Dissertations / Theses: 'Textile chemistry. Dyes and dyeing'

1

Gilmore, Laurie Ann. "Chlorination of synthetic dyes and synthetic brighteners." Thesis, Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/20794.

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Seckin, M. Levent. "Effect of superba heatsetting on dyeing behavior of nylon 6,6 carpet yarns." Thesis, Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/8268.

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Li, Shiqi. "On-line dye analysis for carpet dyeing processes." Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/8596.

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Berry, Lee J. "Evaluation of novel plasticizers as carriers in dyeing aramid fabrics." Thesis, Georgia Institute of Technology, 1997. http://hdl.handle.net/1853/9978.

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5

Von, Hoven Terri Michelle. "Comparison of image analysis systems for their ability to detect the white speck phenomenon." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/8691.

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Mmelesi, Olga Kelebogile. "Synthesis and characterization of pine cone carbon supported iron oxide catalyst for dye and phenol degradation." Thesis, Vaal University of Technology, 2017. http://hdl.handle.net/10352/418.

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M. Tech. (Department of Chemical Engineering, Faculty of Engineering and Technology), Vaal University of Technology
Fenton oxidation is classified into two processes, homogeneous and heterogeneous. Homogeneous Fenton oxidation process, have been shown to be efficient in the degradation of organic pollutants. However, it was shown to have limitations which can be addressed by the heterogeneous Fenton oxidation. Despite the high efficiency of the heterogeneous Fenton oxidation process in the degradation of recalcitrant organic pollutants, the currents synthesis trends of the heterogeneous Fenton catalyst have been proven to be time and energy constraining, since it involves the multi-step were the activated carbon have to be prepared first then co-precipitate the iron oxide on the activated carbon. However, as much as the heterogeneous Fenton catalyst has been proven to have high catalytic activity towards degradation of organic pollutants, these catalysts have some limitations, such limitations include metal ions being leached from the catalyst support into the treated water causing catalyst deactivation and a secondary pollution to the treated water. In this thesis, these catalysts have been applied in the degradation of recalcitrant organic pollutants such as methylene blue and phenols. This study focuses on the single step synthesis of iron oxide nanoparticles supported on activated carbon, were carbonaceous material is impregnated with iron salt then pyrolysed via microwave heating. Microwave power and the amount of iron salt were optimized. The prepared activated carbon-iron oxide composites were applied to the degradation of 2-nitrophenol (2-NP) and methylene blue (MB). Methylene blue was used as a model compound due to the fact that it is easier to monitor the degradation process with UV-Vis as compared to 2-nitrophenol . 2-nitrophenol the additional step for the adjustment of pH is required since nitrophenols are colorless in color at lower pH. The characterization showed that the microwave power and the amount of the iron precursor have an influence on the porosity and surface functional groups of the activated carbon. Further it was vi observed that microwave power and iron precursor influnces the amount of iron oxide formed on the surface of the support. It was also observed that the activated carbon-iron oxide composite have the catalytic effects on the Fenton oxidation process of MB and 2-NP. The parameters such as H2O2, pH, catalyst dose, initial concentration, temperature affect the degradation of both MB and 2-NP. Kinetics studies showed that Fenton is a surface driven reaction since the results fitted the pseudo first order model. The thermodynamics parameters also showed that the reaction is endothermic, spontaneous and is randomized. This implies that the reaction of the degradation of MB and 2-NP is feasible and the catalysts prepared have high catalytic activity. MB and 2-NP were degraded to smaller organic molecules (carboxylic acids). The stability of the catalyst observed to decrease as the number of cycles increased, this is due to the leaching of iron ions from the support material. Hence it was concluded that the activated carbon-iron oxide composite was successfully synthesized and had the high catalytic activity for the degradation of MB and 2-NP.

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Boonroeng, Supannee. "An analysis system for dye delivery on continuous dyeing ranges." Thesis, Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/10175.

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Corner, David. "Reactive dyebath reuse systems." Thesis, Georgia Institute of Technology, 1999. http://hdl.handle.net/1853/8498.

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9

McFarland, Elizabeth Gramling. "A new method for determining diffusion and convection mass transfer coefficients in the dyeing of textile materials." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/12416.

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10

Alvares, A. Brenda C. "Ozone pretreatment to improve the biodegradation of recalcitrant textile azo dyes during wastewater treatment." Thesis, Cranfield University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391572.

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11

Gupta, Murari Lal. "Development of commercial, sustainable processes for dyeing generic, unmodified polypropylene fiber." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/26643.

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Thesis (Ph.D)--Polymer, Textile and Fiber Engineering, Georgia Institute of Technology, 2009.
Committee Chair: Cook, Fred; Committee Member: Beckham, Haskell; Committee Member: Bottomley, Lawrence; Committee Member: Carr, Wallace; Committee Member: Etters, Nolan. Part of the SMARTech Electronic Thesis and Dissertation Collection.

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12

Gonul, Mahmut. "Correlation of plasticizer chemical/physical properties to dyeability and finished characteristics of Nomex Aramid fabrics." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/8527.

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13

Thompson, Kimberlee Fay. "The role of singlet oxygen in the bleaching of cotton." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/8680.

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Matthews, Rosalyn D. "Transformation and decolorization of reactive phthalocyanine." Diss., Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04062004-164728/unrestricted/matthews%5Frosalyn%5Fd%5F200312%5Fphd.pdf.

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Thesis (Ph. D.)--School of Civil and Environmental Engineering, Georgia Institute of Technology, 2004. Directed by Spyros G. Pavlostathis.
Vita. Includes bibliographical references (leaves 381-393).

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15

Goetz, Charity. "Textile dyes techniques and their effects on the environment with a recommendation for dyers concerning the Green effect /." Lynchburg, Va. : Liberty University, 2008. http://digitalcommons.liberty.edu.

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16

Dayla, Mackraj. "Environmentally friendly dyeing and finishing." Thesis, Nelson Mandela Metropolitan University, 2013. http://hdl.handle.net/10948/d1020776.

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The textile industry in South Africa is a significant contributor to the chemical load that public wastewater treatment plants have to process, and the discharge of toxic substances, especially to the aquatic environment. In order to address this issue at factory level, the processes at a textile plant, JMV Textiles were chosen for investigation into the possibilities of minimization of discharges of harmful substances into the environment. The study followed the principles of cleaner production, and the processes that were investigated and revised were: The conventional peroxide bleaching process employed a peroxide stabilizer that did not biodegrade easily. The bleaching process was changed, so that the prevailing conditions in the fabric and dyebath facilitated bleaching without the addition of peroxide stabilizer, and also reduced the alkali and energy requirements. Polyester‐viscose fabric was pretreated by bleaching with hydrogen peroxide, which seemed to be unnecessarily rigorous, because polyester and viscose, unlike natural fibres, are relatively clean and have good whiteness in comparison with natural fibres. The proposed alternate pretreatment was a scour with detergent and alkali. The pretreatment for all polyester‐cotton fabrics was also a hydrogen peroxide bleach. Due to the ability of medium and dark shades to mask the natural tint of cotton fibres, a simpler alternate pretreatment, consisting of an alkaline scour with sequestering agent, was trialled. An unacceptable proportion of the dyeings on polyester was rejected for dye‐stains and dye‐marks. A possible solution exploited the properties of using the finishing auxiliary chemical to alleviate dye‐stains and dye‐marks during the dyeing stage, instead of using the chemical after dyeing. The highly toxic carrier that was used to facilitate level dyeing of polyester fibres that had unacceptable variation in their dyeing properties, was replaced by a less toxic carrier. The formulation for dyeing polyester was simplified to eliminate the auxiliary chemicals that were not essential to the dyeing process. Pale reactive dyed shades on cellulose and polyester‐cellulose were washed off only with hot water instead of detergent. The revised procedures consequential to the study, offered significant environmental benefits by reducing the concentration and volume of effluent produced, substituting a highly toxic carrier with a less toxic one and saving energy and water. Implementation of the suggested changes also offered financial benefits. The management of the factory, however, accepted and implemented some changes, but wanted further investigations for others and a phased approach to the other suggested changes.

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17

Horton, Aaron Michael. "Novel Reactive Dyes Based on Pyrimidine and Quinoxaline Systems." NCSU, 2009. http://www.lib.ncsu.edu/theses/available/etd-04302009-143537/.

