A digestão anaeróbia tem se apresentado como um processo de grande interesse sob a ótica da potencial produção de energia renovável (H2 e CH4), considerando-se a ampla variedade de compostos orgânicos que podem ser utilizados. Neste estudo desejou-se avançar na compreensão do sistema de reatores anaeróbios de duas fases (acidogênico seguido de metanogênico) operados em condições termofílicas (55°C), alimentados com melaço da cana-de-açúcar, subproduto da indústria sucroalcooleira. Os experimentos foram conduzidos em reatores anaeróbios de leito fixo estruturado com fluxo ascendente e o melaço foi diluído com água de abastecimento, para adequação da concentração aos processos de tratamento de águas residuárias. Na 1ª Etapa dois reatores acidogênicos foram operados em paralelo para avaliar diferentes formas de inoculação e meios suportes, a fim de manter a produção continua e estável de hidrogênio. Para isso foram aplicadas diferentes cargas orgânicas (2,5, 5 e 10 gDQO.L-1) que resultam em COV de 30, 60 e 120 g.DQO.Lreator1.dia-1, com TDH fixo de 2 horas. A expressão do gene hidrogenase foi detectado em ambos os reatores, mas em maior proporção no reator inoculado com lodo de reator UASB e usando como material suporte a espuma de poliuretano. Sequencialmente a este reator, foi acoplado um reator metanogênico, alimentado com efluente do reator acidogênico, estabilizado nas condições apresentadas, e operado com COV crescentes de 1, 2, 5, 7, 14, 17 e 26,5 gDQO.Lreator-1.dia-1 e consequente diminuição do TDH de 240, 96, 48, 32, 24, 16 e 12 horas. O reator acidogênico na 2ª etapa foi operado por 417 dias consecutivos e COV de 120 g.DQO.Lreator1.dia-1, produzindo hidrogênio continuamente, alcançado valores de produção bruta de H2 de 7,60 LH2.dia-1. O reator metanogênico foi operado por 251 dias consecutivos, produzindo metano e alcançado valores de produção bruta de CH4 de 5,90 LCH4.dia-1. A eficiência de remoção de DQO do sistema de reatores foi de aproximadamente 90%, com contribuição aproximadamente de 10% para o reator acidogênico e contribuição aproximadamente de 80% para o reator metanogênico. O reator acidogênico alcançou rendimento de produção de hidrogênio por kg de melaço aplicado de 392 LH2.kgmelaço-1 e o reator metanogênico de 387 LCH4.kgmelaço-1. Para finalidade de comparações e aplicabilidade, o ganho energético global do sistema de reatores de duas fases foi de aproximadamente 5,7 kWh.kgmelaço-1 (1,4 kWh.kgmelaço-1 para o reator acidogênico e 4,3 kWh.kgmelaço-1 para o reator metanogênico). A produção continua de H2 obtida neste estudo está relacionada à associação das vias dos ácidos produtores de hidrogênio já consolidados pela literatura pertinente (acético e butírico) e pela produção de hidrogênio pela rota do ácido lático, devido a associação entre as comunidades de microrganismos estabelecidas no reator. O sequenciamento massivo MiSeq mostrou a seleção de diversos gêneros de microrganismos com redundância funcional e pertencentes principalmente aos Filos Firmicutes, Proteobacteria e Thermotogae, tais como Clostridium sensu stricto, Thermohydrogenium, Thermoanaerobacterium e Cellulosibacter (Firmicutes); Pseudomonas, Enterobacter, Shewanella e Petrobacter (Proteobacteria) e Fervidobacterium (Thermotogae). Microrganismos produtores de ácido lático também foram selecionados tais como: Lactobacillus, Leuconostoc, Sporolactobacillus e Trichococcus. Dos pontos de vista científico e tecnológico este estudo deu mais um