Up to 30% by mass of plant cell walls are comprised of hemicelluloses. The remainder is comprised of cellulose, lignin and extractives. Potential economic uses of hemicellulose include hydrogels, fibre additives in pulp mill paper-making and as a substrate for fermentation processes. Development of a fermentation process with sugars from hemicellulose has become of increasing interest due to their potential as a feedstock for fermentation-based liquid fuels and other bio-based chemicals. These can be incorporated into existing processes, in particular alkaline chemical pulping mills, where up to 50% of the hemicelluloses are today degraded and eventually combusted. The main objective of this project is to examine the solubility and aggregation properties of xylans (the predominant hemicellulose), as this will hopefully lead to better solubility-based separations for their recovery. This was done at Michigan State University by alkaline extraction at 85°C on milled birch wood, and at 130 and 170°C (both time-dependent) on birch chips, with 50 g/L sodium hydroxide. This was then followed by precipitation/aggregation experiments with ethanol, polyDADMAC (a polycationic flocculant) and by acidification. Characterisation was done by performing dynamic light scattering (DLS) and size exclusion chromatography (SEC) analysis on resolubilised recovered material from the different extraction conditions. From these, size distributions, molecular weights and degrees of polymerization (DP) could be estimated. The DP values for the extracted polymers were higher than the expected values for hardwood xylans, owing to the incoherent SEC chromatograms. This may be due to aggregate formation with other polymers or re-solubilisation issues of the hemicellulose precipitates. The estimated size range for model xylan was between 100 to 300 nm and the ethanol precipitates seemed to also lie around this region, as detected by DLS. One of the major factors contributing to the difficulty of analysing the results was the issue of re-solubilisation of the hemicellulose precipitates and flocculates. / <p>Validerat; 20120827 (anonymous); 2017-02-08 Nedladdad 414 gånger t.o.m. september 2016. Downloaded 414 times up until september 2016 (marisr)</p>

Orientador: Tsunao Matsumoto / Banca: Edson Pereira Tangerino / Banca: Marcelo Libânio / Resumo: Na busca de avanços na concepção de uma Estação de Tratamento de Água (ETA) mais eficiente construiu-se, estudou-se e testou-se um Módulo Floco Decantador de Manta de Lodo (MFDML) - escala modelo. Essa busca contou com várias etapas e processos que envolveram uma ampla e variada pesquisa bibliográfica para a formação de idéias que foram ou poderão ser colocadas em prática para melhores calibração e verificação. Os avanços no MFDML forneceram resultados que motivaram seu estudo em escala de protótipo, denominado Sistema Floculador de Manta de Lodo (SFML) na forma de um Protótipo Modular Compacto (PMC) automatizado que pudesse ser operado de forma integrada aos diversos monitoramentos dos recursos hídricos. As idéias pesquisadas e estudadas geraram metodologias de cálculo que permitem a utilização prática do SFML, obtenção prévia de dosagens a partir de jar-test, estimativa da quantidade de lodo formada e estabelecimento de correlações qualitativas para aumento de escala. O SFML possui uma tecnologia com taxas de decantação 10 vezes maior que as tecnologias atuais (400m 3 /m 2 /dia) associados a bons resultados em termos de remoção de sólidos suspensos e dissolvidos, com turbidez da água decantada da ordem de 3uT e da filtrada de 0,1uT. No entanto, um maior desenvolvimento dessa nova tecnologia poderá ocorrer no âmbito científico-tecnológico conforme as necessidades e o despertar de idéias para contemplá-las. Assim, a busca por conhecimentos e melhoramentos científico-tecnológicos é um processo dinâmico, o qual envolve tempo, dedicação e continuidade das pesquisas. / Abstract: On improvements search of the Water Treatment Plant more efficient conception was build, studied and tested a Sludge Blanket Flocculate Setter Modular Model. This search has been several processes and steps involved a varied and ample bibliographic search for ideas formation that was or will be set in practice for true verification and calibration. The improvements at the Sludge Blanket Flocculate Setter Modular Model gave results have motivated its prototype scale