite had been replaced by hydrogen ions. From experiments of kinetic study, the adsorption rate constants for MB bentonite were increased by temperature after bentonite was activated whereas they were not increased by pH value and concentration of MB. From experiments of thermodynamic study, adsorption reactions of MB for both raw bentonite and activated bentonite were irreversible and endothermic reactions, and they were physical adsorptions. The results also showed that the adsorption reactions of MB for raw bentonite was a non-spontaneous reaction (G0> 0) whereas they were spontaneous reaction (G0 <0) for activated bentonite. Regarding to isotherm experiments, the results indicated that the phenomena of adsorption for raw bentonite could be described by Langmuir theory whereas they were more suitable for Freundlich theory for activated bentonite.
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SYU, HAO-SIANG, and 許皓翔. "Study on the synthesis of CaCO3@PSS for adsorption of Methylene blue." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/8cc97y.
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碩士明志科技大學
化學工程系碩士班
107
In this study, polystyrene sulfonic acid (PSS) was used to mediate the production of mesoporous calcium carbonate vaterite, and only a simple synthesis method was used to investigate the adsorption characteristics of the new composite material CaCO3@PSS for methylene blue. This study included the finding from the XRD pattern that as the PSS addition ratio increased, the vaterite ratio increased, which in turn reduced the non-porous calcite crystals. In the BET experiment, although the specific surface area(30m2/g) is lower than other mesoporous materials such as activated carbon and SBA-15. It is advantageous for the adsorption of methylene blue from the adsorption isotherm, and the higher the initial concentration of methylene blue, the higher the adsorption amount. In 50ppm methylene blue with 50 mg of adsorbent, the adsorption amount can reach 127 mg/g. The formation of spherical particles is indicated by SEM and TEM images, indicating that the addition of PSS is important for the formation of vaterite. Under the coating of PSS, calcium carbonate can maintain the crystal state of vaterite in water for a period of time, but it is found by XRD pattern that it has been partially converted into calcite crystals after standing for a while in water. After more than one month, it has completely no ball meteorite. However, compared to the sample without PSS, the crystal form of vaterite could not be synthesized at all by simple binary solution synthesis.
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Du, Jia-Jin, and 杜佳瑾. "Effects of The Adsorption of Methylene Blue in Dye Solutions Using Waste Eggshell." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/22480105413624296904.
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碩士國立屏東科技大學
環境工程與科學系所
99
In this study, waste eggshell was used as an adsorbent for the treatment of methylene blue in dye solutions. The initial concentration, particle size, adsorption time, pH and the adsorption dosage using eggshell were investigated to find the best conditions for the improvement of eggshell recycling efficiency.The number of pores was reduced after adsorption observed by scanning electron microscopy (SEM). The calcined eggshell crystal showed no change in the pore size. Fourier transform infrared spectroscopy (FTIR) showed no functional groups changed before and after the adsorption. The X-ray diffraction (XRD) analysis of eggshells before and after adsorption remained the same as the calcite (CaCO3). The calcined eggshell is calcium oxide (CaO). The process of adsorption equilibrium was reached within 150 minutes. The absorption rate was up to 70 % using initial concentration of 10 mg / L and 1g of eggshell. Little effect of adsorption was showed through the sieved eggshell. The adsorption of eggshell membrane was up to 80% . The amount of eggshell should be adjusted based on different concentrations of MB. The adsorption temperature, pH, RPM has little effect on the adsorption rate. In conclusion, eggshell can be an effective method for the adsorption of MB.
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Lkhagvajav, Jargalmaa, and 李佳格. "Comparative Adsorption of Methylene Blue from Aqueous Solution onto Activated CarbonBased on Different Modifiers." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/buat5u.