passo para a compreensão dos bioprocessos envolvidos nos sistemas anaeróbios em dois estágios produzindo H2 e CH4 continuamente por longo período de tempo. / Anaerobic digestion has shown as an interesting process for renewable energy production (H2 and CH4), for a wide variety of organic compounds (carbon source). This study aimed to advance the understanding of a two-stage process anaerobic system (acidogenic bioreactor followed by methanogenic bioreactor) under thermophilic condition (55°C) fed with molasses, a sugarcane industry by-product. The experiments were conducted at up-flow structured bed reactors and sugarcane molasses was diluted with tap water, to adjust the concentration to the wastewater treatment. At first stage two acidogenic reactors were operated in parallel to evaluate different source of inocula and support bed, to obtain continuous and stable hydrogen production. It was applied 2.5, 5 and 10 gCOD.L-1 resulting in OLR of 30, 60 and 120 g.COD.Lreactor-1.day-1, with HRT fixed at 2 hours of hydrogenase gene was detected in both reactors but with higher number of copies of the gene in the reactor that showed higher hydrogen production: the reactor sed with sludge of UASB reactor and using polyurethane foam as support material. To this reactor was coupled a methanogenic reactor fed with effluent from acidogenic reactor and operated with increasing OLR (1, 2, 5, 7, 14, 17 e 26,5 gCOD.Lreactor-1.day-1) decreasing the HRT (240, 96, 48, 32, 24, 16 and 12 hours). The acidogenic reactor was operated during 471 days with OLR of 120 g.COD.Lreactor-1.day-1, with HRT fixed at 2 hours, with continuous hydrogen production with a gross production of 7.60 LH2.day-1. The methanogenic reactor was operated for 251 days, with continuous methane production of up to 5.90LCH4.day-1. The COD removal efficiency using the two-stage system was approximately 90% , with 10% contribution by the acidogenic reactor and 80% contribution by the methanogenic reactor. The acidogenic reactor achieved hydrogen yield per kg of applied molasses equal to 392 LH2.kgmolases-1. The methanogenic reactor achieved methane yield per kg of applied molasses equal to 387 LCH4.kgmolasses-1. For comparison and applicability purposes, the overall energy yield using the two stage reactor system was approximately 5.7 kWh.kgmolasses-1 (Acidogenic reactor 1.4 kWh.kgmolasses-1 and Methanogenic reactor 4.3 kWh.kgmolasses-1). The continuous production of H2 obtained in this study is related to the association of the hydrogen producer acids pathway established by the relevant literature (acetic and butyric) and the hydrogen production by the lactic acid pathway due to the microorganisms association established in the reactor. Metagenomic analysis by MiSeq Plataform revealed that hydrogen production was due the selection of microorganisms with functional redundancy mainly of Phyla Firmicutes, Proteobacteria and Thermotogae, such as Clostridium sensu stricto, Thermohydrogenium, Thermoanaerobacterium, Cellulosibacter (Firmicutes); Pseudomonas, Enterobacter, Shewanella and Petrobacter (Proteobacteria) and Fervidobacterium (Thermotogae). Genera of acid latic producers, such as Lactobacillus, Leuconostoc, Sporolactobacillus and Trichococcus, were also selected. From the scientific and technological point of view this study has taken another step towards the understanding of bioprocesses involving two stage anaerobic systems for a long term continuous production of H2 and CH4.

