<p>Two species of emergent macrophytes, Typha latifolia (common cattail) and Phalaris arundinacea (reed canary grass) were evaluated as substrates for biogas production. The specific methane yield for each plant was obtained by batch wise anaerobic digestion in 300-mL bottles. Three different pretreatments were evaluated for increased biogas production; mechanical milling, alkaline treatment with lime and fungal degradation with Pleurotus ostreatus (oyseter mushroom).The methane yield for Typha latifolia and Phalaris arundinacea was determined to 300 and 323mL methane per g VS, respectively. There was no statistical difference in methane yield between the two species. Milling pretreatment increased the biogas yield with 16 % by average compared to untreated plant. Alkaline pretreatment with lime increased the biogas yield with 27 % at roomtemp. and 22 % at 55 °C. The fungal pretreatment decreased the biogas production by 20 % and is probably not suitable for this kind of substrate.The results showed that emergent macrophytes have a biogas yield similar to other plants already tested (grasses) and commonly used (pasture crops) in large scale reactors. However, emergent macrophytes and grasses cause mechanical problems in a reactor due to their structure. Probably some kind of milling must be done to decrease the fiber length of the emergent macrophytes. The costs for harvest, transport, handling and possible pretreatment of the emergent macrophytes have to be estimated and included in the overall cost calculations. This can tell if emergent macrophytes should be used as a substrate for biogas production.</p>

Global warming along with energy demand and rising prices of natural energy resources have motivated studies to find some renewable and clean energy. The use of algae as third generation biofuel can avoid the competition for farmland and algae can be considered as a potential future source of renewable energy. Algae can be used for biogas production through anaerobic digestion (AD). Fucus vesiculosus and Fucus serratus are the two dominating species of brown seaweed growing in the Baltic sea in the southwest of Sweden. Pretreatment can significantly affect the biogas production since hydrolysis of algae cell wall structure is a rate-limiting step in AD process. In this study, four different pretreatments: mechanical, microwave (600W, 2min), ultrasonic (110V, 15min), and microwave combined with ultrasonic (600W, 2min;110V, 15min) were applied to the seaweed and then co-digested with biogas plant leachate. The aim was to investigate the biogas production and methane yield from AD after these pretreatments. The results showed when comparing with mechanical pretreated only, that the ultrasonic, ultrasonic combined with microwave and microwave pretreatments could obtain increased cumulative methane yields with 167%, 185% and 156% , respectively. The maximum methane yield was 260 ml/g∙VS with combined pretreatment after 20 days of digestion. The ultrasonic combined with microwave pretreatment showed a significant improvement of methane yield when comparing with mechanical pretreatment.

Resumo: Neste trabalho estudou-se a influência de pré-tratamentos químicos, com emulsões a base de óleo e lecitina de soja e carbonato de potássio, sobre a cinética de secagem da uva Rubi. A secagem foi conduzida em um secador de leito fixo, à temperatura fixa de 60ºC, velocidade de ar de 0,9 m/s e umidade relativa do ar de secagem do ambiente na faixa de 18 a 20 %. A umidade inicial das amostras de uva Rubi variou entre 81 a 84% (base seca) e o conteúdo de sólidos solúveis ficou em torno de 11o Brix. O objetivo deste trabalho foi estudar um pré-tratamento alternativo a base de lecitina e óleo de soja na cinética de secagem da uva Rubi, otimizando as concentrações dessas substâncias de modo a minimizar o tempo de secagem. Foram calculados os coeficientes de difusividade aparente a partir do ajuste dos dados experimentais de secagem pela solução analítica da 2a Lei de Fick para uma esfera. A desconsideração do encolhimento da fruta levou ao péssimo ajuste dos dados pela 2a Lei de Fick. As curvas de secagem foram ajustadas pelo modelo de Page. A avaliação deste modelo foi feita pelo cálculo do R2 (> 0,99) e do RMS (< 30%). Este ajuste representou satisfatoriamente os dados experimentais às curvas. A cinética de secagem foi avaliada pela análise estatística dos efeitos das condições do pré-tratamento químico - tempo de imersão da uva e concentração de lecitina, carbonato de potássio e óleo de soja nas emulsões - sobre o parâmetro K do modelo de Page. Observou-se que o tempo de imersão e suas interações com as concentrações dos componentes em estudo não foram significativos no nível de 5%. Quando todos os componentes são empregados nas máximas e mínimas concentrações testadas, mesmo para o mínimo tempo de imersão (3 minutos), há um aumento no valor do parâmetro K, o qual está diretamente ligado... Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The influence of pretreatments of emulsions of lecithin, soya oil and potassium carbonate on drying kinetic of grape Rubi was studied in this work. The drying was carried out in a fixed bed dryer, at 60ºC, air velocity of 0,9 m/s and relative humidity of drying air in range from 18 to 20%. The initial moisture varied from 81 to 84% and soluble solids content was 11º Brix. The objective was to study an alternative pretreatment with lecithin, soya oil and potassium carbonate, optimizing the concentration of these substances with the aim of decrease the drying time. The apparent diffusion coefficients were calculated by the adjustment of the experimental data of drying by the analytical solution of the second Fick's Law for a spherical geometry. The fruit shrinkage wasn't taken in consideration. These carried out the bad adjustment of data by the second Fick's Law. The drying curves were adjustment by Page's model. The evaluation was goodness fit was shown through the analysis of the coefficient of determination (R2 > 0,99) and RMS (< 30%). This adjustment was good. The drying kinetics was valued through the statistical analysis of chemical pretreatment effects - dipping time of grape and concentration of lecithin, potassium carbonate and soya oil - on the parameter k of Page's model. It was checked that dipping time and their interactions with the concentrations of the components in study were not significant in the level of 5%. When all components are spent in maximum and minimum concentration tested, even for the minimum dipping time (3 minutes), there is an increase in value of parameter K, which is straight into to the drying rate and reduction of drying time. The equilibrium moisture used in the calculation of adimensional for drying curves was obtained by isotherms data of Rubi grape without... (Complete abstract click electronic access below) / Orientador: Javier Telis Romero / Coorientador: Vânia Regina Nicoletti Telis / Banca: José Roberto Dalalíbera Finzer / Banca: José Antônio Gomes Vieira / Mestre

Doctor of Philosophy / Department of Civil Engineering / Kyle A. Riding / The cement industry is an important component in the quest to reduce global greenhouse gas emissions because of vast amounts of cement used annually. Incorporating supplementary cementitious materials (SCMs) into concrete is one alternative to reduce cement production and thereby reduce greenhouse gas emissions. This study investigated three types of agricultural residues, namely corn stover, wheat straw, and rice straw, in addition to bioethanol byproducts as potential resources for SCM production for concrete applications. Pretreatments, commonly used in bioethanol production, were used to improve pozzolanic reactivity of corn stover ash (CSA), wheat straw ash (WSA), and rice straw ash (RSA) in cementitious systems. In the first part of this research, the impact of distilled water and dilute hydrochloric acid pretreatments on pozzolanic reactivity of WSA, RSA, and CSA were studied. Results showed that pretreatments, particularly dilute acid, improved pozzolanic properties of CSA, WSA, and RSA by removing potassium and phosphorous from the biomass prior to ashing. In addition, WSA and RSA were shown to have similar pozzolanic reactivity to that of silica fume. In the second part of this study, suitability of high lignin residue (HLR), a bioethanol byproduct, for SCM production was investigated. It was shown that burning high lignin residue produces HLR ash that is very reactive in cementitious materials and can be used as a reactive SCM in concrete. The impact of each step in the production of bioethanol on the quality of bioethanol byproduct for subsequent burning and use in concrete was also studied. Sodium hydroxide and sulfuric acid pretreatments and enzymatic hydrolysis were used. Results revealed that sodium hydroxide pretreatment of the biomass have negative impact on biomass ash properties for concrete use because sodium hydroxide pretreatment did not remove phosphorous and other crystalline phases out of the biomass. However, sulfuric acid pretreatment of biomass greatly improved ash properties. It was also shown that enzymatic hydrolysis could have beneficial impact on ash properties because, during enzymatic hydrolysis, some phosphorous was leached out of the biomass.