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碩士國立勤益科技大學
化工與材料工程系
107
In a world where demands for freshwater are ever growing, and where limited water resources are increasingly stressed by over-abstraction, pollution and climate change, neglecting the opportunities arising from improved wastewater management is nothing less than unthinkable. It is estimated that well over 80 percent of wastewater worldwide (over 95 per cent in some developing countries) is released into the environment without treatment. With rising water scarcity in many regions, this is changing, and we see increasing recognition of the importance of wastewater collection, treatment and reuse. The 2017 World Water Development Report shows that improved wastewater management is as much about reducing pollution at the source, as removing contaminants from wastewater flows, reusing reclaimed water and recovering useful by-products. Waste water recycling is one of the most sensible and winning options for promoting water sufficiency and it can range from simple home methods to sophisticated industrial wastewater filtration systems. The aim of the present research is to removal of methylene blue by one of the physical treatment method of adsorption from industrial wastewater. In this research, a carbon adsorbent material had been obtained by carbonization and activation of the waste cation-exchange resin. Activated carbon (AC) is a very well known material for adsorption of dye products from wastewater. However one of the disadvantage of AC adsorbent material is high cost. Therefore, In this study used waste ion-exchange resin to produce carbon adsorbent material. Chemical activation of the carbon adsorbent material, using nitric acid as dehydrating agent, is adopted for activated carbon preparation and main process parameters (such as acid concentration, and impregnation ratio) are varied to optimize the best conditions. The activated carbon prepared under the optimal conditions is then fully characterized considering its adsorption properties as well as its chemical structure and morphology. The results show that the most efficient adsorbent is that obtained under the following optimal conditions: an acid concentration equal to 5M HNO3, and carbonization temperature of 500 ℃. 0.5 g of AC modified with 5M concentration of HNO3 showed 99.6% MB removal efficiency after 1h treatment process. And concentration of MB was 30 ppm. Langmuir and Freundlich isotherm regression constant R2=0.87 and R2=0.88 proved that adsorption of MB by AC modified by 5M concentration of HNO3 was favorable sorption process.
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Kuo, Jui-Yen, and 郭睿嬿. "Adsorption of Methylene Blue, Acid Blue 25, and Disperse Blue 14 from Aqueous Solution Using Sediment Obtained from Drainage Canal in Industrial Area." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/17096191094498208662.
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碩士國立宜蘭大學
環境工程學系碩士班
104
The dye wastewaters usually contain high chroma and high chemical oxygen demand. Several natural and synthetic materials have been employed as sorbents for treatment of these waters. For example, activated carbon has been the most extensively applied, but its high cost limits a large-scale application. In this study sediment obtained from drainage canal in industrial area was utilized for removal of cationic methylene blue (MB), anionic acid blue 25 (AB 25), and nonionic disperse blue 14 (DB 14) from aqueous solutions. Organic matter content of sediment was about 29 % and carboxyl was the most important functional group for dye sorption. For preventing the dissolution of Cu, Ni, and Zn from the sediment, the sorption of dyes should be conducted at a condition higher than pH 3.0. Maximum removal of MB was observed at pH 8.0 and this removal increased with increasing temperature. The MB sorption was well described at 10℃ with Dubinin-Radushkevich and Temkin sorption isotherms, but it showed good compliance with Langmuir isotherm only at 55℃ as well as fitted Freundlich isotherm well at 25 ℃ and 40 ℃. Maximum adsorption amount (Qm) at 55 ℃ was 66.3 mg g^1. Gibb free energy (ΔG^o), reaction heat (ΔH^o) and the entropy (ΔSo) were -33.06 kJ mole^1, 7.45 kJ mole^1, and 124.81 J mole^1K^1, respectively. A pseudo-second order sorption kinetic model described the kinetics of sorption of MB onto sediment successfully at different operation parameters (i.e., temperature, initial MB concentration, and particle size). The rate constant (k2) of MB sorption was 0.00539 g mg^1min^1, and activation energy (Ea) was calculated to be 34.886 kJ mole^1. According to values of ΔG^o, ΔH^o, and Ea, the sorption of MB was a spontaneous, endothermic, and physical-sorption reaction. The removal of AB 25 decreased with an increase in temperature and its maximum sorption occurred at pH 3.0. The sorption of AB 25 was only well described with Temkin isotherm (R2= 0.799～0.990). However, the sorption of DB 14 was not complied with any isotherm. The removal percentages of the three dyes at 300 ppm and 25 ℃ was in the following order: AB 25 (87.8 %)＞MB (81.7 %)＞DB 14 (77.5 %).
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Chiu, Chun-Chieh, and 邱俊傑. "Adsorption of methylene blue and hexavalent chromium by activated carbon preparation from Tectona grandis sawdust." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/2wczm5.