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18

Beydilli, Mumtaz Inan. "Reductive biotransformation and decolorization of reactive azo dyes." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/21451.

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19

Li, Xiaofei. "New colorants for ink jet printing on textiles." Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/10113.

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20

Mousa, Souad Abd. "Photochemistry of β-carbolines and azine dyes in solution and colloidal systems." Thesis, Swansea University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.678433.

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21

Hubbell, Christopher. "Surface modification and chromophore attachment via ionic assembly and covalent fixation." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/28161.

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Thesis (M. S.)--Polymer, Textile and Fiber Engineering, Georgia Institute of Technology, 2009.
Committee Co-Chair: Beckham, Haskell; Committee Co-Chair: Cook, Fred; Committee Member: Collard, David; Committee Member: France, Stefan; Committee Member: Griffin, Anselm

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22

McCurdy, Michael W. "Chemical reduction and oxidation combined with biodegradation for the treatment of a textile dye wastewater." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-10102009-020050/.

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23

Lee, Young H. "Reductive biotransformation and decolorization of reactive anthraquinone dyes." Diss., Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-04062004-164708/unrestricted/lee%5Fyoung%5Fh%5F200312%5Fphd.pdf.

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Thesis (Ph. D.)--School of Electrical and Computer Engineering, Georgia Institute of Technology, 2004. Directed by Spyros G. Pavlostathis.
Vita. Includes bibliographical references (leaves 332-345).

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24

Loyd, Chapman Kemper. "Anaerobic/aerobic degradation of a textile dye wastewater." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-08042009-040351/.

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25

Ansell, Seth. "A study of ellipsoidal variance as a function of mean CIELAB values in a textile data set /." Online version of thesis, 1995. http://hdl.handle.net/1850/12232.

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26

Xue, Li. "Process Optimization of Dryers/Tenters in the Textile Industry." Thesis, Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5066.

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Textile dyeing and finishing industry uses dryers/tenters for drying and heat-setting fabrics. A very large fraction of the heating value of the fuel consumed in the burner ends up as waste in the dryer exhaust. An initial calculation showed that up to 90% of the energy consumed in the tenter is wasted. Therefore, quantifying the energy waste and determining drying characteristics are vitally important to optimizing the tenter and dryer operations. This research developed a portable off-line gas chromatography-based characterization system to assess the excess energy consumption. For low-demanding heat-setting situations, energy savings can be realized quickly. On the other hand, there are demanding situations where fabric drying represents the production bottleneck. The drying rate may be governed either by the rate of heat transport or by the rate of moisture transport. A mathematical model is being developed that incorporates both these processes. The model parameters are being obtained from bench-scale dryer studies in the laboratories. The model will be validated using production scale data. This will enable one to predict optimization dryer operation strategies.

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27

Lane, Karen Molly. "Analysis of knitted fabric models using image processing." Thesis, Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/8581.

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28

Schiller, Robert Lindsay. "Kinetic and equilibrium studies of some dye-cyclodextrin inclusion complexes /." Title page, contents and abstract only, 1986. http://web4.library.adelaide.edu.au/theses/09PH/09phs334.pdf.

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29

Park, Jong Seung. "Studies on inclusion complexes of cyclodextrin and dyes I. Synthesis and properties of dye rotaxanes, II. Formation of anisotropic supremolecules /." Available online, Georgia Institute of Technology, 2005, 2005. http://etd.gatech.edu/theses/available/etd-08262005-092849/.

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Thesis (Ph. D.)--Textile and Fiber Engineering, Georgia Institute of Technology, 2006.
Srinivasarao, Mohan, Committee Chair ; Bunz, Uwe, Committee Co-Chair ; Griffin, Anselm, Committee Member ; Tolbert, Laren, Committee Member ; Park, Jung, Committee Member ; Beckham, Haskell, Committee Member. Includes bibliographical references.

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30

Trujillo, Rebollo Andres. "ROLE OF BRILLIANT GREEN ON THE DETECTION AND SEPARATION OF NON-CHROMOPHORIC ANALYTES BY REVERSED-PHASE LIQUID CHROMATOGRAPHY (DIMERIZATION)." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275434.

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31

West, Lee Charles. "A study of bibracchial lariat ether complexes and linked cyclodextrin dimer complexes." Title page, contents and abstract only, 2000. http://web4.library.adelaide.edu.au/theses/09PH/09phw5182.pdf.

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Includes errata attached to first leaf. Includes bibliographical references. The complexation of a range of monovalent and divalent metal ions by the bibracchial lariat ethers has been investigated. Also investigates the complexation of metal ions and the anionic azo dye Brilliant Yellow by the diazacrown linked cyclodextrin dimers.

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32

Mutambanengwe, Cecil Clifford Zvandada. "Hydrogenases from sulphate reducing bacteria and their role in the bioremediation of textile effluent." Thesis, Rhodes University, 2007. http://hdl.handle.net/10962/d1004019.

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The continuing industrial development has led to a corresponding increase in the amount of waste water generation leading to a consequential decline in levels and quality of the natural water in the ecosystem. Textile industries consume over 7 x 10[superscript 5] tons of dyes annually and use up to 1 litre of water per kg of dye processed and are third largest polluters in the world, the problem being aggravated by the inefficiencies of the dye houses. An abundance of physio-chemical methods are in use world wide, however, there is increasing concern as to their impact in effectively treating textile effluents as they introduce secondary pollutants during the ‘remediation’ process which are quite costly to run, maintain and clean up. Research on biological treatment has offered simple and cost effective ways of bioremediating textile effluents. While aerobic treatment of textile dyes and their effluents has been reported, its major draw back is commercial up-scaling and as such anaerobic systems have been investigated and shown to degrade azo dyes, which form the bulk of the dyes used world wide. However, the mechanisms involved in the bioremediation of these dyes are poorly understood. The aims of this study were to identify and investigate the role of enzymes produced by sulphate reducing bacteria (SRB) in bioremediating textile dye and their effluents. Sulphate reducing bacteria were used in this study because they are tolerant to harsh environmental conditions and inhibit the proliferance of pathogenic micro-organisms. The appearance of clear zones in agar plates containing azo dye concentrations ranging from 10 – 100 mgl[superscript -1] showed the ability of SRB to decolourize dyes under anaerobic conditions. Assays of enzymes previously reported to decolourise azo dyes were not successful, but led to the identification of hydrogenase enzyme being produced by SRB. The enzyme was found to be localised in the membrane and cytoplasm. A surface response method was used to optimize the extraction of the enzyme from the bacterial cells resulting in approximately 3 fold increase in hydrogenase activity. Maximum hydrogenase activity was found to occur after six days in the absence of dyes but was found to occur after one day in the presence of azo dyes. A decline in hydrogenase activity thereafter, suggested inhibition of enzymatic activity by the putative aromatic amines produced after azo cleavage. Purification of the hydrogenase by freeze drying, poly ethylene glycol, and Sephacryl – 200 size exclusion- ion exchange chromatography revealed the enzyme to have a molecular weight of 38.5 kDa when analyzed by a 12 % SDS-PAGE. Characterisation of the enzyme revealed optimal activity at a pH of 7.5 and temperature of 40 °C while it exhibited a poor thermal stability with a half-life of 32 minutes. The kinetic parameters V[subscript max] and K[subscript m] were 21.18 U ml[superscript -1} and 4.57 mM respectively. Application of the cell free extract on commercial dyes was not successful, and only whole SRB cells resulted in decolourisation of the dyes. Consequently trials on the industrial dyes and effluents were carried out with whole cells. Decolourisation rates of up to 96 % were achieved for the commercial dyes and up to 93 % for the industrial dyes over a period of 10 days.

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33

Rushing, Charles W. Rushing Charles W. "Part A, Indoaniline dye formation ; Part B, Chlorite redox chemistry /." free to MU campus, to others for purchase, 2000. http://wwwlib.umi.com/cr/mo/fullcit?p9999311.

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34

Yang, Hanbae. "Zero-Valent Iron Decolorization of the Anthraquinone Dye Reactive Blue 4 and Biodegradation Assessment of its Decolorization Products." Thesis, Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6920.