Orientadores: Rosana Aparecida Baeninger, Cláudio Salvadori Dedecca / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciências Humanas / Made available in DSpace on 2018-08-20T02:58:26Z (GMT). No. of bitstreams: 1 Oliveira_RicardoAntunesDantasde_D.pdf: 2476858 bytes, checksum: 3e574f8dd7aa7c976f8e00dadf8d16e9 (MD5) Previous issue date: 2012 / Resumo: Esta tese analisa as características, tendências e expressões regionais da mobilidade espacial dos cortadores de cana no estado de São Paulo, com o objetivo de compreender suas articulações aos processos multi-escalares que estruturam o Complexo Agroindustrial (CAI) canavieiro nas regiões de Ribeirão Preto e Presidente Prudente. As questões são abordadas a partir do conceito de divisão espacial do trabalho, que possibilita abordar tanto as dinâmicas regionais do complexo canavieiro, quanto às distintas formas de articulação da mobilidade espacial a estas. São utilizados os seguintes procedimentos metodológicos: revisão bibliográfica relativa às diversas questões abordadas; trabalho com diversas fontes de informações estatísticas, especialmente Censo Demográfico 2000, Pesquisa Nacional por Amostra de Domicílios (PNAD) em suas versões para a década de 2000, mesmo período para o qual são considerados os dados do Relatório Anual de Informações Sociais (RAIS) do Ministério do Trabalho e Emprego; e, trabalho de campo nas regiões de Ribeirão Preto e Presidente Prudente, voltado principalmente à realização de entrevistas qualitativas com os cortadores de cana. A expansão das atividades canavieiras durante a década de 2000, vinculada à introdução dos veículos flex-fuel no Brasil e às boas possibilidades de exportação do etanol e do açúcar, significou um aumento do número de trabalhadores. Em função da histórica importância dos trabalhadores migrantes, originários de algumas das regiões mais pobres, para o mercado de trabalho do complexo, se registra o aumento da quantidade de pessoas envolvidas nos fluxos, marcados pelo aumento da diversidade das origens que se expressam distintamente nas regiões produtoras. Embora não configure uma novidade em termos de deslocamento populacional, a mobilidade dos cortadores de cana tem suas espacialidades transformadas. Regiões de origem específicas e múltiplas áreas de destino, lugares e atividades econômicas diversas, constituem uma mobilidade circular, que estrutura territórios circulatórios, integrando perspectivas macro e micro, além da questão das redes. No âmbito das dinâmicas regionais de Ribeirão Preto e Presidente Prudente, verifica-se que a mobilidade dos cortadores de cana expressa diferenciações quanto à articulação do CAI canavieiro e se coloca como estruturadora de inserções e posições dos centros urbanos nas redes regionais. A partir dos resultados obtidos, busca-se contribuir para os debates relativos às causas, motivações e efetivação da mobilidade circular no contexto da mobilidade espacial da população no momento histórico atual, além da questão regional. São demonstrados os impactos sociais da expansão das atividades canavieiras, muitas vezes encobertos pelo apelo dos biocombustíveis e das possibilidades de exportação. Nesse sentido, apresentam relevância no sentido da reflexão sobre os rumos que o processo de desenvolvimento econômico vem tomando no Brasil e como a sociedade o vem considerando / Abstract: This dissertation analyses the characteristics, tendencies and regional expressions of sugarcane cutters? spatial mobility in São Paulo state, in order to understand its articulations to the multi-scale processes that structure the sugarcane Agro-industrial Complex in Ribeirão Preto's and Presidente Prudente's regions. The questions are addressed through the concept of spatial division of labor, which allows approaching the regional dynamics of the sugarcane complex and the various forms of articulation of spatial mobility to those. The following procedures are used: bibliographical revision, concerning the different questions addressed; quantitative work with information from various sources, especially IBGE Demographic Census 2000, Pesquisa Nacional por Amostra de Domicílios (PNAD) for the 2000's decade, same period of data from Relatório Anual de Informações Sociais (RAIS) of Ministério do Trabalho e