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碩士中原大學
環境工程學系
106
The objective of this study was to use Tectona grandis chips to produce activated carbon through two steps. First step, the wood chips are carbonized by hydrothermal synthesis. Second step, the samples were activated by two activation agents including K2CO3 and ZnCl2 with various ratios of wood against activation agent. The obtained samples were characterized by SEM, FTIR, XPS and BET surface area. Then, the activated carbons were used to adsorb MB and Cr(VI) under the various pH conditions. The synthesized adsorbents are expected to produce adsorbents with the high adsorption efficiency to remove contaminants and to achieve the purpose of reusing forest waste resources. From the results of SEM analysis, the activated carbons possess the rough surface and obvious pore volume. BET surface analysis indicated the surface area of WAC is 792 m2 g-1 and the surface area of ACK1075 and ACZ1175 is increased to 1013 m2 g-1 and 1757 m2 g-1 after chemical activation. The main element composite of the carbons involved C and O atoms through XPS analysis. The result in FTIR spectra demonstrated the primary functional groups are OH,C-O, C=C,C≡C and COOH. The results show that active carbon of ACK1075 and ACZ1175 can obtain the best adsorption efficiency for methylene blue and Cr(VI). The adsorption capacities of methylene blue for ACK1075 and ACZ1175 were 1429 mg/g and 1667 mg/g, respectively. The adsorption capacities of Cr(VI) at pH=3 for ACK1075 and ACZ1175 were 114 mg/g and 147 mg/g respectively.
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Hsieh, Siang-Jhen, and 謝享真. "Preparation, Characterization and Kinetics of Adsorption and Degradation of Methylene Blue of rGO/CS/ZnO Nanocomposite." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/07264539458515700214.
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碩士國立高雄師範大學
化學系
102
In recent years, graphene, with many excellent properties, has affected a lot of research attentions. Studies about graphene or graphene oxide-based composites have been widely developed and applied, such as the synthesis of chitin/chitosan-based graphene oxide–ZnO hybrid composites for better properties. However, recent studies had not yet carried out for composite materials of graphene-based chitosan – ZnO, so our research was focused on the rGO / CS / ZnO composite. In order to identify rGO / CS / ZnO composite, we used FT-IR spectroscopy, X-ray powder diffraction, UV-Vis spectroscopy, and thermogravimetric analyzer to analyze the composite. In FT-IR, XRD and UV-Vis spectrums show that composite is not only successfully synthesized, but also observed that the nanocomposite has good heat resistance. According to literatures over the past few years, some people had studied about kinetics of adsorption of methylene blue of GO/ZnO, GO/Chitosan and other graphene-related composite material. Other people had used light at specific wavelength to take degradation experiments and explored the kinetics of photodegradation. In this study, the experimental data can be well fitted with the Langmuir isotherm equation. Kinetic studies show that adsorption process followed the second order reaction model. Until the adsorption reactions reach equilibrium, altering amounts of composite materials at 365nm wavelength in light degradation experiments. The photocatalytic degradation of Methylene blue by the rGO/CS/ZnO composite under visible light obeys first order kinetics.
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Torano, Aniela Zarzar. "Chemical Modifications of Hollow Silica Microspheres for the Removal of Organic Pollutants in Simulated Wastewater." Thesis, 2017. http://hdl.handle.net/10754/623473.
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Aqueous industrial effluents containing organic pollutants, such as textile dyes and crude oil, represent environmental and human health concerns due to their toxicity and possible carcinogenic effects. Adsorption is the most promising wastewater treatment method due to its efficiency, ease of operation, and low cost. However, currently used adsorbents have either high regeneration costs or low adsorption capacities. In this work, new organic/inorganic hybrids based on hollow silica microspheres were successfully synthesized, and their ability to remove Methylene Blue from wastewater and crude oil from simulated produced water was evaluated.
By employing four different silanes, namely triethoxy (octyl) silane, triethoxy (dodecyl) silane, trichloro (octadecyl) silane, and triethoxy (pentafluorophenyl) silane, hydro and fluorocarbons were grafted onto the surface of commercially available silica microspheres. These silica derivatives were tested as adsorbents by exposing them to Methylene Blue aqueous solutions and synthetic produced water. Absorbance and oil concentration were measured via a UV/Vis Spectrophotometer and an HD-1000 Oil-in-Water Analyzer respectively. Methylene Blue uptake experiments showed that increasing the adsorbent dosage and decreasing initial dye concentration might increase adsorption percentage. On the other hand, adsorption capacities were improved with lower adsorbent dosages and higher initial dye concentrations. Varying the initial solution pH, from pH 5 to pH 9, and increasing ionic strength did not seem to have a significant impact on the extent of adsorption of Methylene Blue. Overall, the silica derivative containing aromatic functional groups, Caro, was proven to be the most effective adsorbent due to the presence of π-π and cation-π interactions in addition to the van der Waals and hydrophobic interactions occurring with all four adsorbents. Although the Langmuir Model did not accurately represent the equilibrium data, it produced consistent maximum adsorption values and adsorption equilibrium constants. Preliminary experiments demonstrated the potential to recover and reuse the silica microspheres by washing with NaOH and organic solvents.