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Anthraquinone dyes constitute the second largest class of textile dyes, and are used extensively in the textile industry. A high fraction of the initial reactive dye mass used in the dyeing process remains in the spent dyebath. Reactive dyes are not readily removed by typical wastewater treatment processes and the high salt concentration typical of reactive dyeing further complicates the management of spent reactive dyebaths. Investigation of the reductive transformation of reactive anthraquinone dyes and their decolorization products has been very limited. Additionally, very limited research has been conducted on the decolorization of spent reactive dyebaths. Research was conducted to investigate the key operational parameters of batch and continuous-flow ZVI decolorization of a reactive anthraquinone dye, Reactive Blue 4 (RB4), under anoxic conditions, as well as the potential for the biodegradation of its decolorization products in a halophilic culture under aerobic conditions. The effect of two operational parameters, such as mixing intensity and initial dye concentration, on the ZVI batch decolorization kinetics indicates that ZVI decolorization of RB4 is a surface-catalyzed, mass transfer-limited process. The high salt and base concentrations enhanced the rate of RB4 decolorization. Based on parameters such as porosity, hydraulic conductivity, pore water velocity, and dispersion coefficient, non-ideal transport characteristics were observed in a continuous-flow ZVI column. The results of a long-term continuous-flow ZVI decolorization kinetics demonstrated that continuous-flow ZVI decolorization is feasible. However, column porosity losses and a shift of reaction kinetics occur in long-term column operation. ZVI decolorization of RB4 was successfully described with a pseudo first-order or a site saturation model. Lastly, the RB4 decolorization products generated by ZVI treatment had no inhibitory effect on the halophilic culture. However, biodegradation and/or mineralization of RB4 decolorization products was not observed after a long-term incubation of the culture. This research demonstrated the feasibility of ZVI decolorization of reactive anthraquinone dyes, which will help in the development of a continuous-flow, dyebath decolorization process and the possible reuse of the renovated dyebath in the dyeing operation. Such a system could lead to substantial reduction of water usage, as well as a decrease of salt and dye discharges.

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35

Powell, William W. "The removal of color and DOC from segregated dye waste streams using ozone and Fenton's reagent followed by biotreatment." Thesis, Virginia Polytechnic Institute and State University, 1992. http://hdl.handle.net/10919/50105.

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The decolorization of reactive dye-containing waste streams using oxidizing chemicals and the determination of the effect of the oxidizing agents on the subsequent biotreatment of the streams was investigated. Three oxidizing schemes were chosen for study: molecular ozone, base-promoted ozonation, and Fenton’s reagent (Fe²⁺ and H₂O₂). The ADMI color value of the solutions was used as the primary parameter for color comparison and dissolved organic carbon (DOC) removal was the measure of the effect of biodegradation. Three different waste streams from a textile dyeing facility were chosen: a Navy slack washer effluent from a pad-dyeing operation, a Navy dyebath effluent from a dyejet, and a Brilliant Blue dyejet effluent. Pure dye solutions were oxidized as well to determine the effect of interfering species in the waste streams. The results demonstrated that base-promoted ozonation was more effective than molecular ozone for the decolorization of the Navy slack washer effluent. In both cases the ADMI color value could be decreased by 82% but almost half as much ozone was necessary for the high pH trials. The high pH ozonation proved more effective for the Navy jet-dye effluent, as well, achieving a much lower color value with less ozone. Greater decolorization (96%) of the Navy jet-dye effluent was achieved by Fenton’s reagent than for either of the ozonation schemes. Ozonation of the Brilliant Blue jet-dye bath showed no dependence on pH and the color value of the solution was reduced could be 63%. The results indicate that the dyes were selectively oxidized by ozonation and the amount of ozone required for decolorization depended mainly the initial color of the dye waste stream. The amount of hydrogen peroxide required for Fenton’s reagent oxidation depended on the initial DOC of the dye waste stream. Oxidation of the wastewater streams proved to neither enhance nor hinder the operation of the biological reactors. The color removals by biological activity were minimal for both control and experimental reactors. Dissolved carbon removal was not enhanced by oxidative pretreatment.
Master of Science
incomplete_metadata

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36

Giordano, João Batista. "Tratamento corona sobre superficies texteis." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266145.

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Orientador: João Sinezio de Carvalho Campos
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
Made available in DSpace on 2018-08-10T13:40:00Z (GMT). No. of bitstreams: 1 Giordano_JoaoBatista_D.pdf: 4390680 bytes, checksum: 205aa7153da8e4745f9366e58adcb8cf (MD5) Previous issue date: 2007
Resumo: Dentre as técnicas de modificação de superfícies aplicadas na indústria para melhorar adesão, o tratamento por descarga corona é amplamente utilizado. Durante o tratamento por descarga coro na, espécies ativas são geradas, as quais podem reagir com a superfície do polímero ocasionando quebra de cadeias e formação de radicais, criando assim grupos polares na superfície e conseqüentemente, aumentando a sua energia superficial e propriedade de adesão. Neste trabalho utilizaram-se tecidos de poliéster e de algodão. Nos processos convencionais de preparação de tecidos são usados agentes químicos que agridem os efluentes têxteis, assim a descarga corona propõe-se como tratamento prévio do material sem ação de tais agentes, sendo tratamento único e apenas físico. Os objetivos deste trabalho são: 1. Tratar com descarga corona tecidos de poliéster e tecidos de algodão (engomado, lavado e desengomado); 2. Verificar hidrofilidade e absorção de corantes em tecidos de algodão tratados com descarga corona; 3. Verificar propriedades mecânicas em tecidos tratados com descarga corona. 4. Verificar a adesão de pigmentos em de tecidos de poliéster tratados com corona. Tecidos foram submetidos à descarga: corona variando-se o tempo exposição e altura entre os eletrodos, em seguida foi realizada testes de hídrofilidade, absorção de corante tipo reativo, adesão de pigmentos, solidez a lavagem e ensaios de resistência à tração e alongamento. Foi utilizada a técnica de microscopia óptica, ensaio de hidrofilidade para caracterizar os efeitos causados. Os resultados mostram que: houve aumento da hidrofilidade do tecido de algodão que de 50% em amostra sem tratamento passou até a 280% com o tratamento, observou-se também que com te~pos de 1 mino já ocorrem modificações nos tecidos quanto a hidrofilidade e absorção de corantes; houve aumento da absorção de corante nas regiões tratadas principalmente em processos contínuos de tingimento; ocorreu boa aderência de pigmentos em tecidos de poliéster tratados; não ocorrem alteração das propriedades mecânicas (resistência a tração e alongamento) nas amostras tratadas.
Abstract: Amongst the techniques of modification of surfaces applied in the industry to improve adhesion, the treatment for discharge corona widely is used. During the treatment for discharge corona, active species are generated, which can consequently react with the surface of polymer causing chain in addition and formation of radicals, thus creating polar groups in the surface and, increasing its superficial energy and property of adhesion. In this work they had been used weaveed of polyester and cotton. In the conventional processes of fabric preparation they are used chemical agents whom the effluent textile attack, thus the discharge corona is considered as previous treatment of the material without action of such agents, being treatment only e only physicist. The objectives of this work are: 1.To deal with discharge corona weaveed to polyester and fabrics cotton (starchy, washed and dissolved the gum); 2. To verify water absorption and absorption of corantes in fabrics of cotton treated with discharge corona; to 3.Verificar mechanical properties in fabrics dealt with discharge corona. 4. To verify the pigment adhesion in of treated polyester fabrics with corona. Fabrics had been submitted to the discharge corona varying the time exposition and height between the electrodes and, after that water absorption tests had been carried through, absorption of corante reactive type, pigment adhesion, solidity the laudering and assays of tensile strenght and allonge. The technique of optic microscopy was used, assay of water absorption to characterize the caused effect. The results show that: it had increase of the hidrofilidade of the cotton fabric that of 50% in sample without treatment passed until 280% with the treatment, was 9.lso observed that with times of 1 min. already the water absorption and absorption of corantes occur modifications in fabrics how much; it had increase of the absorption of corante in the regions treated mainly in continuous processes of dyeing good pigment tack occurred in treat polyester fabrics; they do not occur alteration of the mechanical properties (resistance the traction and allonge) in the treated samples.
Doutorado
Ciencia e Tecnologia de Materiais
Doutor em Engenharia Química

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37

Mothibedi, Kediemetse (Kedimetse). "A study of electrospun nanofibers and diatomaceous earth materials for the extraction of alkaloids, flavonoids and aromatic amines in various matrices." Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1003052.