Emprego; and, fieldwork at the Ribeirão Preto's and Presidente Prudente's regions, directed primarily to qualitative interviews with the sugarcane cutters. The expansion of sugarcane activities during 2000?s decade, related to flex-fuel vehicles introduction in Brazil and the good possibilities of ethanol and sugar exportation, meant an increment in the number of workers. Considering the historical importance of migrant workers, from some of the poorest regions of the country, to the complex labor market, a growth in the number of people involved in the flows is observed, a process characterized by an increase of origins diversity, which has distinct expressions in the production regions. Although not being a novelty in terms of population displacement, the sugarcane cutters mobility has its spatialities transformed. Specific origin regions and multiple destination areas, diverse places and economic activities constitute a circular mobility, which structure circulatory territories, integrating macro and micro perspectives and the migrant network question. Concerning the regional dynamics of Ribeirão Preto and Presidente Prudente, it is observed that the sugarcane cutters mobility expresses distinctions regarding the sugarcane Agro-industrial Complex articulations and puts itself as a structuring part of urban centers insertions and positions in regional nets. From the results obtained, the following contributions are searched: the debate around causes, motivations and effectuation of circular mobility on the context of population spatial mobility in recent historical period; and the regional question. The social impacts of sugarcane activities expansion are shown, questions that a lot of times are obscured by the biofuels appeal and the exportation possibilities This way, it is relevant considering the reflections about the directions the economic development processes are taking in Brazil and how the society has been considering it / Doutorado / Demografia / Doutor em Demografia

Orientador: Andréia Galvão / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciências Humanas / Made available in DSpace on 2018-08-20T06:37:21Z (GMT). No. of bitstreams: 1 Correa_E.G._M.pdf: 1300324 bytes, checksum: e5fd61768463060381bc90c713d33c3c (MD5) Previous issue date: 2012 / Resumo: Neste trabalho, nosso objetivo consiste em analisar os aspectos fundamentais da ação do Sindicato de Empregados Rurais de Cosmópolis, município localizado no interior do Estado de São Paulo, diante da intensificação da mecanização da colheita da cana-de-açúcar pela Usina Açucareira Ester S/A na década de 2000. Este sindicato logrou uma ação reivindicativa relevante junto aos trabalhadores canavieiros no final dos anos 1990, a qual culminou na implantação de um sistema de controle da produção no corte da cana denominado Quadra Fechada, que tinha como característica principal a presença constante do sindicato nos locais de trabalho. No entanto, a expansão da colheita mecanizada e o aumento do desemprego entre os assalariados rurais afetaram negativamente a organização sindical destes trabalhadores, na medida em que resultaram no distanciamento entre estes e seus dirigentes sindicais e no desaparecimento da atividade sindical nos locais de trabalho. Para compreender a ação do SER-Cosmópolis, que incorporou alguns elementos do discurso neoliberal, analisamos a sua inserção junto aos trabalhadores, as orientações político-ideológicas de suas lideranças, as táticas e formas de luta escolhidas em resposta ao atual contexto de desemprego, assim como a forma como os trabalhadores a enxergam. Realizamos uma pesquisa qualitativa que contemplou a leitura da bibliografia pertinente ao tema, a consulta de documentos sindicais e entrevistas semiestruturadas com os trabalhadores canavieiros, com os funcionários do corpo gerencial da Usina Ester e com lideranças do SER-Cosmópolis / Abstract: In this work, our goal is to analyze the fundamental aspects of the action of the Rural Workers Trade Union of Cosmópolis, a municipality in Sao Paulo State, after the intensification of mechanization in sugarcane harvesting process in Ester Sugar Mill S/A in the 2000s. The union achieved a significant share of the demands of the sugarcane harvesting workers in the late 90s, assuring