The preferential adsorption of oil micro-droplets onto the surface of functionalized hollow silica microspheres was evidenced. However, preparing synthetic produced water that was stable enough to carry out kinetics experiments remained a challenge.
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Russell, George 1983. "Detection and Quantification of Expansive Clay Minerals in Geologically-Diverse Texas Aggregate Fines." Thesis, 2012. http://hdl.handle.net/1969.1/148418.
Full textAbstract:
Expansive clay mineral contamination of road aggregate materials in Texas is a persistent problem. Hydrous layer silicate minerals - particularly smectites - in concretes are associated with decreased strength and durability in Portland cement and asphalt concretes. The Texas Department of Transportation (TXDOT) and Texas A&M Transportation Institute (TTI) evaluated the methylene blue adsorption test for its potential to identify and estimate quantities of expansive clays in aggregate stockpiles.
Clay mineral quantification was completed for 27 geologically-diverse aggregate materials from Texas, Oklahoma, and Arkansas. X-ray diffraction analysis (XRD) of separated clays on glass was conducted, and NEWMOD was utilized to model the resulting diffraction patterns. Methylene blue adsorption (MBA) and cation exchange capacity (CEC) of clay fractions (< 2µm) and -40 mesh screenings (< 400 µm) were determined for most aggregates.
Many of the aggregates exhibited significant quantities of expansive clay minerals such as smectite, which are linked to deleterious performance properties in concretes. While the majority of aggregates were derived from crushed limestone or calcareous river gravel parent materials, severalexhibited uncommon origins and unusual clay mineralogy. Due to the relatively low number of aggregates tested and diverse geological origins of the different aggregates,it proved difficult to formalize any conclusions abouttrendsbetweenthedifferent aggregate performance properties.
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Chan, Yen-Chuan, and 詹晏權. "Removal of methylene blue using manganese oxide." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/34007912157776652868.
Full textAbstract:
碩士明志科技大學
生化工程研究所
99
This research is about methylene blue (MB) removal mechanism with manganese oxide at different oxygen concentrations (opened-container, nitrogen aeration, oxygen aeration) and pH values. Use inductively coupled plasma (ICP) to analysis dissolved manganese ion, and UV/Vis spectrometer all-wavelength analysis, high performance liquid chromatography-mass spectrometer (HPLC-MS) to analysis the reactive intermediates and final products qualitatively. Then, study the roles of adsorption mechanism and manganese oxide with data results. As a result, the ICP data showed that pH4 had the highest dissolved manganese ion concentration, and the UV/Vis all-wavelength scan result indicated that after manganese oxide react with methylene blue, there was a blue-shift appears at the acidic environment, which was determined as thionin (Th). Furthermore, manganese oxide is the major oxidant at pH4 in all three different oxygen concentrations. However, compare the different oxygen concentrations with all-wavelength analysis in the nitrogen aeration of pH6 system, the adsorption peak increases with time, which was speculated that the initial state of manganese oxide was adsorbed and processed oxidation in the final state. Under the alkaline condition, dissolved manganese ion concentration decreases after the reaction, and unable to find efficient color removal with the all-wavelength analysis. Particularly, the methylene blue specific absorbing peak is 665nm and had noticeable decrease trends at pH8 and pH10. In the meantime, the HPLC-MS analysis results showed that there is only one single reactive intermediate, thionin(228) in the environment of pH6 and pH 8 after manganese oxide react with methylene blue. However, there were many reactive intermediates, such as azure A, azure C and the final dye thionin in pH4 and pH6 environments that proved the electron transfer phenomenon between dye molecules and manganese oxide. In summary, the main reaction mechanics of methylene blue are: (1) adsorption and the fall off stage of auxochrome, (2) further degradations of reactive intermediates.
