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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Humic acid production by fermentation of waste from palm oil processing using Trichoderma strains = Produção de ácidos húmicos por fermentação de resíduos do processamento de óleo de palma utilizando cepas de Trichoderma / Produção de ácidos húmicos por fermentação de resíduos do processamento de óleo de palma utilizando cepas de Trichoderma

Motta, Fernanda Lopes, 1983- 23 August 2018 (has links)
Orientador: Maria Helena Andrade Santana / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-23T11:23:21Z (GMT). No. of bitstreams: 1 Motta_FernandaLopes_D.pdf: 3417734 bytes, checksum: 1bedbddf5299dc8332b4762b7c232081 (MD5) Previous issue date: 2013 / Resumo: Ácidos húmicos (AH) são macromoléculas orgânicas de alta complexidade estrutural. Na agricultura, seus efeitos diretos na produtividade e na qualidade de diversos cultivos têm sido explorados desde 1940 e na última década houve um grande crescimento no seu emprego na medicina e na biologia. Embora suas inúmeras aplicações tenham atraído a atenção de muitos pesquisadores, os AH comerciais são ainda extraídos da turfa e do carvão mineral, fontes não renováveis de carbono, indicando a necessidade do desenvolvimento de um processo biotecnológico para sua produção. Empty-fruit-bunches (EFB) são resíduos do processamento do óleo de palma subutilizados ou descartados. Além disso, EFB são fibras constituídas de celulose, hemicelulose e lignina, cuja degradação pode ser alcançada por meio da ação de micro-organismos com alta capacidade de degradação de material lignocelulósico, como o Trichoderma. Neste contexto, este trabalho visou produção de AH a partir da fermentação de EFB com cepas de Trichoderma. Os resultados obtidos demonstraram que aveia é um substrato adequado para produção de esporos de Trichoderma em profundidade para sua aplicação como inóculo das fermentações submersas (FS) de EFB para produção de AH. A investigação dos precursores dos AH dentre os polímeros constituintes do EFB indicaram um efeito sinergético destes polímeros. Quanto à substituição do extrato de leveduras por peptonas vegetais nos meios de cultivo, para ambas fontes de nitrogênio os resultados encontrados para produção de biomassa e de AH foram muito similares. Através da otimização da produção dos AH por FS utilizando ferramentas de planejamento experimental foram obtidos 428,4±17,5 mg/L destes ácidos, permitindo um aumento de 7 vezes em relação às condições inicialmente utilizadas neste trabalho. A comparação da performance de espécies de Trichoderma na produção de AH por FS indicou a superioridade do T. reesei na produção destes ácidos. Por fim, a caracterização do processo de produção dos AH por fermentação em estado sólido (FES) utilizando colunas de Raimbault, onde foram obtidos 88,1 ±2,9 mg/L destes ácidos, confirmou a relação entre a esporulação do fungo e a produção dos AH, assim como a hipótese do efeito sinérgico dos polímeros. Os resultados obtidos demonstraram a factibilidade da produção dos AH por processos fermentativos, cuja descrição na literatura ainda é muito limitada, o que confere a este trabalho um caráter inovador / Abstract: Humic acids (HA) are organic macromolecules of high structural complexity. In agriculture, their direct effects on yield and quality of many crops have been exploited since 1940 and the last decade there was a large increase in their use in medicine and biology. Although they have attracted the attention of many researchers due to their numerous applications, commercials AH are still extracted from peat and coal, non-renewable carbon sources, indicating the necessity to develop a biotechnological process for their production. Empty-fruit-bunches (EFB) are waste of oil palm processing, which are underutilized or discarded, and their accumulation brings environmental problems due to the attraction and proliferation of pests. In addition, EFB fibers are composed of cellulose, hemicellulose and lignin, whose degradation can be achieved by the action of microorganisms with high capacity of lignocellulosic material degradation, such as Trichoderma. In this context, this work aimed to produce HA from the fermentation of EFB with Trichoderma species. The results showed that oats is a suitable substrate for the production of Trichoderma spores to be used as inoculum for application in submerged fermentations (SF) of EFB for the HA production. The investigation of the HA precursor among the constituents polymers from the EFB indicate a synergistic effect of these polymers. Regarding the replacement of yeast extract by vegetable peptones in the culture medium, for both nitrogen sources the results in the production of biomass and HA were very similar. Through the optimization of the HA production by SF using experimental design, were obtained 428.4 ± 17.5 mg/L of these acids, allowing an increase of 7-fold compared to initial conditions used in this work.. A comparison of the performance of Trichoderma species in the HA production by FS indicated the superiority of the T. reesei in the production of these acids. Finally, characterization of HA production process by solid state fermentation (SSF) using Raimbault columns, where were obtained 88.1 ±2.9 mg/L of these acids, confirmed the relationship between the fungal sporulation and the HA production as well as the hypothesis of synergistic effect of the polymers. The results demonstrated the feasibility of the HA production by fermentation process, whose description in the literature is still very limited, which confers an innovative character to this work / Doutorado / Desenvolvimento de Processos Biotecnologicos / Doutora em Engenharia Quimica
22