the establishment of a system of production control in the sugarcane fields called Quadra Fechada (Closed Court), which had as it main feature the constant presence of the union at workplace. However, the expansion of mechanized harvesting and rising unemployment among rural workers negatively affected their trade union organization, creating a gap between them and their union leaders and disappearing the trade union activity at workplace. To understand the action of Rural Workers Trade Union of Cosmópolis - which adopted some elements of neoliberal discourse - we analyze its relationship to sugarcane harvesting workers, the politicalideological orientation of its leaders, their tactics and forms of struggle chosen in response to the current context of unemployment as well as how workers see their union and leaders. We performed a qualitative study that included the reading of the pertinent literature, consultation of union documents and conducting semi-structured interviews with sugarcane workers and employees of the management of Ester Sugar Mill and leaders of the Rural Workers Trade Union of Cosmópolis / Mestrado / Ciencia Politica / Mestre em Ciência Política

The purpose of this paper was to examine the competitiveness of the South African sugar industry relative to the top ten exporters of the product, namely Brazil, Thailand, Netherlands, Mexico, China, Germany, Canada, France, Belgium and the United States of America. Different techniques were used in the study to ensure that the main objective of the study was achieved. Three popular indices, namely the Balassa Revealed Comparative Advantage (RCA#) Index, the Net Export Index (NXi) and the Relative Revealed Comparative Trade Advantage (RTA) Index were used to compare the competitiveness of the top ten sugar exporting countries including South Africa. The Trade Potential Index was also applied in the study to investigate markets that South Africa could use to increase its exports. Time series data collected on the trade map and the Food and Agricultural Organization of the United Nations were used for the analysis of the markets by using an Excel spreadsheet. The results of the study showed that South Africa has a trade competitive advantage against the majority of the countries considered. South Africa's competitive performance was surpassed by that of Brazil, which was the strongest trader of sugar, followed by Thailand and China. The remaining seven countries (Mexico, Belgium, Netherlands, Canada, Germany, USA and China) were all exceeded by the South African sugar industry. The top potential markets that South Africa could exploit to increase its exports were identified with the use of the Trade Potential Index (TPI). The countries that were identified were selected by calculating the scores, comparing tariffs imposed by these markets to the exporters of sugar and looking at the concentration of the markets that supply these potential markets. The United States of America, Lesotho, Democratic Republic of Congo, Malawi and Egypt were identified as the top five countries that South Africa could exploit for its sugar exports. South Africa has trade agreements with the majority of these countries which assist the country in obtaining preferential agreements when exporting its products to these countries. Recommendations were made that could help the sugar industry to grow its competitiveness. / Inhloso yaleliphepha bekukuhlola kuncintisana kwemboni yashukela yaseNingizimu Afrika nayicatsaniswa nebatfumeli ngaphandle labasembili labalishumi balomkhicito, lekuyiBrazil, iThailand, iNetherlands, iMexico, iChina, iGermany, iCanada, iFrance, iBelgium ne-United States of America. Kusetjentiswa emasu lahlukene kulesifundvo kucinisekisa kutsi inhloso lenkhulu yesifundvo iyaphunyelelwa. Kusetjentiswe ema-indice, lekuyi-Balassa Revealed Comparative Advantage (RCA#) Index, i-Net Export Index (NXi) kanye ne-Relative Revealed Comparative Trade Advantage (RTA) Index kucatsanisa kuncintisana kwalamave lasembili lalishumi lakhicita shukela kufaka ekhatsi eNingizimu Afrika. I-Trade Potential Index nayo isetjentisiwe kulesifundvo kuphenya timakethe letingasetjentiswa yiNingizimu Afrika kute ikhulise kutfumela ngaphandle kwayo lomkhicito washukela. Idatha