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Wrubel, Kathryn Marigrace. "Memory improvement with the metabolic enhancer methylene blue." Thesis, 2006. http://hdl.handle.net/2152/2671.
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Huang, Shuang-Rung, and 黃炫榕. "Photodynamic Inactivation of Enterovirus 71 with Methylene Blue." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/34332924197741397273.
Full textAbstract:
碩士國立成功大學
微生物及免疫學研究所
95
Photodynamic treatment (PDT) has been applied to destroy cancer cells and a variety of microorganisms including bacteria and viruses by combining light and photosensitizing agents in an oxygen-rich environment. Certain photosensitizing agents can bind strongly with nucleic acids and generate reactive oxygen species after activation upon illumination, which is responsible for the disruption of viral structures and viral nucleic acid-protein cross-linkage. In this study, we have tested whether methylene blue (MB), the most widely used photosensitizing agent, is feasible for photodynamic inactivation of enterovirus 71 (EV71), a non-enveloped virus belonging to the Picornaviridae family, which can cause severe central nervous system infections and has neither anti-viral drug nor vaccine available. EV71 is transmitted through oral-fecal route and resistant to 70 % alcohol disinfection. We demonstrated that EV71 on solid surface could be photodynamically inactivated by illumination with visible light in the presence of MB. Photodynamic inactivation of EV71 in suspensions by MB showed dose- and light-intensity-dependent manners. Illumination without MB or MB alone in the dark and preactivation of MB showed no such effect. The optimal condition for photoinactivating EV71 required a light intensity of 200 J/cm2 and MB of 0.1 mM. This PDT condition could also inactivate other enteroviruses, including poliovirus 1, cosackievirus A2, A3, A16, and B3. Western blot and reverse-transcriptase PCR analysis indicated that the viral proteins and genome were broken after PDT. Thus, protein and genome damage appears to be involved in photoinactivation of EV71. In conclusion, PDT can inactivate EV71 efficiently and it may provide a method of eliminating environmental contaminated source of EV71 to prevent EV71 infections.
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He, Jheng-Wu, and 何振武. "A Study For Synthesizing Chitosan/TiO2 Material to Remove Methylene orange & Methylene blue." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/03728858497706903096.
Full textAbstract:
碩士國立雲林科技大學
環境與安全工程系碩士班
97
In recent years, research for Chitosan/TiO2 many different ways, this study use of sol-gel method to prepare, but also the use of Taguchi method of preparation of composite materials Chitosan/TiO2, and then applied to anionic dye Methylene orange and the cationic dye Methylene blue to compare their photocatalytic effects, estimation and recycling experiments. Taguchi method of preparation of Chitosan/TiO2 composite materials to assess the effects of various factors, and the types of photocatalyst is the greatest impact, to enhance the effect of removing the conditions when the priority control. From the ANOVA in the case were that the photocatalyst type, curing solution concentration, washing liquid pH, amount of emulsifier, amount of acetic acid, EDTA concentration, mixing time and the substrate, of which types of variation Photocatalyst and the proportion of the most significant contribution to 38.28% for the strongest. Projections based on the formula may to absorb 25.91, the projection of its removal rate is about 15.18%, unit volume of adsorbent for one hour to remove 9.28μmol/g. It can be found after the photocatalytic removal of this material was significantly higher than adsorption, the first 30 minutes of adsorption, relatively strong then decreasing and the photodegradation increasing steadily. Adsorption would be equilibriable after 180 minutes, and the saturation adsorption capacity of MO and MB were 0.30 and 4.91 (mg/g), respectively. MO and MB dye were more closer to the Freundlich isotherm model with linear regression R2 of 0.889 and 0.976.
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Li, Hung-Chih, and 李鴻志. "Rapid removal of methylene blue by Fe-filled CNTs." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/18760029254746878391.
Full textAbstract:
碩士國立清華大學
材料科學工程學系
101
Carbon nanotubes (CNTs), due to surface ring currents and high specific surface area, are often used as absorbing materials and energy storage devices. This thesis focuses on use of Fe-filled CNTs as adsorbents for simultaneous filtering of methylene blue in solution. Fe-filled CNTs are made by pyrolysis of ferrocene and core structure, as revealed by XRD, SEM and TEM, is dominated by α-Fe, along with Fe3C and Fe2O3 as minority. SQUID indicate that Fe-filled CNTs are of ferromagnetic and saturation magnetization reaches a value as high as 0.85emu. UV-Vis spectrometric data confirm reduced concentration of methylene blue by Fe-filled CNTs and the adsorption mechanism resulting from the defects of hexagonal carbon network through Raman spectrometer.