Anaerobic digestion is a sustainable and economically feasible waste management technology, which lowers the emission of greenhouse gases (GHGs), decreases the soil and water pollution, and reduces the dependence on fossil fuels. The present thesis investigates the anaerobic digestion of waste from food-processing industries, including citrus wastes (CWs) from juice processing and chicken feather from poultry slaughterhouses. Juice processing industries generate 15–25 million tons of citrus wastes every year. Utilization of CWs is not yet resolved, since drying or incineration processes are costly, due to the high moisture content; and biological processes are hindered by its peel oil content, primarily the D-limonene. Anaerobic digestion of untreated CWs consequently results in process failure because of the inhibiting effect of the produced and accumulated VFAs. The current thesis involves the development of a steam explosion pretreatment step. The methane yield increased by 426 % to 0.537 Nm3/kg VS by employing the steam explosion treatment at 150 °C for 20 min, which opened up the compact structure of the CWs and removed 94 % of the D-limonene. The developed process enables a production of 104 m3 methane and 8.4 L limonene from one ton of fresh CWs. Poultry slaughterhouses generate a significant amount of feather every year. Feathers are basically composed of keratin, an extremely strong and resistible structural protein. Methane yield from feather is low, around 0.18 Nm3/kg VS, which corresponds to only one third of the theoretical yield. In the present study, chemical, enzymatic and biological pretreatment methods were investigated to improve the biogas yield of feather waste. Chemical pretreatment with Ca(OH)2 under relatively mild conditions (0.1 g Ca(OH)2/g TSfeather, 100 °C, 30 min) improved the methane yield to 0.40 Nm3/kg VS, corresponding to 80 % of the theoretical yield. However, prior to digestion, the calcium needs to be removed. Enzymatic pretreatment with an alkaline endopeptidase, Savinase®, also increased the methane yield up to 0.40 Nm3/kg VS. Direct enzyme addition to the digester was tested and proved successful, making this process economically more feasible, since no additional pretreatment step is needed. For biological pretreatment, a recombinant Bacillus megaterium strain holding a high keratinase activity was developed. The new strain was able to degrade the feather keratin which resulted in an increase in the methane yield by 122 % during the following anaerobic digestion. / <p>Akademisk avhandling som för avläggande av teknologie doktorsexamen vid Chalmers tekniska högskola försvaras vid offentlig disputation den 1 juni 2012, klockan 10.00 i KA-salen, Kemigården 4, Göteborg.</p>

Neste trabalho, foram utilizadas metodologias ópticas para estudo da interação enzimática e de pré-tratamentos da biomassa. Mudanças de carga em fibras de polpa de eucalipto foram estudadas utilizando-se uma porfirina como sonda, uma vez que influenciam na interação enzimática. Foi investigada também a influência do caráter de carga na interação com a safranina, utilizada como marcador de celulose. Estudamos o efeito do pH na interação da enzima Celobiohidrolase Cel7A (CBH I) e de seus domínios separadamente com as fibras de eucalipto por meio do método de arraste, que se baseia na centrifugação da solução dos interagentes e na análise espectroscópica do sobrenadante. Essa interação também foi estudada por microscopia de fluorescência confocal utilizando-se fluoresceína como marcador para as enzimas. Outro objetivo do trabalho foi aplicar a microscopia confocal e a microscopia de imagem de tempo de vida da fluorescência (FLIM),com excitação por um e por dois fótons, para estudar a atuação de um pré-tratamento em bagaço de cana-de-açúcar. Esse pré-tratamento teve duas etapas: a primeira com ácido e a segunda com base.Os resultados para a interação da CBH I com as fibras de eucalipto mostram que esta é influenciada por mudanças de carga tanto no módulo de ligação à celulose (CBM) quanto no domínio catalítico. Imagens espectrais de microscopia confocal indicam a presença da enzima em interstícios ao longo de toda a parede da fibra. Nas amostras de bagaço, há uma forte correlação entre os tempos de decaimento da fluorescência da lignina e sua concentração. Uma não