[en] REMOVAL OF HUMIC ACIDS FROM WATERS WITH PURPOSE POTABILITY USING FENTON REAGENT AS PRÉ-OXIDANT IN WATER TREATMENT PROCESSES / [pt] REMOÇÃO DE ÁCIDOS HÚMICOS DE ÁGUAS COM FINS DE POTABILIDADE UTILIZANDO O REAGENTE DE FENTON COMO PRÉ-OXIDANTE EM PROCESSOS DE TRATAMENTO DE ÁGUA

ANA CAROLINA PATTACINI GALDINO 19 April 2017 (has links)
[pt] A água potável é essencial para uma boa qualidade de vida e saúde da população. Nos mananciais, a água naturalmente encontrada possui matéria orgânica e microorganismos, alguns até mesmo patogênicos, sendo necessário o seu tratamento em estações de tratamento de água (ETAs). O cloro é o principal reagente atualmente utilizado como pré-oxidante da matéria orgânica em ETAs, gerando compostos organo-halogenados de características cancerígenas. Neste trabalho foi realizado um estudo do reagente de Fenton como pré-oxidante com o fim de degradar os ácidos húmicos (AH), que são os principais constituintes da matéria orgânica naturalmente encontrada em águas de mananciais, sem a geração dos compostos organo-halogenados. Para isto, foram realizados experimentos de acordo com um planejamento fatorial 23 que investigou a influência de três variáveis na degradação de AH: pH, dosagem de peróxido de hidrogênio e razão molar [H2O2]:[Fe elevado a 2 positivo]. Os resultados obtidos a partir destes experimentos mostraram que todas as variáveis influenciaram na degradação do AH, de forma que o aumento tanto da dosagem de peróxido de hidrogênio quanto da razão molar [H2O2]:[Fe elevado a 2 positivo] gera o aumento na degradação de AH. Com relação ao pH, o aumento desta variável gerou uma ligeira queda na degradação de AH. Assim, a partir de todos os experimentos verificou-se que aquele de melhor resultado apresenta as seguintes condições operacionais: dosagem de peróxido de hidrogênio igual a 42,98 mg/L, [H2O2]:[Fe elevado a 2 positivo] igual 3:1, pH igual a 7. Nestas condições operacionais, após 5 minutos de reação, a redução de AH foi de 95,66 por cento, a redução de COT de 24,94 por cento e a velocidade inicial de degradação de AH de 9,38 mg/L.min. / [en] Drinking water is essential to a good quality of life and health of the populations. In the surface, the water found naturally contains organic matter and microorganisms, some even pathogenic, requiring their removal in water treatment plants (WTPs). Chlorine is the main reagent currently used as pre-oxidant of the organic matter in WTPs, generating chlorinated organic compounds of carcinogenic characteristics. In this project a study of the Fenton reagent as pre-oxidant has been conducted in order to degrade the humic acids (HA), which are the main constituents of the organic matter naturally found in water sources without generating the chlorinated organics. For this, experiments have been conducted according to a factorial design 23 which investigated the influence of three variables in the HA degradation: pH; hydrogen peroxide dosage; and molar ratio [H2O2]:[Fe to the power of 2 positive]. The results obtained from these experiments showed that all variables influence the degradation of HA, so that the increase of the hydrogen peroxide dosage as well as the molar ratio [H2O2]:[Fe to the power of 2 positive] increase HA degradation. With regard to the pH, the increase of this variable generates a slight drop in AH degradation. Thus, from all experiments it has been verified that that the best result were obtained in the following operating conditions: hydrogen peroxide dosage equal 42,98 mg/L, [H2O2]:[Fe to the power of 2 positive] equal 3:1, pH equal 7. Under these operating conditions, after 5 minutes of batch reaction, the reduction of HA was 95,66 percent, the TOC reduction of 24,94 percent and the initial rate of HA degradation of 9,38 mg/L.min.
23

Renovation of wastewater for direct re-use in an abattoir

Roux, Annalie 08 April 2010 (has links)
Tertiary treatment methods were tested on secondary effluent from an abattoir biological wastewater treatment plant with the purpose of renovating it for re-use in the abattoir. The colour and dissolved organic matter could be removed to such an extent that the water would comply with water of insignificant health risk (Department of Health). The treatment process sequence proven to be effective in upgrading this water so insignificant health risk standard were coagulation with a polymer blend, separation, ozonation, filtration and activated carbon filtration. The development of biologically activated carbon in practice was accepted as inevitable and desirable for optimum water quality, but not tested. A deciding factor in the selection of an appropriate treatment was that the final water would also have acceptable corrosion properties. / Dissertation (MSc)--University of Pretoria, 2010. / Chemical Engineering / unrestricted
24