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The thesis explored the use of different sorbent materials in solid phase extraction method development. The methods included the use of the polymeric Agilent Bond Elut Plexa solid phase extraction and electrospun polymer-silica composite sorbents for clean-up and preconcentration. Sample clean-up for alkaloids (hydrastine and berberine) in goldenseal, Hydrastis canadensis and flavonoids (quercetin, kaempferol and isorhamnetin) in Ginkgo biloba was achieved using Bond Elut Plexa SPE sorbent. Clean-up of flavonoids in Ginkgo biloba was also achieved using electrospun polymer-silica composite (polystyrene-silica, polyacrylonitrile-silica and nylon 6-silica) sorbents. All analysis of flavonoids and alkaloids was carried out using an Agilent 1200 Series HPLC coupled with a diode array detector. Good peak separation was achieved in less than 6 min employing an Agilent ZORBAX Eclipse Plus C18 column (4.6 x 75 mm, 3.5 μm) at 35⁰C. The mobile phases employed were 0.1% phosphoric acid/methanol gradient and 0.5% phosphoric acid/methanol (40:60) for alkaloids and flavonoids respectively. The calibration curves exhibited linearity up to 120 μg mL⁻¹ with correlation coefficients of more than 0.9980. The recoveries ranged from 73-109% with relative standard deviation of less than 5% for all analytes. Agilent Chem Elut supported liquid extraction was employed for the development of a sample preparation method for the determination of 24 banned aromatic amines from azo dyes in textile following the EU standard method EN 14362-1:2003 (E) and the Chinese standard method GB/T 17592-2006. The supported liquid extraction was effective in the extraction of the aromatic amines from textile (cotton, wool and polyester/cotton [80%:20%]). Most of the recoveries obtained were conforming to the minimum requirements set in the EN 14362-1:2003 (E) standard method and the relative standard deviations were less than 15%. Good peak separation was obtained within 70 min run time using the Agilent Zorbax SB-Phenyl column (4.6 mm x 250 mm, 5-micron) or the Agilent DB-35 MS (J & W) (30 m x 0.25 mm, 0.25 μm film thickness. It was demonstrated that the polymeric Agilent Bond Elut Plexa, electrospun nanofibers and diatomaceous earth were effective in extraction of alkaloids, flavonoids and aromatic amines in different matrices. The developed methods were simple, rapid and reproducible.

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Park, Jong Seung. "Studies on Inclusion Complexes of Cyclodextrin and Dyes; I.Synthesis and Properties of Dye Rotaxanes, II. Formation of Anisotropic Supremolecules." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7482.

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Supramolecular chemistry covers intermolecular interactions where non-covalent bonds are involved, and many of them are based on host-guest interactions. Cyclodextrins (CDs) are cyclic oligosaccharides consisting of 6-, 7- or 8-glucose units, which are called alpha-, beta- or gamma-CDs, respectively. They have hydrophobic interior and hydrophilic exterior, and are widely being used as hosts for various organic molecules. The formation of CD inclusion complexes with a variety of dyes has continuously drawn our interests, since CDs are readily available and have ability to include dye molecules altering their properties. The present thesis covers the study of inclusion complexes of CDs and chromophore dyes, largely in two ways; rotaxane and pseudorotaxane. The stable rotaxane structure is achieved with the synthesis of dye rotaxane. The introduction of CD ring around azo chromophore provides a simple way to improve the solubility and stability of azo dye. We have shown that by incorporating proper compounds as a coupler, azo dye rotaxanes can be used as pH indicators and metal ion sensors. We have described the synthesis of novel acetylene dye rotaxane using the Pd-catalyzed reaction of Heck-Cassar-Sonogashira-Hagihara type. Its fluorescence properties in the solid state as well as in solutions are examined and compared with those of free dye. Free dye, which has tetra-carboxylic groups, is found to be highly sensitive to various metal ions, exhibiting high Stern-Volmer constants, K(SV). On the contrary, acetylene dye rotaxane exhibits much less quenching against various quenchers. The appearance of fluorescent anisotropic structure has been observed by the formation of inclusion complex between acetylene dye and gamma-CD. Its structural nature is studied by various techniques, including fluorescence, fluorescence anisotropy, wide angle X-ray scattering (WAXD) and differential scanning calorimetry (DSC) measurements. Methyl orange, an acid azo dye, forms a dimeric inclusion complex with gamma-CD, resulting in the formation stable anisotropic aggregates. Several other azo dyes are found to form anisotropic supramolecule in the presence of gamma-CD, and their structural characteristic has been discussed in terms of the number and position of solubilizing groups.

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39

White, Katie Margaret. "Statistical analysis of visible absorption spectra and mass spectra obtained from dyed textile fibers." Master's thesis, University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4646.

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The National Academy of Sciences recently published a report which calls for improvements to the field of forensic science. Their report criticized many forensic disciplines for failure to establish rigorously-tested methods of comparison, and encouraged more research in these areas to establish limitations and assess error rates. This study applies chemometric and statistical methods to current and developing analytical techniques in fiber analysis. In addition to analysis of commercially available dyed textile fibers, two pairs of dyes are selected for custom fabric dyeing based on the similarities of their absorbance spectra and dye molecular structures. Visible absorption spectra for all fiber samples are collected using microspectrophotometry (MSP) and mass spectra are collected using electrospray ionization (ESI) mass spectrometry. Statistical calculations are performed using commercial software packages and software written in-house. Levels of Type I and Type II error are examined for fiber discrimination based on hypothesis testing of visible absorbance spectra profiles using a nonparametric permutation method. This work also explores evaluation of known and questioned fiber populations based on an assessment of statistical p-value distributions from questioned-known fiber comparisons with those of known fiber self-comparisons. Results from the hypothesis testing are compared with principal components analysis (PCA) and discriminant analysis (DA) of visible absorption spectra, as well as PCA and DA of ESI mass spectra. The sensitivity of a statistical approach will also be discussed in terms of how instrumental parameters and sampling methods may influence error rates.
ID: 030423335; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.)--University of Central Florida, 2010.; Includes bibliographical references (p. 112-119).
M.S.
Masters
Department of Chemistry
Sciences

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40

Sanyova, Jana. "Contribution à l'étude de la structure et des propriétés des laques de garance." Doctoral thesis, Universite Libre de Bruxelles, 2001. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/211674.

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Les laques de garance, les pigments artistiques dont les procédés de fabrication étaient souvent des secrets jalousement gardés, ont depuis longtemps éveillé l'intérêt des chimistes. Le premier mode opératoire de laque de garance décrit scientifiquement est dû à Marggrave en 1754, chimiste allemand célèbre surtout pour la découverte du sucre de betterave. L'élucidation de la structure chimique de l'alizarine par Graebe en 1868 est une des étapes fondatrices de la chimie organique. Il a ensuite vite été reconnu que, dans les laques, l'alizarine se trouve sous forme de complexes d'aluminium. Plusieurs structures ont été proposées dans la littérature pour les complexes d'alizarine et d'aluminium. Le site de complexation de l'aluminium y est constitué soit par les fonctions carbonyle en C-9 et phénolate en C-1 (site céto-phénolate), soit par les deux fonctions phénolates en C-1 et C-2 (site diphénolate).

Nos résultats montrent que, au moins en solution aqueuse diluée et acide, le site de complexation est le céto-phénolate et la stoechiométrie 1:1. En solution plus concentrée et neutre ou légèrement basique, il peut également se former des complexes de stoechiométrie 1:2, dont la couleur est par ailleurs pratiquement identique à celle des complexes de stoechiométrie 1:1. Quand les réactifs sont mis en présence en rapport stoechiométrique et neutralisés par NaOH (aluminium:alizarine:NaOH 1:2:5), les complexes 1:2 ainsi formés peuvent même polymériser en formant entre eux des liaisons Al-O-Al. Cependant, dans la pratique de la préparation des laques, aujourd'hui comme dans le passé, l'aluminium est présent en large excès par rapport à l'alizarine. Dans ces conditions, les complexes, au lieu de polymériser, s'adsorbent à la surface des grains d'alumine formés par l'aluminium en excès. Nous n'avons trouvé aucune indication de la formation de complexes 2:4. Il est probable que de tels complexes ne sont, comme les gels que nous avons obtenus dans certaines conditions, que des cas particuliers, non représentatifs de la structure des laques réelles. La stoechiométrie des complexes et leur état physique ne seraient que des caractéristiques secondaires. Dans le cas des laques utilisées comme pigments, il s'agirait de complexes 1:2 et probablement aussi 1:1, adsorbés sur les grains d'alumine via des liaisons Al-O-Al.