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Ho, Ren-Yu, and 何任于. "Electroanalysis of Methylene Blue Using Clay-modified Electrode Method." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/02233664399812084453.
Full textAbstract:
碩士國立中興大學
土壤環境科學系所
99
Methylene blue was wildly used as a redox indicaor and photosensitizer in analytical chemistry, and that could be a model compound of mobilization and transportation in the environment. We studied electrochemical behavior of methylene blue using the technology of of eletroanalysis coupled with clay-modified electrode, and changed scan rate to study the migration of methylene blue in clay films. The results indicated the redox amounts of methylene blue were apparently affected by scan rate, and the cyclic coltammgrams were also affected by different layer charge of clay minerals. Redox potential shifted to more positive potential when methylene blue coexisted with hydroquinone in the electrolyte, and redox potential also shifted to more positive potential when actinomyces was added to methylene blue solution. Lower peak currents were detected in the methylene blue solution using smectite-modified electrode and higher peak currents were detected using other modified electrodes. The results showed hydroquinone and actinomyces could affect telectrochemical behavior of methylene blue in the clay films and the peak currents of methylene blue were apparently affected by smectite-modified electrodes.
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Chao, Wen-huang, and 趙紋凰. "Methylene blue degradation on polymer-coated copper oxide surfaces." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/a4t4b2.
Full textAbstract:
碩士國立中山大學
化學系研究所
103
Because of the discharge of industrial wastewater, water pollution caused by organic dyes has been a serious problem. Not only seriously affect the living environment but also threaten human health. Hydroxyl radical is an excellent oxidant which can effectively degrade the organic dye. We use copper oxide and hydrogen peroxide as a Fenton-like agent to produce hydroxyl radical, and degrade methylene blue known as an organic pollutant. In the first part of the experiment, we synthesized CuO and CuO@polymer as Fenton-like agent to decompose hydrogen peroxide, the polymer include polyethylene glycol, polylysine, and polydopamine, and the UV-Vis spectrometer monitor the reaction. We find the optimal reaction conditions by adjusting the initial pH of the solution. The results show the optimum reaction condition was pH value between 3 to 9. The decolorization degree of methylene blue at pH 4 almost reached 100% by the agent CuO@PDA after 10 minutes. In the kinetic analysis of CuO, CuO @ PEG and CuO @ Polylysine, the reaction can divide into to two part of pseudo first-order reaction by 10 min, and the CuO@PDA is a pseudo second-order reaction before 20 min. In the second part of the experiment, we synthesized CuO@Agar、CuO@Agar-Polymer to combine the adsorption technology and the Fenton-like reaction to degrade methylene blue, the polymer include polyethylene glycol, polylysine, and polydopamine. We find that the optimal decolorization conditions is to use CuO@Agar-PDA as agent at pH 4, which can decolorize over 90% of methylene blue over 60 min. In the kinetic analysis of CuO@Agar、CuO@Agar-Polymer, the reaction can divide into to two part of pseudo second-order reaction by 30 min.
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Hsu, Che-Hao, and 許哲豪. "Gold Nanoparticles Conjugated with Methylene Blue for Photodynamic Therapy." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/94247580990683746063.