Difúze v huminových gelech s inkorporovanými kovovými ionty / Diffusion in humic gels with incorporated metal ions

Krpatová, Lenka January 2008 (has links)
The main topic of this diploma thesis is the study of diffusion of humic gels with incorporation of copper ions. Humic gel was prepared by precipitation of humate sodium with 5 M copper dichloride. First, it was necessary to find a useful extraction of surfactant that would have extracted copper from humic gel. Magnesium chloride was chosen as optimal surfactant from obtain relation of concentration copper(II) ions on time. Magnesium chloride was used to elution of copper from the slices of the gel. In next part it was important to verify the diffusion method that reaction in gel was not proceed in. Elution from slices of the gel before and after diffusion were scaled on the UV/VIS spectrophotometer. Experiment was prepared for times 3, 12, 24, 48 and 72 hours. Coefficient of the diffusion was calculated from obtained results, but 72 hours was not counted to the result.¨ From the coeficient of diffusion theoretic concentration profiles were calculated and then they were compared with experimentally results. Profile for 72 hours shows that it was unusable because it was oblate and fringe and concentration was lower than in other profiles. Other theoretic profiles agree.
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Vliv fyzikálních podmínek na difúzní procesy v huminových gelech / influence of physical conditions on diffusion processes in humic gels

Marvan, Jan January 2008 (has links)
Diploma thesis is based on diffusion processes of copper (II) ions to humic gels obtained from lignite. Solutions with various concentrations and acidity were exposed to diffusion for exact time 24 hours. After the diffusion was ended the copper (II) ionic concentration profiles of tubular gels were create and calculated total diffusion flux. The experiment showed that the higher acidity of copper (II) solution decrease an amount of immobilized Cu2+ ions to the humic gels. In comparison concentration/pH: concentration of the solution has higher influence on sorption metal ions than change of the pH.
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Stabilita komplexů huminových kyselin s těžkými kovy / Stability of complexes of humic acids with heavy metals

Nováčková, Kristýna January 2011 (has links)
Tato diplomová práce je zaměřena na porovnání termo-oxidační a chemické stability kovových komplexů huminových kyselin. Pro tyto experimenty byly vybrány tři prvky reprezentující skupinu těžkých kovů (kobalt, měď a nikl). Použitá huminová kyselina byla extrahována z Jihomoravského lignitu. Pro přípravu komplexů byly využito různě koncentrovaných roztoků kovů, aby bylo možné pozorovat vliv jejich počáteční koncentrace na obě studované stability připravených komplexů. Chemická stabilita kovových komplexů byla posuzována z hlediska uvolňování kovových iontů ze struktury huminové kyseliny do dvou různých extrakčních činidel (HCl, MgCl2). Termo-oxidační chování bylo zkoumáno pomocí technik termické analýzy: diferenční kompenzační kalorimetrie (DSC) a zejména termogravimetrické analýzy (TGA). Výsledky této práce přinášejí hlubší poznatky o problematice interakce kovů s humifikovanou částí půdní organické hmoty, využitelné k osvětlení problematiky kovových polutantů v životním prostředí a prohloubení žádoucích znalostí procedur jako jsou dekontaminace půdy a remediace.
27

Vliv reaktivity na transport kovových iontů v huminových gelech / Influence of reactivity on transport of metal ions in humic gels

Smitalová, Michaela January 2013 (has links)
This diploma thesis deals with copper(II) ions diffusion in the humic hydrogels. The hydrogels were prepared from several samples of humic acids using different method and their isolation conditions from the original matrix. A selective blocking of functional groups (COOH, OH) was performed in the selected samples of humic acids. These reactive groups were selectively blocked using methylation agent trimethylsilyl-diazomethane. The success of performed methylation and functional groups blocking was verified using a FT-IR spectroscopy. There was carried out the set of diffusion experiments. The experimental arrangement was selected to enable an instantaneous planar source met-hod for data processing. The basis of this method was to determine the copper(II) ions con-centration distribution in the hydrogels. The method consists of slicing of the hydrogels after the diffusion experiments, extraction of the copper ions in the solution and determina-tion of concentration in the extracts from individual slices using UV-VIS spectroscopy. Based on the experimental data the effective diffusion coefficients were determined. The resulting values include both the effect of hydrogels structure and the effect of the reaction between Cu(II) ions and humic acids. There were prepared gels with defined portion of blocked functional groups for selected samples, which allowed to investigate the effect of reactivity on the copper ions diffusion without the significant changes in the gel structure (porosity). The blocking of functional groups reflected in a lower values of diffusion coefficients in comparison to the gels prepared from unmodified humic acids as follows. There was also confirmed the effect of humic acids isolation procedure and their properties on the diffusivity.
28