La compétition entre ions H+ et Al3+ pour les phénolates est à la base de la libération des molécules d'alizarine dans les méthodes classiques d'extraction des colorants des laques par un acide pour leur analyse par HPLC. Nos résultats montrent que la concentration en ions H+ nécessaire pour libérer les colorants est proportionnelle à la concentration en ions Al3+ en solution. Dans la pratique, le pH nécessaire est très bas, ce qui a pour conséquence négative d'hydrolyser certaines des molécules colorantes constitutives des laques. L'addition d'ions F- permet de pallier ce problème. En formant des complexes avec les ions Al3+, les ions F- relèvent assez le pH minimum d'extraction pour éviter l'hydrolyse des colorants moins stables (glycosides, pseudopurpurine.), et donnent de plus des rendements d'extraction souvent meilleurs que ceux obtenus avec les autres acides (HCl, H2SO4, TFA). L'addition d'ions Li+, qui par leur petite taille peuvent plus facilement se glisser à l'intérieur des complexes, et d'agents chélatants tels que le DFOM, qui contribuent à capter les ions Al3+, améliore encore l'extraction des colorants.

Des propriétés telles la granulométrie, la porosité et l'hygroscopicité des laques sont celles de l'alumine qui constitue leur substrat. Les analyses de différentes laques d'extraits de Rubiacées montrent :

- la présence fréquente de pseudopurpurine et de glycosides; ces colorants ne sont détectés qu'après extraction à pH ~ 2 (extraction par HF), parce qu'à pH plus acide ils sont hydrolysés.

- la teneur en différents colorants est influencée non seulement par l'espèce de plante, mais aussi par le mode de préparation des laques.

La couleur apparente et les spectres dans le visible des chélates aluminium-anthraquinone sont bien distincts de ceux des mêmes colorants en l'absence d'aluminium. Les paramètres L*a*b* et leur équivalent en coordonnées cylindriques L*c*h*, calculés à partir des spectres de réflectance, permettent de caractériser la couleur des objets, telle qu'elle serait perçue sous une lumière de spectre donné et par un "observateur de référence". On constate que la teinte des laques dépend surtout de la nature des colorants présents sous forme de chélates d'aluminium. La saturation dépend surtout du rapport aluminium/colorant, et augmente avec celui-ci, ce qu'on peut attribuer à un meilleur rendement de la formation de complexes quand l'aluminium est présent en plus large excès.

Pour mieux comprendre les facteurs affectant la permanence des laques, une approche est de soumettre des laques préparées dans des conditions connues à des tests de vieillissement accéléré par une lampe à arc de xénon. Une première étude de ce type menée sur des laques sous forme de poudres fixées sur des filtres montre que dans les laques fort concentrées au départ, la majorité des colorants peut être dégradée sans que la couleur perceptible ait fort changé. A l'observation au microscope, on constate que les grains les plus petits ont tendance à décolorer plus vite. Cependant globalement le principal facteur affectant l'évolution de la couleur est la concentration en colorants. Il semble donc que les complexes de colorants adsorbés à la surface de la porosité interne des grains d'alumine soient protégés de la lumière par les complexes adsorbés dans les couches plus externes, et que cette protection soit proportionnelle à la concentration en colorant. La photodégradation est probablement oxydative. Elle est d'ailleurs beaucoup plus lente pour les teintures d'alizarine sur laine, grâce probablement aux propriétés réductrices de la laine. Il faut donc s'attendre à ce que, dans les polychromies, la présence des liants ralentisse le vieillissement en limitant la diffusion de l'oxygène, ce qui n'était pas le cas dans nos laques poreuses vieillies au contact de l'air. C'est là un des aspects que la suite des études de vieillissement accéléré devrait tenter d'éclaircir.

Doctorat en sciences appliquées
info:eu-repo/semantics/nonPublished

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41

Sotiles, Anne Raquel. "Estudo de diferentes tratamentos da caulinita para possível aplicação como adsorvente do corante têxtil C.I. Reactive Blue 203." Universidade Tecnológica Federal do Paraná, 2017. http://repositorio.utfpr.edu.br/jspui/handle/1/2289.

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CAPES; Fundação Araucária
A caulinita é um argilomineral empregado em diversos setores industriais e, em decorrência da elevada disponibilidades na crosta terrestre são realizadas modificações químicas para a obtenção de diferentes estruturas do material buscando ampliar sua utilização. Foram realizadas ativações com ácidos fosfórico e sulfúrico nas concentrações de 5 e 10 mol L-1, e tratamentos térmicos em 850, 1100 e 1200 ºC visando a aplicação deste argilomineral na adsorção do corante têxtil Reactive Blue 203. As amostras foram caracterizadas por Difratometria de Raios X (DRX), Espectroscopia na Região do Infravermelho com Transformada de Fourier (FTIR), Análise Termogravimétrica (TGA), Análise Térmica Diferencial (DTA) e Microscopia Eletrônica de Varredura (MEV). Nos espectros de FTIR das amostras calcinadas houve o desaparecimento das absorções características da hidroxila, além do surgimento de vibrações atribuídas a metacaulinita, que é formada a partir da calcinação da caulinita. Pelo DRX foi possível confirmar as alterações da estrutura, pois o difratograma apresentou característica de material amorfo quando calcinado em 850 °C, enquanto que nas temperaturas de 1100 e 1200 °C o material voltou a apresentar estrutura cristalina, devido a formação da mulita. Essas modificações também são evidentes na análise térmica, sendo que o evento ocorrido na curva termogravimétrica entre 420 ºC e 700 ºC refere-se à desidroxilação do material e consequentemente, à formação da metacaulinita. Já a análise térmica diferencial apresentou um pico exotérmico na região de 1000 ºC, correspondendo à conversão da metacaulinita em mulita. Entretanto, a análise de MEV não demonstrou mudanças na morfologia do material. O ponto de carga zero obtido para a caulinita foi de 4,41, correspondendo ao valor de pH em que a carga superficial é zero, sendo que em valores de pH superiores a este a caulinita estará mais propícia a adsorver substâncias catiônicas e em valores de pH inferiores, aniônicas. A caulinita apresentou maior quantidade de sítios ácidos, uma vez que ambas as análises resultaram em valores de pH inferiores a 7, característicos de argilominerais com estrutura lamelar, devido a presença das hidroxilas internas e do alumínio, uma vez que trata-se de um aluminossilicato. No teste de adsorção com o corante têxtil Reactive Blue 203 a caulinita sem tratamento se sobressaiu perante as demais amostras, com melhor ajuste da isoterma de Sips e cinética de pseudo-segunda ordem. Os parâmetros termodinâmicos indicam que se trata de um processo espontâneo e endotérmico e evidenciam que ocorre uma adsorção química.
The kaolinite is a clay mineral used in several industrial sectors and, due to the high availability in the earth's crust, chemical modifications are made to obtain different structures of the material in order to expand its use. Activations were carried out with phosphoric and sulfuric acids at concentrations of 5 and 10 mol L-1, and thermal treatments at 850, 1100 and 1200ºC for the application of this clay in the adsorption of Reactive Blue 203 textile dye. The samples were characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Differential Thermal Analysis (DTA) and Scanning Electron Microscopy (SEM). In the FTIR spectra of the calcined samples, the characteristic hydroxyl absorptions disappeared, as well as the appearance of vibrations attributed to metacaulinite, which is formed from calcination of kaolinite. By XRD, it was possible to confirm the changes in the structure, since the diffractogram showed a characteristic of amorphous material when calcined at 850 °C, while in the temperatures of 1100 and 1200 °C the material returned to present crystalline structure, due to the formation of the mullite. These changes are also evident in the thermal analysis, and the event occurring in the thermogravimetric curve between 420 ºC and 700 ºC refers to the dehydroxylation of the material and, consequently, to the formation of metakaolin. The differential thermal analysis showed an exothermic peak in the region of 1000 ºC, corresponding to the conversion of metacaulinite to mullite. However, SEM analysis did not show changes in material morphology. The zero charge point obtained for kaolinite was 4.41, corresponding to the pH value at which the surface charge is zero, and at pH values higher than that kaolinite will be more propitious to adsorb cationic substances and in values of pH lower, anionic. The kaolinite presented higher amount of acidic sites, since both analyzes resulted in pH values lower than 7, characteristic of clay minerals with lamellar structure, due to the presence of internal hydroxyls and aluminum, since it is an aluminosilicate. In the adsorption test with the Reactive Blue 203 textile dye, the untreated kaolinite stood out in the other samples, with better adjustment of the Sips isotherm and pseudo second order kinetics. The thermodynamic parameters indicate that it is a spontaneous and endothermic process and evidence that a chemical adsorption occurs.