homogeneidade nas características de fluorescência ao longo da parede celular revela domínios de níveis distintos de agregação da lignina. O pré-tratamento ácido desordena a lignina e a acumula na borda externa da parede celular. O pré-tratamento alcalino remove eficientemente a lignina do centro da parede celular, mas não é tão eficiente próximo à superfície. Uma variedade complementar de estados foi acessada pela excitação por dois fótons. Uma estreita banda de emissão e tempos longos de decaimento sugerem que no bagaço não tratado a lignina é organizada de maneira que haja uma fraca interação entre as moléculas. / Optical methodologies were used for the study of the enzymatic interaction and pretreatments of biomass. Changes of charge on eucalyptus pulp fibers were studied with the use of a porphyrin as a probe, since these changes influence on the enzymatic interaction. The influence of the charge character was also investigated for the interaction with safranin, used as cellulose labeling. We studied the pH effect on the interaction of the enzyme Cellobiohydrolase Cel7A (CBH I) and its domains separately with eucalyptus pulp fibers by the drag method, which is based on the centrifugation of the enzymes solution with the fibers and on the spectroscopic analysis of the supernatant. This interaction was also studied by confocal fluorescence microscopy with the use of fluorescein as a labeling for the enzymes. Another objective was the application of confocal microscopy and fluorescence lifetime imaging microscopy (FLIM), both with single-photon and two-photon excitation, in the study of a pretreatment applied in sugarcane bagasse. This pretreatment had two steps: the first one with acid and the second one with alkali. The results for the interaction between CBH I and the eucalyptus fibers show that it is influenced by changes of charge both in cellulose-binding module (CBM) and in the catalytic domain. Spectral confocal images indicate the presence of enzymes along all the cell wall. Regarding the bagasse fibers, a strong correlation was observed between the fluorescence decay time and the delignification. A non-homogeneity of the fluorescence properties along the cell wall reveal domains of lignin with different aggregation levels. The acid pretreatment disorders lignin and accumulate it on the external border of the cell wall. The alkali pretreatment removes lignin from the center of the cell wall efficiently, but it is not so effective close to the surface. A complementary variety of states was accessed by two-photon excitation. A narrow emission band and slow decay times suggest that lignin is organized in such a way that the interaction between the molecules is weak.

Two species of emergent macrophytes, Typha latifolia (common cattail) and Phalaris arundinacea (reed canary grass) were evaluated as substrates for biogas production. The specific methane yield for each plant was obtained by batch wise anaerobic digestion in 300-mL bottles. Three different pretreatments were evaluated for increased biogas production; mechanical milling, alkaline treatment with lime and fungal degradation with Pleurotus ostreatus (oyseter mushroom).The methane yield for Typha latifolia and Phalaris arundinacea was determined to 300 and 323mL methane per g VS, respectively. There was no statistical difference in methane yield between the two species. Milling pretreatment increased the biogas yield with 16 % by average compared to untreated plant. Alkaline pretreatment with lime increased the biogas yield with 27 % at roomtemp. and 22 % at 55 °C. The fungal pretreatment decreased the biogas production by 20 % and is probably not suitable for this kind of substrate.The results showed that emergent macrophytes have a biogas yield similar to other plants already tested (grasses) and commonly used (pasture crops) in large scale reactors. However, emergent macrophytes and grasses cause mechanical problems in a reactor due to their structure. Probably some kind of milling must be done to decrease the fiber length of the emergent macrophytes. The costs for harvest, transport, handling and possible pretreatment of the emergent macrophytes have to be estimated and included in the overall cost calculations. This can tell if emergent macrophytes should be used as a substrate for biogas production.