yeluchungechunge lwesikhatsi legcogcwe kulibalave lekuhwebelana kanye naseNhlanganweni Yekudla Neyetekulima yaMhlab'uhlangene isetjentisiswe kuloluhlatiyo lwetimakethe ngekusebentisa si-spreadsheet se-Excel. Imiphumela yesifundvo ikhombise kwekutsi iNingizimu Afrika inekusitakala ngekuncintisana ekuhwebeni nayicatsaniswa nelinyenti lalamave lamanyenti lahlatiyiwe. Kusebenta kwekuncintisana kweNingizimu Afrika kundlulwe kusebenta kweBrazil, lebeyingumhwebi lomkhulu washukela, ilandzelwe yiThailand kanye neChina. Lamave lasikhombisa lasele (iMexico, iBelgium, iNetherlands, iCanada, iGermany, i-USA neFrance) onkhe andlulwe yimboni yashukela yaseNingizimu Afrika. Timakethe letingaba khona letiphambili leti iNingizimu Afrika ingatisebentisa kukhulisa kutfumela ngaphandle kwayo tibonwe ngekusebentisa iTrade Potential Index (TPI). Emave laboniwe akhetfwe ngekubala imiphumela, kucatsanisa ematharifu lafakwe nguletimakethe kubatfumeli bangaphandle bashukela nekubuka kulokucocana kwetimakethe lephakela letimakethe letingaba khona. I-United States of America, iLesotho, iDemocratic Republic of Congo, iMalawi ne-Egypt abonwe njengemave lasembili lasihlanu langasetjentiswa yiNingizimu Afrika kutfola ngaphandle shukela wayo. INingizimu Afrika inetivumelwano tekuhwebelana nelinyenti lalamave lokusita lelive ekutfoleni tivumelwano tekubekwa ngembili nangabe kutfunyelwa ngaphandle imikhicito yayo kulamave. Tiphakamiso letingasita imboni yashukela kukhulisa kuncintisana kwayo tentiwe. / Inhloso yalo mbhalo wocwaningo kwabe kuwukucubungula nokuhlaziya amandla okuncintisana ngempumelelo kwemboni kashukela yaseNingizimu Afrika uma iqhathaniswa namazwe ayishumi ahamba phambili emhlabeni ekuthumeleni imikhiqizo kashukela emazweni angaphandle, okuyi-Brazil, Thailand, Netherlands, Mexico, China, Germany, Canada, France, Belgium kanye neMelika (USA). Kulolu cwaningo kwasetshenziswa izindlela ezihlukahlukene ngenhloso yokuqinisekisa ukufezekiswa kwenjongo enkulu yocwaningo. Kwasetshenziswa izinkomba-simo ezintathu ezidumile futhi okuyizona ezisetshenziswa kakhulu, okuyi-Balassa Revealed Comparative Advantage (RCA#) Index, Net Export Index (NXi) kanye ne-Relative Revealed Comparative Trade Advantage (RTA) Index ukuqhathanisa amandla okuncintisana ngempumelelo kwamazwe ayishumi ahamba phambili emhlabeni ekuthumeleni ushukela emazweni angaphandle, kubandakanya neNingizimu Afrika. I-Trade Potential Index yasetshenziswa futhi nayo kulolu cwaningo ukuphenya nokucubungula izimakethe ezingasetshenziswa yiNingizimu Afrika ukukhulisa inani lemikhiqizo yayo ethunyelwa emazweni angaphandle. Idatha eqoqwe ochungechungeni lwamaqophelo alandelana ngokwesikhathi ebalazweni lokuhwebelana kanye naseNhlanganweni Yokudla NezolimoyeNhlangano Yezizwe yasetshenziselwa ukuhlaziya izimakethe ku-Excel spreadsheet. Imiphumela yocwaningo yabonisa ukuthi iNingizimu Afrika isesimweni esikahle futhi inamandla angcono okuncintisana ngempumelelo kwezohwebo uma iqhathaniswa neningi lamazwe acutshungulwayo. Amandla eNingizimu Afrika okuncintisana ngempumelelo adlulwa yilawo e-Brazil, okuyizwe elinamandla kakhulu futhi elihamba phambili kwezokuhwebelana ngoshukela, kulandele i-Thailand kanye ne-France. Imboni kashukela yaseNingizimu Afrika inamandla angaphezulu kwawo wonke lawa amanye amazwe asele ayisikhombisa (okuyi-Mexico, Belgium, Netherlands, Canada, Germany, USA kanye ne-China). Amazwe ahamba phambili angasetshenziswa yiNingizimu Afrika ekukhuphuleni umthamo wemikhiqizo yayo ethunyelwa emazweni angaphandle ahlonzwa ngokusebenzisa i-Trade Potential Index (TPI). Lawo mazwe ahlonziwe akhethwe ngokubala inani lamaphuzu, ukuqhathanisa intela yempahla ekhokhiswa yilawo mazwe emazweni angaphandle athumela ushukela kanye nokubheka ubuningi bamazwe athumela imikhiqizo yawo kulawo mazwe angasetshenziswa yiNingizimu Afrika ukukhulisa umthamo wemikhiqizo yawo ethunyelwa emazweni angaphandle. I-USA, Lesotho, Democratic Republic of Congo, Malawi kanye ne-Egypt ahlonzwa njengamazwe aphuma phambili iNingizimu Afrika engathumela kuwona ushukela. INingizimu Afrika inezivumelwano zokuhwebelana neningi lalawa mazwe, okuyizivumelwano eziyilekelelayo ekutholeni izivumelwano ezizokwenza ibhekelelwe kangcono futhi icatshangelwe uma ithumela imikhiqizo yayo kulawa mazwe angaphandle. Kwenziwa izincomo ezingayilekelela imboni kashukela ukuthi ikwazi ukukhulisa amandla ayo okuncintisana ngempumelelo. / Agriculture and  Animal Health / M. Sc. (Agriculture)