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42

Hansa, Ayesha. "The development of techniques for the analysis of reactive dyes in textile dyeing wastewater." Thesis, 1999. http://hdl.handle.net/10321/2860.

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Submitted in partial fulfilment of the requirements for the Degree of Masters of Technology: Chemical Engineering, M.L. Sultan Technikon, 1999.
An environmental problem facing the textile industry is the coloured effluent from the dyeing of cellulosic fibres with reactive dyes. Reactive dye loss during dyeing operations is about 10 to 40 %, indicating the need to learn more about the fate of these dyes. Increasing environmental regulations are driving technical innovation to manage this problem. Good analytical techniques for the separation and detection of reactive dyes and their derivatives are necessary for monitoring dye-house effluent, as well as in the optimisation of dye synthesis, purification, formulation and application.
M

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43

Reichard, Eric Jonathan. "Chemometrics applied to the discrimination of synthetic fibers by microspectrophotometry." 2014. http://hdl.handle.net/1805/3795.

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Indiana University-Purdue University Indianapolis (IUPUI)
Microspectrophotometry is a quick, accurate, and reproducible method to compare colored fibers for forensic purposes. The use of chemometric techniques applied to spectroscopic data can provide valuable discriminatory information especially when looking at a complex dataset. Differentiating a group of samples by employing chemometric analysis increases the evidential value of fiber comparisons by decreasing the probability of false association. The aims of this research were to (1) evaluate the chemometric procedure on a data set consisting of blue acrylic fibers and (2) accurately discriminate between yellow polyester fibers with the same dye composition but different dye loadings along with introducing a multivariate calibration approach to determine the dye concentration of fibers. In the first study, background subtracted and normalized visible spectra from eleven blue acrylic exemplars dyed with varying compositions of dyes were discriminated from one another using agglomerative hierarchical clustering (AHC), principal component analysis (PCA), and discriminant analysis (DA). AHC and PCA results agreed showing similar spectra clustering close to one another. DA analysis indicated a total classification accuracy of approximately 93% with only two of the eleven exemplars confused with one another. This was expected because two exemplars consisted of the same dye compositions. An external validation of the data set was performed and showed consistent results, which validated the model produced from the training set. In the second study, background subtracted and normalized visible spectra from ten yellow polyester exemplars dyed with different concentrations of the same dye ranging from 0.1-3.5% (w/w), were analyzed by the same techniques. Three classes of fibers with a classification accuracy of approximately 96% were found representing low, medium, and high dye loadings. Exemplars with similar dye loadings were able to be readily discriminated in some cases based on a classification accuracy of 90% or higher and a receiver operating characteristic area under the curve score of 0.9 or greater. Calibration curves based upon a proximity matrix of dye loadings between 0.1-0.75% (w/w) were developed that provided better accuracy and precision to that of a traditional approach.

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44

Dymond, Scarlett Miranda. "Social and physical factors influencing the use and consumption of European fabric by nineteenth century indigenous societies in the old Transvaal." Thesis, 2012. http://hdl.handle.net/10539/11438.

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M.Sc., Faculty of Science, University of the Witwatersrand, 2011
In 1854 friction over labour practices, land appropriation and inland trade routes led to the simultaneous murder of three groups of Dutch settlers, or Trekkers by the Kekana Ndebele. The Trekkers mounted a retaliatory attack on the Kekana, who retreated into Historic Cave, Limpopo Province. Although the cave had been well stocked prior to the attack, the Kekana were decimated and this event later became known as the Siege of Makapan. Excavations from 2001 uncovered a unique cache of European fabric preserved by the unusually dry conditions in the cave. Within the fluid social and political landscape of the internal frontier of nineteenth century northern Transvaal, European clothing and fabric was a valuable resource that served different functions. Contemporary records from traders, travellers and missionaries indicate that, as a high status item, clothing and fabric was often restricted to elites, was subject to social mores and could be used to signal changing religious or political affiliations. Certain groups, or individuals, also invested fabric with unusual properties. No entire garments were recovered from Historic Cave but some of the fragmentary fabric remains that were revealed indicate their possible use as ritual objects endowed with supernatural qualities. The unique find from Historic Cave allows an opportunity of comparing archaeological remains with historical documents to understand more about fabric use at this time.

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Nadupalli, Srinivasu. "Oxidative degradation of textile dyes with hypochlorite and chlorine dioxide." Thesis, 2010. http://hdl.handle.net/10413/5359.

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The oxidation reaction mechanisms of water soluble textile dyes amaranth (an azo dye), brilliant blue-R (a triaryl dye) and safranine-O (an azine dye) with oxidants- hypochlorite and chlorine dioxide, were investigated. The detailed kinetics of the reactions of the three dyes was studied under excess concentrations of the oxidant and other reagents. The depletion of concentration of the chosen dye, taken at low concentration was monitored using a Hi-Tech SF-61 DX2 double mixing micro volume stopped-flow apparatus. The hypochlorite initiated oxidations were investigated as function of varying concentration of oxidant and hydrogen ion, ionic strength and temperature. For the chosen dyes and reaction conditions, the depletion of dye followed pseudo first-order kinetics and the rate constants were estimated using KinetAsystTM software. All the three reactions had first-order dependence on the oxidant concentration, and the reaction rates increased by varied extent with increase in [H+]0. The role of acid in their reaction mechanisms was established. The kinetic data was analysed to evaluate the rate constants for the competitive pathways initiated by hypochlorite ion and hypochlorous acid. The overall second-order rate coefficients for the OCl- and HOCl initiated reactions were estimated for all the three reactions. Major oxidation products for the reactions were separated and characterized by 1H NMR and 13C NMR and GC-MS techniques and the stoichiometry was established. The energy parameters inclusive of Arrhenius factor, enthalpy, entropy and energy of activations for the oxidation of three dyes both by OCl- and HOCl species were estimated. Based on the experimental findings, the probable rate laws, mechanisms and reaction schemes were described. Simulations studies were conducted to validate the proposed mechanisms using SIMKINE2 computer programme. The rate of oxidation of safranine-O is greater than that of amaranth and brilliant blue-R with OCl- / HOCl reaction. Following similar protocol, the oxidations of the chosen dyes with chlorine dioxide were investigated by monitoring the depletion kinetics of dye as function of varying concentration of ClO2 and OH- ion, ionic strength and temperature. All the three dyes, exhibited pseudo first-order kinetics and the rate constants were estimated using KinetAsystTM software. All the three reactions had first-order dependence on the oxidant concentration at pH conditions 7.0, 8.0 and 9.0 suggesting that reaction mechanism remains unaltered with pH variation. The effect of hydroxide ion on the reaction rate revealed that it acts as catalyst. All the three reactions had first-order dependence on [OH-]0, when its concentration was low; but the order with respect to [OH-] decreased as [OH-] increased stoichiometry proportion to reactants. The catalytic constant for hydroxide catalysed reaction was estimated for all the three reactions. Kinetic salt effect experiments were conducted to identify the possible reaction species involved in the reactions. The major reaction products were characterized by 1H NMR, 13C NMR and GC-MS techniques. The stoichiometry ratios were established and energy parameters were estimated. The rate laws and probable reaction mechanisms were proposed and appropriate reaction schemes for all the reactions were described. The elucidated mechanisms were confirmed by simulation studies using SIMKINE2 software. At neutral pH the rate of oxidation of amaranth is greater than safranine-O and brilliant blue-R, and brilliant blue R being the slowest.
Thesis (Ph.D.)-University of KwaZulu-Natal, Westville, 2010.