study, called Sludge Blanket Flocculator System in a Automated Compact Modular Prototype that could be operated in a integrated way with both waters resources managements and monitoring. These ideas generated calculation methodologies that may the Sludge Blanket Flocculator System for practice utilization, previous of dosages whith jar-test, formed sludge quantity estimate and scale increase correlations qualitative establishment. The Sludge Blanket Flocculator System owns a technology with settling rates 10 larger times than the current technologies (400m 3 /m 2 /dia) associates the good results in terms of suspended and dissolved solid removal, with water turbidity about 3uT and of the filtrated about 0,1uT. However, a more development of this new methodology may happen in a scientific-technology environ accord to the ideas necessities and emerge to get it. Thus, technologies-scientifics improvements and knowledge search is a dynamic process, which involves the research spend time, dedication and keep on of these. / Mestre

Made available in DSpace on 2014-06-11T19:29:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-05-26Bitstream added on 2014-06-13T18:58:47Z : No. of bitstreams: 1 cavazzana_tl_me_ilha.pdf: 2979174 bytes, checksum: 3a1c33ad1723fd5eb6eef680e02d054b (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Na busca de avanços na concepção de uma Estação de Tratamento de Água (ETA) mais eficiente construiu-se, estudou-se e testou-se um Módulo Floco Decantador de Manta de Lodo (MFDML) - escala modelo. Essa busca contou com várias etapas e processos que envolveram uma ampla e variada pesquisa bibliográfica para a formação de idéias que foram ou poderão ser colocadas em prática para melhores calibração e verificação. Os avanços no MFDML forneceram resultados que motivaram seu estudo em escala de protótipo, denominado Sistema Floculador de Manta de Lodo (SFML) na forma de um Protótipo Modular Compacto (PMC) automatizado que pudesse ser operado de forma integrada aos diversos monitoramentos dos recursos hídricos. As idéias pesquisadas e estudadas geraram metodologias de cálculo que permitem a utilização prática do SFML, obtenção prévia de dosagens a partir de jar-test, estimativa da quantidade de lodo formada e estabelecimento de correlações qualitativas para aumento de escala. O SFML possui uma tecnologia com taxas de decantação 10 vezes maior que as tecnologias atuais (400m 3 /m 2 /dia) associados a bons resultados em termos de remoção de sólidos suspensos e dissolvidos, com turbidez da água decantada da ordem de 3uT e da filtrada de 0,1uT. No entanto, um maior desenvolvimento dessa nova tecnologia poderá ocorrer no âmbito científico-tecnológico conforme as necessidades e o despertar de idéias para contemplá-las. Assim, a busca por conhecimentos e melhoramentos científico-tecnológicos é um processo dinâmico, o qual envolve tempo, dedicação e continuidade das pesquisas. / On improvements search of the Water Treatment Plant more efficient conception was build, studied and tested a Sludge Blanket Flocculate Setter Modular Model. This search has been several processes and steps involved a varied and ample bibliographic search for ideas formation that was or will be set in practice for true verification and calibration. The improvements at the Sludge Blanket Flocculate Setter Modular Model gave results have motivated its prototype scale study, called Sludge Blanket Flocculator System in a Automated Compact Modular Prototype that could be operated in a integrated way with both waters resources managements and monitoring. These ideas generated calculation methodologies that may the Sludge Blanket Flocculator System for practice utilization, previous of dosages whith jar-test, formed sludge quantity estimate and scale increase correlations qualitative establishment. The Sludge Blanket Flocculator System owns a technology with settling rates 10 larger times than the current technologies (400m 3 /m 2 /dia) associates the good results in terms of suspended and dissolved solid removal, with water turbidity about 3uT and of the filtrated about 0,1uT. However, a more development of this new methodology may happen in a scientific-technology environ accord to the ideas necessities and emerge to get it. Thus, technologies-scientifics improvements and knowledge search is a dynamic process, which involves the research spend time, dedication and keep on of these.