Full textAbstract:
碩士國立臺灣大學
化學工程學研究所
102
Photodynamic therapy (PDT) mainly involves cellular uptake of photosensitizer (PS) and excitation of light at specific wavelength to induce generation of reactive oxygen species (ROS) inside the targeted cells. This approach usually suffers from two main deficiencies: dark toxicity of PS and poor selectivity of cellular uptake between targeted cells and normal tissues. In this work, a known effective PS, methylene blue (MB) which can be excited by 660 nm red light source was chosen. Hela cells were used as targeted cells for PDT. To address obstacles in PDT, the MB conjugated Au nanocomposites were prepared via a hydrothermal synthesis method following by an intermolecular interaction between a poly styrene-alt-maleic acid (PSMA) layer on the Au nanoparticles (AuNPs) and MB. The structure and optical property of MB-AuNP conjugate were characterized by UV-visible spectrometer, transmission electron microscopy (TEM), X-ray diffraction pattern, and zeta-potential analysis. Furthermore, generation of ROS from MB-AuNP conjugate after excitation of 100 mW hand-held laser at 660 nm wavelength was detected by using 9, 10-Anthracenediyl-bis(methylene) dimalonic acid (ABDA). Results indicated that the MB-AuNP conjugate was successfully prepared by wet-chemistry reaction since the optical property of MB was remained after conjugation. Then toxic effect of MB-AuNP conjugate on Hela cell was examined. With a single 4 min hand-held 100 mW laser treatment, cell works proved that AuNPs as goodness carrier could effectively reduce the cell toxicity of MB and still remain the PDT efficiency. Moreover, transferrin (Tf) was grafted on the particles via EDC/NHS reaction and followed by MB attachment as Tf-MB-AuNP conjugate to enhance the selectivity of cellular uptake between cancer cells (Hela cell) and non-malignant cells (3T3 cell, fibroblast). Atomic absorption spectroscopy (AA) was used for cellular uptake quantification. In vitro ROS generation was also monitored by 2′, 7′-Dichlorofluorescin diacetate (DCFH-DA). It was shown that Tf could effectively promote cancer cell targeting. In addition, Tf-MB-AuNP was proved that could enhance PDT efficiency significantly in cell works. Finally, cell death pathway was found to be mainly apoptosis by Annexin V-FITC/PI staining. We proposed that by applying this biocompatible and cancer cell targeting Tf-MB-AuNP conjugate for PDT treatment could simultaneously reduce dark toxicity of MB and enhance the photodynamic therapy efficiency. This multi-functional AuNP could provide a less harmful alternative for PDT in cancer treatments.
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Huang, Li-Ming, and 黃麗名. "Study of photodegradation of methylene blue by Au-modified titania." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/76842868953375255200.
Full textAbstract:
碩士東海大學
環境科學與工程學系
101
Gold-modified TiO2 nano photocatalysts were prepared by sol-gel process using Au chloride trihydrate as a main component. Parameters include dosage of Au, methylene blue concentrations, reaction time, reaction temperature, and pH. The catalysts were characterized using SEM, TEM, XRD, BET surface area, UV-Vis spectrophotometer and TOC analyzer. The results show that titania exists as anatase phase after 500oC calcination. The SEM and TEM images show that the catalysts particle size is approximately 20 nm. The UV/Vis absorption spectra indicate that the Au-modified TiO2 can absorb more visible light in blue region. The results of photo-degradation show that the photocatalytic activity is very dependent on Au dosage. Higher concentration of methylene blue is associated with more degradation in terms of mole MB. The greatest photocatalytic destruction of methylene blue is observed at a water solution pH 5.7.
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Huang, Bo-syuan, and 黃柏軒. "PHOTOCATALYTIC DEGRADATION OF METHYLENE BLUE BY BROOKITE/ANATASE TiO2 MIXTURE." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/84195633333838578149.
Full textAbstract:
碩士大同大學
化學工程學系(所)
101
The brookite-TiO2 was prepared with TiCl4 as the precursor and the hydrolysis-TiO2 was prepared with TNBT as the precursor by hydrolysis process. Both photocatalysts were characterized by diffuse reflectance spectra (DRS), spectroscopic X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray microanalyses (SEM) and Brunauer-Emmett-Teller sorptometer (BET). The XRD results show that the prepared brookite-TiO2 by hydrolysis method, dried at room temperature (B-RT) and heat treatment at 100oC (B-100) for 2 hrs in an oven, has pure brookite-phase. The rutile phase is increasing with increasing heat treatment temperature. The surface area and brookite phase are decreasing with increasing heat treatment temperature. The photocatalytic efficiency of the prepared brookite-TiO2 was evaluated by UV/Vis spectrophotometer to determine the concentration of methylene blue (MB). By the pseudo-first-order kinetic expression, the rates of photocatalytic degradation are affected by the photocatalyst heat treatment temperature, loading dosage, ratio of mixing phase, initial concentration of MB and the availability of ultrasound. The photocatalytic activity of anatase/brookite composite by physical method is better than single phase, i.e., anatase or brookite phase. The hydrolysis-TiO2 is about 70%anatase: 30%brookite composite by chemical method. The physical method of 50%brookite: 50%anatase in this study has the same photocatalytic efficiency in composion with the chemical method.