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46

Mutambanengwe, Cecil Clifford Zvandada. "Hydrogenases from sulphate reducing bacteria and their role in the bioremediation of textile effluent /." 2006. http://eprints.ru.ac.za/869/.

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Ngulube, Tholiso. "Removal of cationic and anionic dyes from aqueous solution using a clay-based nanocomposite." Thesis, 2019. http://hdl.handle.net/11602/1415.

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PhDENV
Department of Ecology and Resource Management
Some industries such as textiles, ceramics, paper and printing are known to use significant amounts of dye to colour their products and during the colouring process, certain quantities of dyes are absorbed by the products, and some of them end up in wastewater. Depending on their application, some synthetic dyes are designed to be chemically or biologically resistant and their presence in the environment can cause severe environmental problems because of their colour impartation to water bodies. Therefore, proper treatment is required to remove these pollutants from wastewater before discharge into the environment. In this thesis, the potential of dye removal from wastewater by calcined magnesite, halloysite nanoclay and calcined magnesite - halloysite nanoclay composite was evaluated. To this end, the study was subdivided to four segments. The first segment of the study focused on evaluating the efficiency of using calcined magnesite to remove Methylene Blue (MB), Direct Red 81 (DR81), Methyl Orange (MO) and Crystal Violet (CV) dyes from aqueous systems using a batch study. To achieve that, several operational factors like residence time, adsorbent dosage, dye concentration and temperature were appraised. The adsorbent was subjected to different kinds of physicochemical characterization to determine the various characteristics that would assist in the dye uptake process. Characterization results showed that the adsorbent material was highly crystalline with magnesite, periclase, dolomite, and quartz as some of the crystalline phases. The batch study proved that calcined magnesite is effective in the treatment of dye contaminated water and moreover it performed well in terms of colour removal, though exceptional results were recorded for CV removal with complete decolourisation occurring in first few minutes of contact. In terms of experimental adsorption capacity, the performance of calcined magnesite was in the order CV (14.99 mg/g) > DR81 (12.56 mg/g) > MO (0.64 mg/g) > MB (0.39 mg/g). Mechanisms of adsorption where explained by fitting the experimental data into adsorption isotherms, kinetics, and thermodynamic parameters. Neither, the Langmuir, nor the Freundlich nor the Dubinin Radushkevich, nor the Temkin model could perfectly describe the adsorption of the four dyes onto calcined magnesite, however adsorption kinetics obeyed the pseudo second order model, implying that, the dye removal process was primarily a chemical process. In accordance with the results of this study, it can be concluded that calcined magnesite can be used effectively for the removal of dyes in aqueous solution and thus can be applied to treat wastewater containing dyes. The second segment of the study focused on the removal of MB, DR81, MO and CV dyes by halloysite nanoclay. Physicochemical characterisation revealed that the nanoclay has a surface area of 42 m²/g and its ABSTRACT iv morphology is predominated by tubular structures, which exhibit some hollow rod like structures. Various important parameters namely contact time, initial concentration of dyes, dosage, solution temperature and solution pH were optimized to achieve maximum adsorption capacity and it was observed that the effect of initial pH and temperature of the aqueous solution was neglibible on removal of the four dyes. The experimental adsorption capacities towards 40 mg/L of MB, DR81, MO and CV dyes were 17.51, 14.11, 0.38, and 4.75 mg/g respectively. The results indicate that natural halloysite nanoclay is an efficient material for the removal of the selected dyes. Due to its low cost and non-toxicity, halloysite nanoclay can be considered a good replacement option of other high cost materials used to treat coloured wastewater especially in developing countries like South Africa. Having observed the performance of calcined magnesite and halloysite nanoclay individually in the removal of selected dyes, a third study was designed with the aim of preparing a nanocomposite adsorbent from the aforementioned adsorbent materials and then evaluating the synergistic influence of the mechanochemical modification by a ball miller on the removal of MB, DR81, MO and CV dyes. Physicochemical characterization was carried out to get an insight of pre- and -post adsorption characteristics of the nanocomposite material and results showed major changes which could be an indication of dye uptake by the nanocomposite material. According to the results, the nanocomposite material outcompeted its component individual constituent materials i.e (calcined magnesite and halloysite nanoclay material) in the removal of DR81, which in turn was the highest removal efficiency observed for the whole batch adsorption study recording a maximum adsorption capacity and percentage removal of 19.89 mg/g and 99.40% respectively. Experimental results fitted the Langmuir and pseudo-second order models perfectly hence demonstrating that adsorption took place on a homogenous adsorbent layer via chemisorption. In overall, the results suggested that the nanocomposite is a suitable adsorbent for decolourising industrial wastewater. Based on the overall performance of the adsorbents in removing the four dyes, it was observed that the nanocomposite material had a high affinity for DR81 dye hence it was chosen as the model dye for further application in column studies. The effect of flow rate, bed height and initial dye concentration on the removal of DR81 was investigated. Maximum bed capacity and equilibrium dye uptake were determined and break through curves were plotted. Percentage dye removal increased with decrease in flow rate and increase in bed height. The maximum capacity of column was found to be about 51.73 mg DR81 per gram of the nanocomposite adsorbent for a flow rate of 3 mL/min, initial concentration of 10 mg/L and 4 cm bed height. Data from column studies was fitted to the Thomas model and Adams-Bohart models. The comparison of the R2 values obtained from both models showed a better fit for the nanocomposite material than the individual halloysite nanoclay and calcined magnesite materials. The study revealed the applicability of calcined magnesite- halloysite nanoclay composite in fixed bed column for the removal of DR81 dye from aqueous solution. v The reuse of an adsorbent is essential in order to make the adsorption process economic and environmentally friendly. To recover the adsorbate and renew the adsorbent for further use, a chemical method of regeneration was applied by using 0.1 M NaOH as the desorbent. Regeneration with 0.1 M NaOH proved very efficient for some dyes and less efficient for others depending on the adsorbent material used at the time. The general observation was that the adsorption capacity of the adsorbent materials decreased with successive adsorption – desorption cycles. Furthermore, regeneration with NaOH, favoured the acidic dyes (DR81 and MO) more than the basic dyes (MB and CV) possibly due to electrostatic interactions between oppositely charged molecules allowing for reversible reactions to take place. The three tested adsorbents namely calcined magnesite, halloysite nanoclay and their nanocomposite thereof were applied for the treatment of real wastewater effluent from a printing and ink industry. The adsorbents performed very well in terms of colour removal as recommended by the South African standards of wastewater discharge, However, in terms of pH, calcined magnesite and the nanocomposite produced a highly alkaline solution hence wastewater neutralisation by an acid is recommended before discharge. These findings show that the two natural clay-based materials (calcined magnesite and halloysite nanoclay) and their nanocomposite thereof have a great potential for application in dye wastewater remediation since the materials used in the process are inexpensive, abundant and require minimal modifications.
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48

"Development and characterisation of a propriety polymer matrix for enhanced optical properties." Thesis, 2014. http://hdl.handle.net/10210/8857.

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49

"Price reduction or "service package"?: a study of alternative marketing strategies." Chinese University of Hong Kong, 1989. http://library.cuhk.edu.hk/record=b5886020.

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50

"Toxicity identification evaluation of effluent from dyeing industry =: 染廠廢水的毒性鑒定評估研究." 2003. http://library.cuhk.edu.hk/record=b5896109.