Campylobacter is considered a fragile microorganism ans sensitive to environmental conditions, but demostrate strategies to survive in unfavorable environmental conditions. This study evaluated the viability and production of transcipts of the genes sodB, p19 ciaB and dnaJ in strains ATCC 33291, NCTC 11351 and IAL 2383 stored in UHT milk and neopeptona + 12% glycerol,whether or not subject to the pre-treatment temperature of 4°C or 10°C for 30 minutes.Analyses were performed immediately after freezing in liquid nitrogen (day 0) and after maintenance for 30, 60 and 90 days at -20°C.The viability was evaluated by traditional method of cultivation and production of transcripts by RT-PCR technique. The quantification was only possible on the first day of analysis (day 0) and had a mean of 3.0x107UFC and in the remaining periods of storage strains showed confluent growth not allowing their enumeration. The set of results has shown that the UHT milk was the most appropriate for cryopreservation than the use of neopeptona +12% glycerol. The pretreatment at 4°C for 30 minutes favored the production of transcripts for ciaB and dnaJ genes. For the strains ATCC 33291 and NCTC 11351 was verified a possible interconnection of sodB genes and p19, however, this link was not observed for the strain IAL 2383, which also showed different behavior from other strains for viability in both cryoprotectants and production of transcripts. The results of this study show that when the maintenance of viability of the strains is essential, it is necessary to use different combinations of cryoprotectants / treatments to increase the chances of recovery and, when the primary purpose is the production of transcripts, the option to maintain the reliability of the results is the immediate extraction of DNA of isolated strains. / Campylobacter é considerado um microrganismo frágil e sensível às condições ambientais, mas que demonstram possuir estratégias para sobreviver em condições ambientais desfavoráveis. Este estudo avaliou a viabilidade e produção de transcritos dos genes sodB, p19, ciaB e dnaJ em cepas ATCC 33291, NCTC 11351 e IAL 2383 armazenadas em leite UHT integral e neopeptona + glicerol 12%, submetidas ou não a pré-tratamentos à temperatura de 4°C ou 10°C por 30 minutos. As análises foram realizadas imediatamente após o congelamento em nitrogênio líquido (dia 0) e após manutenção por 30, 60 e 90 dias a -20ºC. A viabilidade foi avaliada pelo método tradicional de cultivo e a produção de transcritos pela técnica do RTPCR. A quantificação só foi possível no primeiro dia de análise (dia 0) e apresentaram média de 3,0 x 107 UFC, sendo que nos demais períodos de armazenamento as cepas apresentaram crescimento confluente não permitindo sua enumeração. O conjunto de resultados permitiu verificar que o leite UHT integral foi mais adequado para a criopreservação que o uso da neopeptona + glicerol 12%. O pré-tratamento a 4ºC por 30 minutos favoreceu a produção de transcritos para os genes ciaB e dnaJ. Para as cepas ATCC 33291 e NCTC 11351 foi verificada uma possível interligação dos genes sodB e p19, entretanto, esta ligação não foi observada para a cepa IAL 2383, que também mostrou comportamento diferente das outras cepas quanto à viabilidade nos dois crioprotetores e produção de transcritos. Os resultados obtidos neste estudo permitem concluir que quando a manutenção da viabilidade das cepas é essencial, faz-se necessário o uso das diferentes combinações crioprotetor/tratamentos para aumentar as chances de recuperação e, quando o objetivo principal é a produção de transcritos, a opção para manter a fidedignidade dos resultados é a extração imediata do DNA das estirpes isoladas. / Mestre em Ciências Veterinárias

Neste trabalho, foram utilizadas metodologias ópticas para estudo da interação enzimática e de pré-tratamentos da biomassa. Mudanças de carga em fibras de polpa de eucalipto foram estudadas utilizando-se uma porfirina como sonda, uma vez que influenciam na interação enzimática. Foi investigada também a influência do caráter de carga na interação com a safranina, utilizada como marcador de celulose. Estudamos o efeito do pH na interação da enzima Celobiohidrolase Cel7A (CBH I) e de seus domínios separadamente com as fibras de eucalipto por meio do método de arraste, que se baseia na centrifugação da solução dos interagentes e na análise espectroscópica do sobrenadante. Essa interação também foi estudada por microscopia de fluorescência confocal utilizando-se fluoresceína como marcador para as enzimas. Outro objetivo do trabalho foi aplicar a microscopia confocal e a microscopia de imagem de tempo de vida da fluorescência (FLIM),com excitação por um e por dois fótons, para estudar a atuação de um pré-tratamento em bagaço de cana-de-açúcar. Esse pré-tratamento teve duas etapas: a primeira com ácido e a segunda com base.Os resultados para a interação da CBH I com as fibras de eucalipto mostram que esta é influenciada por mudanças de carga tanto no módulo de ligação à celulose (CBM) quanto no domínio catalítico. Imagens espectrais de microscopia confocal indicam a presença da enzima em interstícios ao longo de toda a parede da fibra. Nas amostras de bagaço, há uma forte correlação entre os tempos de