Lignitové hydrokoloidy / Lignite hydrocolloids

Macháčková, Mirka January 2013 (has links)
This diploma thesis deals with the study of non-energy use of lignite. The main objective was to find an optimal recipe for the preparation of liquid and semi-solid (paste) hydrocolloids from the South Moravian lignite using the planetary mill and select the suitable dispersion medium with emphasis on possible use in agriculture. The used solutions were 10, 20 a 40 % w/w solutions of urea; 5, 10 a 15 % w/w solutions of citric acid; 1, 5 a 10 % w/w solutions of potassium chloride and deionized water. The best weight ratio for the preparation of lignite hydrocolloids is 1 part of lignite and 2 parts of the solution. The next part of this work is the isolation of humic acid from lignite hydrocolloids. The weight of isolated humic acids and amount of ash were compared to the used lignite hydrocolloids. Rheological behavior, particle size distribution, stability and thermal stablity of prepared lignite hydrocolloids were investigated. Correlation microscopy was used for determining elemental composition of selected location in the sample of lignite hydrocolloid.
29

Studium transportu huminových látek skrz rostlinné kutikuly / Study on the transport of humic acids through the plant cuticles

Smilková, Marcela January 2014 (has links)
This diploma thesis is focused on foliar fertilization. It is nowadays one of the most widespread types of application of commercial fertilizers. Concern of this thesis is the study of plant cuticles as a thin layer on the leaves. These thin membranes are responsible for regulation of water transport and nutrients. Further function of plant cuticles is the mechanical protection of the outer part of the plant. Plant cuticles were characterized by fluorescence spectroscopy, classical optical microscopy and profilometry. The main aim of this thesis is the optimization and verification of experimental methodology aimed to the transport of commercial humic product through plant cuticles by simple diffusion techniques. The results obtained by presented diffusion techniques of humic product through plant cuticles were correlated with the same diffusion experiments through synthetic membranes with defined pore size and density. The study on transport of commercial humic product was realized in hydrogel medium by two different diffusion methods – non-stationary diffusion technique and diffusion couple. The important part of this diploma thesis is the characterization of supported hydrogel matrix by rheology tests, mercury intrusion porosimetry and scanned electron microscopy. Conclusions of this diploma thesis could be used for improving of efficiency of foliar fertilization.
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Chemické a fyzikální transformace huminových kyselin / Chemical and Physical Transformations of Humic Acids

Vlčková, Zoja January 2009 (has links)
Tato práce představuje pilotní studii testující souvislosti mezi biologickými vlastnostmi a strukturou huminových kyselin extrahovaných z původního a modifikovaného jihomoravského lignitu, důl Mír, Mikulčice. V první části práce byly testovány metody vhodné ke zvýšení výtěžku huminových kyselin extrahovaných z lignitu. Oxidace lignitu v plynné fázi nepřinesla uspokojivé zvýšení výtěžku a byla instrumentálně poměrně náročná. Dále proto byla zkoumána jen oxidace v kapalné fázi a modifikace nízkomolekulárními organickými kyselinami. Modifikace organickými kyselinami byla inspirována procesy podporujícími biologické funkce v rizosféře, t.j. kořenový systém vylučuje exudáty způsobující změny v supramolekulové struktuře okolní organické hmoty čímž zlepšuje její mobilitu a prostupnost buněčnými stěnami. Primární struktura huminových kyselin připravených v této práci byla zkoumána prostřednictvím elementární analýzy a spektrálních metod (13C CPMAS NMR, EPR a UV-VIS spektroskopie). Navzdory tomu, že primární struktura vykazovala jen malé rozdíly, měření biologické aktivity a genotoxického potenciálu prokázalo, že huminové kyseliny a jejich humáty získané z lignitu s rozdílnou předúpravou vykazují odlišnou bioaktivitu. Proto byla dále zkoumána supramolekulární struktura vzorků ve zředěných roztocích, a to prostřednictvím vysokoúčinné vylučovací chromatografie, měření ultrazvukové rychlosti a hustoty. Testovány byly dva různé protionty – draselný a amonný. Získané výsledky potvrdily předpoklad, že pozorované změny v kvalitě humátů jsou závislé na protiiontu, koncentraci humátu v roztoku a také na metodě předúpravy původního lignitu. Obě zvolené metody předúpravy lignitu prokázaly svůj potenciál produkovat huminové kyseliny s rozmanitými biologickými vlastnostmi, aplikovatelné v zemědělství, životním prostředí a potenciálně i ve farmakologii.

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