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Abstract:

by Chung Ho Yan.
Thesis (M.Phil.)--Chinese University of Hong Kong, 2003.
Includes bibliographical references (leaves 127-141).
Text in English; abstracts in English and Chinese.
by Chung Ho Yan.
Acknowledgments --- p.i
Abstract --- p.ii
Table of Contents --- p.v
List of Figures --- p.xi
List of Plates --- p.xiv
List of Tables --- p.xv
Chapter 1. --- INTRODUCTION --- p.1
Chapter 1.1 --- Textile-Dyeing Industry in Hong Kong --- p.1
Chapter 1.2 --- Processes Involved in Dyeing Industry --- p.3
Chapter 1.2.1 --- Desizing --- p.3
Chapter 1.2.2 --- Scouring --- p.3
Chapter 1.2.3 --- Bleaching --- p.3
Chapter 1.2.4 --- Mercerizing --- p.4
Chapter 1.2.5 --- Dyeing and Printing --- p.4
Chapter 1.2.6 --- Finishing --- p.4
Chapter 1.3 --- Characterization of Wastewater of Dyeing Industry --- p.5
Chapter 1.4 --- Toxicity of Effluent from Textile-Dyeing Industry --- p.9
Chapter 1.5 --- Related Environmental Legislation --- p.9
Chapter 1.6 --- Chemical Specific Approach and Toxicity Based Approach --- p.11
Chapter 1.7 --- Whole-Effluent Toxicity (WET) Test --- p.13
Chapter 1.8 --- Toxicity Identification Evaluation --- p.14
Chapter 1.8.1 --- Phase I - Toxicity Characterization --- p.15
Chapter 1.8.2 --- Phase II - Toxicity Identification --- p.15
Chapter 1.8.3 --- Phase III - Toxicity Confirmation --- p.18
Chapter 1.9 --- Toxicity Identification Evaluation on Effluent from Textile-Dyeing Industry --- p.19
Chapter 1.10 --- Organisms Used for Toxicity Identification Evaluation --- p.20
Chapter 1.11 --- Selection of Organisms for Bioassays --- p.20
Chapter 2. --- OBJECTIVES --- p.24
Chapter 3. --- MATERIALS AND METHODS --- p.25
Chapter 3.1 --- Sources of Samples --- p.25
Chapter 3.2 --- Whole Effluent Toxicity Test - Baseline Toxicity Test --- p.28
Chapter 3.2.1 --- Microtox® test --- p.28
Chapter 3.2.2 --- "Survival test of the marine amphipod, Hyale crassicornis" --- p.29
Chapter 3.2.3 --- "Survival test of the brine shrimp, Artemia franciscana" --- p.33
Chapter 3.2.4 --- "Survival test of the freshwater water flea, Daphnia magna" --- p.36
Chapter 3.3 --- Toxicity Identification Evaluation ´ؤ Phase I Toxicity Characterization --- p.40
Chapter 3.3.1 --- pH adjustment filtration test --- p.41
Chapter 3.3.2 --- pH adjustment aeration test --- p.42
Chapter 3.3.3 --- pH adjustment cation exchange test --- p.43
Chapter 3.3.4 --- pH adjustment anion exchange test --- p.44
Chapter 3.3.5 --- pH adjustment C18 solid phase extraction (C18 SPE) test --- p.45
Chapter 3.3.6 --- pH adjustment XAD-2 solid phase extraction (XAD-2 SPE) test --- p.46
Chapter 3.4 --- Toxicity Identification Evaluation - Phase II Toxicity Identification --- p.47
Chapter 3.4.1 --- Determination of anions --- p.48
Chapter 3.5 --- Toxicity Identification Evaluation ´ؤ Phase III Toxicity Confirmation --- p.50
Chapter 3.5.1 --- Mase balance test --- p.50
Chapter 3.5.2 --- Spiking test --- p.51
Chapter 4. --- RESULTS --- p.52
Chapter 4.1 --- Characteristics of Samples --- p.52
Chapter 4.2 --- Whole Effluent Toxicity Test - Baseline Toxicity Test --- p.52
Chapter 4.2.1 --- Toxicity of effluent sample determined by the Microtox® test --- p.52
Chapter 4.2.2 --- Toxicity of effluent samples determined by Hyale crassicornis survival test --- p.52
Chapter 4.2.3 --- Toxicity of effluent samples determined by Artemia franciscana survival test --- p.57
Chapter 4.2.4 --- Toxicity of effluent samples determined by Daphnia magna survival test --- p.51
Chapter 4.3 --- Toxicity Identification Evaluation - Phase I Toxicity Characterization --- p.57
Chapter 4.3.1 --- Toxicity characterization of effluent samples determined by Hyale crassicornis survival test --- p.60
Chapter 4.3.2 --- Toxicity characterization of effluent samples determined by Artemia franciscana survival test --- p.68
Chapter 4.3.3 --- Toxicity characterization of effluent samples determined by Daphnia magna survival test --- p.68
Chapter 4.4 --- Toxicity Identification Evaluation ´ؤ Phase II Toxicity Identification --- p.72
Chapter 4.4.1 --- Baseline anion concentrations in effluent samples --- p.75
Chapter 4.4.2 --- Sample1 --- p.75
Chapter 4.4.3 --- Sample2 --- p.75
Chapter 4.4.4 --- Sample3 --- p.75
Chapter 4.4.5 --- Sample4 --- p.81
Chapter 4.4.6 --- Sample5 --- p.81
Chapter 4.4.7 --- Sample6 --- p.81
Chapter 4.5 --- Toxicity Identification Evaluation 一 Phase III Toxicity Confirmation --- p.85
Chapter 4.5.1 --- Mass balance test results --- p.85
Chapter 4.5.2 --- Spiking test results --- p.96
Chapter 5. --- DISCUSSION --- p.102
Chapter 5.1 --- Whole Effluent Toxicity Test ´ؤ Baseline Toxicity Test --- p.102
Chapter 5.1.1 --- Toxicity of effluent sample determined by the Microtox® test --- p.102
Chapter 5.1.2 --- Toxicity of effluent samples determined by Hyale crassicornis survival test --- p.103
Chapter 5.1.3 --- Toxicity of effluent samples determined by Artemia franciscana survival test --- p.104
Chapter 5.1.4 --- Toxicity of effluent samples determined by Daphnia magna survival test --- p.104
Chapter 5.2 --- Toxicity Identification Evaluation ´ؤ Phase I Toxicity Characterization --- p.105
Chapter 5.2.1 --- pH adjustment filtration test --- p.105
Chapter 5.2.2 --- pH adjustment aeration test --- p.106
Chapter 5.2.3 --- pH adjustment cation exchange test --- p.106
Chapter 5.2.4 --- pH adjustment anion exchange test --- p.106
Chapter 5.2.5 --- pH adjustment C18 solid phase extraction (C18 SPE) test --- p.107
Chapter 5.2.6 --- pH adjustment XAD-2 solid phase extraction (XAD-2 SPE) test --- p.107
Chapter 5.3 --- Toxicity Identification Evaluation - Phase II Toxicity Identification --- p.107
Chapter 5.3.1 --- Efficiency on chemical reduction of pH adjustment filtration test --- p.109
Chapter 5.3.2 --- Efficiency on chemical reduction of pH adjustment aeration test --- p.109
Chapter 5.3.3 --- Efficiency on chemical reduction of pH adjustment cation exchange test --- p.109
Chapter 5.3.4 --- Efficiency on chemical reduction of pH adjustment anion exchange test --- p.109
Chapter 5.3.5 --- Efficiency on chemical reduction of pH adjustment CI8 SPE test --- p.109
Chapter 5.3.6 --- Efficiency on chemical reduction of pH adjustment XAD-2 SPE test --- p.110
Chapter 5.4 --- Toxicity Identification Evaluation - Phase III Toxicity Confirmation --- p.110
Chapter 5.4.1 --- Mass balance test results --- p.110
Chapter 5.4.2 --- Spiking test results --- p.114
Chapter 5.5 --- Comparison of Toxicant(s) Identified in the Six Dyeing Industrial Effluents --- p.117
Chapter 5.6 --- Toxicant(s) Identified in Textile-Dyeing Industrial Effluent --- p.119
Chapter 5.7 --- "Sources, Fate and Treatment of Sulfite Ion" --- p.120
Chapter 5.8 --- Toxicity of Sulfite Ion --- p.121
Chapter 5.9 --- Effect of Salinity on the Toxicity of Sulfite Ion --- p.122
Chapter 5.10 --- Recommendation --- p.123
Chapter 6. --- CONCLUSIONS
Chapter 7. --- REFERENCES
Chapter 8. --- APPENDICES

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