La vinasse de distillerie, co-produit de l’industrie canne-sucre-alcool-énergie, contient de 5 à 7 g/L d’un acide d’intérêt, l’acide aconitique, au sein d’un milieu complexe comportant d’autres acides organiques, des acides aminés, mais surtout des sels minéraux (chlorures et sulfates) et des colorants, rendant sa purification complexe. Afin d’améliorer les performances du procédé d’échange d’ions, au coeur de cette purification, la résine anionique faible Lewatit S4528 a été caractérisée. Le dosage de la résine et des mesures d’isothermes d’échange d’ions ont permis de définir : la capacité totale du support, l’ordre d’affinité des principaux anions de la vinasse et les coefficients d’échange d’ions associés, de même que la capacité pour l’acide d’intérêt dans cette matrice complexe. L’effet du pH, de la forme du support (sulfate, chlorure et base libre) et de l’éluant ont été étudiés en colonne pour différentes solutions (acide seul, vinasse « modèle », vinasse réelle), permettant de préciser les mécanismes de la purification.Les meilleures conditions (vinasse à pH 4,5, résine sous forme chlorure et élution par HCl 0,5 N) ont abouti à un éluat d’une pureté de 28 %MS avec un rendement global de 61 %. Pour éliminer les principales impuretés qui persistent dans l’éluat (ions chlorure et sulfate et des colorants), l’électrodialyse s’est avérée un procédé très performant en ce qui concerne l’élimination des ions chlorure (proche de 100 %) tandis qu’une étape d’adsorption sur résine polystyrénique XAD16 permet l’élimination de 80 % de la charge colorante de l’éluat acide. Le couplage le plus intéressant associe microfiltration, échange d’ions, électrodialyse et adsorption. Il permet d’obtenir une pureté estimée à 37 % MS, avec un facteur de purification de 3,6 par rapport à la vinasse initiale. Ces travaux ont permis d’améliorer d’un facteur 2,6 la pureté de l’acide par rapport à des études antérieures et de mieux comprendre les mécanismes de sa purification sur résine anionique faible. / Cane stillage or vinasse, a byproduct of cane industry, contains from 5 to 7 g/L of aconitic acid, a valuable trivalent carboxylic acid belonging to the second class of building block chemicals. Vinasse also contains a variety of organic compounds (organic acids, amino-acids, colouring matters) and minerals (chlorides, sulphates), which makes purification not straightforward. The objective of this work is to develop the extraction of aconitic acid from stillage, with anion exchange as the heart of the process. In order to improve performances, the main characteristics of the selected anion-exchange resin (Lewatit S4528) are studied. Acid-base dosage and ion-exchange equilibrium experiments allow the total capacity of this support and the ion-exchange coefficients for the major competing anions (aconitate, chloride and sulfate) to be obtained. Separation performances in column are studied for different pH, different solutions (aconitic acid alone, synthetic and industrial stillage) and different resin forms (sulfate, chloride and free- base) in order to elucidate the separation mechanisms.Elution step is also investigated. Best conditions are for stillage at its natural pH (pH 4.5) on the resin under chloride form and HCl 0,5N as the eluant. A 28% DM purity and a 61% global recovery are achieved for aconitic acid in the eluate. Main impurities still remaining are chlorides or sulfates and coloring matter. Homopolar electrodialysis proves successful for removing nearly 100% chlorides from aconitic acid with a limited loss of the acid (< 15%). Adsorption step on a polystyrenic resin (XAD16) of an acidic eluate leads to the retention of 80% of the colorants, with only 12% of the acid lost. At last, the most interesting process combination associates microfiltration, anion-exchange, electrodialysis and adsorption. Purity is 37% MS, namely 3.6 higher than the original vinasse. This work enables aconitic acid purity to be improved by a factor of 2.6 compared with prior studies and to have a better comprehension of the mechanisms involved in its purification on weak anionic resin.