decaimento da fluorescência da lignina e sua concentração. Uma não homogeneidade nas características de fluorescência ao longo da parede celular revela domínios de níveis distintos de agregação da lignina. O pré-tratamento ácido desordena a lignina e a acumula na borda externa da parede celular. O pré-tratamento alcalino remove eficientemente a lignina do centro da parede celular, mas não é tão eficiente próximo à superfície. Uma variedade complementar de estados foi acessada pela excitação por dois fótons. Uma estreita banda de emissão e tempos longos de decaimento sugerem que no bagaço não tratado a lignina é organizada de maneira que haja uma fraca interação entre as moléculas. / Optical methodologies were used for the study of the enzymatic interaction and pretreatments of biomass. Changes of charge on eucalyptus pulp fibers were studied with the use of a porphyrin as a probe, since these changes influence on the enzymatic interaction. The influence of the charge character was also investigated for the interaction with safranin, used as cellulose labeling. We studied the pH effect on the interaction of the enzyme Cellobiohydrolase Cel7A (CBH I) and its domains separately with eucalyptus pulp fibers by the drag method, which is based on the centrifugation of the enzymes solution with the fibers and on the spectroscopic analysis of the supernatant. This interaction was also studied by confocal fluorescence microscopy with the use of fluorescein as a labeling for the enzymes. Another objective was the application of confocal microscopy and fluorescence lifetime imaging microscopy (FLIM), both with single-photon and two-photon excitation, in the study of a pretreatment applied in sugarcane bagasse. This pretreatment had two steps: the first one with acid and the second one with alkali. The results for the interaction between CBH I and the eucalyptus fibers show that it is influenced by changes of charge both in cellulose-binding module (CBM) and in the catalytic domain. Spectral confocal images indicate the presence of enzymes along all the cell wall. Regarding the bagasse fibers, a strong correlation was observed between the fluorescence decay time and the delignification. A non-homogeneity of the fluorescence properties along the cell wall reveal domains of lignin with different aggregation levels. The acid pretreatment disorders lignin and accumulate it on the external border of the cell wall. The alkali pretreatment removes lignin from the center of the cell wall efficiently, but it is not so effective close to the surface. A complementary variety of states was accessed by two-photon excitation. A narrow emission band and slow decay times suggest that lignin is organized in such a way that the interaction between the molecules is weak.

Screen printed electrodes (SPEs), which are prepared by patterning conductive inks or pastes onto an insulating support (e.g., plastic film), are widely employed as sensing and biosensing platforms due to their ease of fabrication and relatively low cost. This is especially applicable to electrodes of this nature prepared with carbon-based inks (SPCEs). To date, the most successful and significant commercial application of SPEs has been as test strips for glucose meters. Despite the maturity of this technology, SPE research remains very active as improvements in sensitivity and selectivity, which often involve modifying the electrode surface, hold the key to advancing their utility in routine applications and extending their benefits to other target analytes. Recent studies in the Bishop research group have demonstrated that nitrogen-doped SPCEs (N-SPCEs) exhibit enhanced electrochemical response towards hydrogen peroxide (H2O2), a product of oxidase enzyme (e.g., glucose oxidase, lactate oxidase, etc.) reactions and a common target in biosensing strategies. The presence of nitrogen heteroatoms on the carbon surface facilitates breakage of oxygen-oxygen bonds, a key step in reduction of H2O2. Since previous studies showed only modest incorporation of nitrogen species on SPCEs prepared from commercial ink, these studies aim to investigate the possibility of enhancing N-doping by performing a simple pre-treatment strategy that reportedly increases surface oxygen content of SPCEs prior to N-doping. Since surface oxygen sites have been previously reported to be preferentially modified with nitrogen during N doping strategies, this seems like a promising technique for improving sensitivity of N-SPCEs for H2O2 reduction. To quantify the actuality of these claims, experimental groups were fabricated having undergone no enhancement, pretreatment enhancement only, nitrogen-doping enhancement only, and a combination of the pretreatment and nitrogen-doping enhancements. Here the electrochemical behaviors of pretreated SPCEs, N-SPCEs, and pretreated N-SPCEs for the detection of H2O2 by completing comparative cyclic voltammetry (CV) experiments with and without the presence of H2O2 and with it present in varying concentrations is compared. It is projected that, if successful, the fabricated electrodes that have undergone both the pretreatment protocol and the nitrogen-doping process will have an increased sensitivity and detection limit towards H2O2.