Orientador: Fernando Antonio Lourenço / Dissertação (mestrado) - Universidade Estadual de Campinas, Intituto de Filosofia e Ciências Humanas / Made available in DSpace on 2018-08-17T04:07:07Z (GMT). No. of bitstreams: 1 Guanais_JulianaBiondi1985-_M.pdf: 1924997 bytes, checksum: 1e82d201be630117858ee74e6bd332fe (MD5) Previous issue date: 2010 / Resumo: Partindo de um estudo de caso, focalizado na Usina Açucareira Ester S.A. (localizada em Cosmópolis, interior de São Paulo), a presente pesquisa tem como objetivo central a análise do Quadra fechada, um sistema alternativo de aferição da quantidade de cana cortada, que foi implantado somente na referida usina, em 1998, após um processo de negociação entre a mesma e o Sindicato dos Empregados Rurais de Cosmópolis. Assim, ao longo da dissertação, são abordadas temáticas relacionadas ao Quadra fechada, tais como: a histórica reivindicação dos trabalhadores assalariados rurais para controlarem sua produção, demanda essa de extrema importância e que está intimamente associada ao pagamento por produção, forma de remuneração que atrela o salário dos trabalhadores rurais à quantidade de cana cortada por eles. A pesquisa teve como base a perspectiva relacional, e buscou analisar as estratégias dos diferentes agentes sociais envolvidos com o Quadra fechada, quais sejam: os representantes da Usina Ester, seus cortadores de cana, e os dirigentes do Sindicato dos Empregados Rurais de Cosmópolis. Juntamente com as entrevistas realizadas, buscou-se observar as práticas e as condutas dos agentes sociais, observações essas que serviram como aporte para todo o trabalho de contextualização dos relatos colhidos / Abstract: Based on a fieldwork case developed at the Ester S.A. sugar cane mills (at Cosmópolis, countryside of São Paulo State, Brazil) the research presented here has as a central goal the analyses of Quadra Fechada (closed court), that is an alternative system to measure the total quantity of cane cut. This measurement system is working solely at Ester S.A. and is the result of a negotiation between the industry and the Rural Workers Union of Cosmópolis in 1998. Therefore, will be part of this thesis subject some kind of discussion and debates related to Quadra Fechada as for example: The historical cane cutters claim for controlling their production, that is an extremely important demand because deals directly with the system that associates the payment amount with production quantity; and also the debate of the system itself that directly relate payment amount with the quantity of cane cut. Besides that the research was built at a relational perspective made clear by the analyses of the different social agents involved with Quadra Fechada strategies as: Ester Mills representatives, its sugar cane cutters, and the Rural Workers Union leaders. The main interest was to observe the practices and conducts/manners of the social agents at the fieldwork. Those observations were of tremendous importance as they served as contribuition to the hole contextualization of the reports collected as interviews or orally / Mestrado / Sociologia Rural / Mestre em Sociologia