The threats of global warming attributed to fossil fuel combustion, combined with increasing energy demands and a growing population, have generated interests in diversifying the world energy mix. Biofuels from microalgae offer a sustainable renewable option and do not suffer the sustainability issues associated with early forms of bioenergy. However, research efforts of nearly 5 decades have not resulted in any significant gains and have motivated further investigation into novel techniques. The dilute nature of microalgae suspensions often requires dewatering and drying, which adds to energy intensity and costs associated with recovery processes. Curiously, the conventional recovery techniques do not consider the characteristic tendency of microalgae cells for surface attachment. This behaviour of cells, coupled with the discovery of a non-porous adsorbent material, NyexTM particles, has brought to the fore an exciting prospect. This has motivated the underpinning question behind this research; does the non-porous characteristic of the NyexTM particles presents an opportunity to recover microalgae cells from suspension using an adsorption technique?Using Chlamydomonas reinhardtii as a model microalgae strain, preliminary batch studies revealed a rapid recovery of the cells onto the NyexTM particles; nearly 90% recovery was attained within one minute, which depends on suspension concentration. At a correlation coefficient, R2 = 0.99, the Freundlich isotherm was found to give a better description of batch systems than the Langmuir isotherm, which suggests that cell coverage onto the NyexTM particles may not be a simple monolayer adsorption. Although a low adsorptive capacity of 0.55 mg/g was measured, the equilibrium parameter (1⁄) of about 0.6 was well within the range for favourable adsorption (i.e. 0 - 1). Further studies undertaken suggest that the recovery of cells could be driven by a hydrophobic-hydrophobic interaction, electrostatic forces of attraction and the flocculating behaviour of the NyexTM particles. Fixed bed studies showed that the lack of pores led to an early breakthrough. However, findings demonstrated that unlike most column studies, the bed capacity was a more valuable parameter to assess the column performance. Unexpectedly, depressed breakthrough curves, where bed exhaustion never attained Ct/C0 = 1.0, were observed. Nonetheless, the modified dose response (MDR) model was found to predict the experimental bed capacity to a greater degree of accuracy than other models. Furthermore, this research exploited the logistic features of the Bohart-Adams and the Clark models to adapt them to the experimental data. The adapted models significantly improved the accuracy of predictions with R2 values > 0.99 for the depressed breakthrough curves. The conductive nature of NyexTM particles was explored to electrochemically regenerate the adsorbent and reuse it to recover more cells. A current density of 32 mA.cm-2 was sufficient to inactivate the cells, regenerate the adsorbent and attain a maximum percentage recovery. Interestingly, scanning electron micrograph showed that the membranes of the adsorbed cells were ruptured, during NyexTM regeneration, potentially leading to lipid release. The maximum lipids extracted into a hexane solvent was estimated as 30 μg/mL at a current density of 64 mA.cm-2.Overall, the potential to recover microalgae cells onto a non-porous adsorbent has been demonstrated. The prospect of rupturing membranes of adsorbed cells offers the opportunity to use this technique to recover microalgae cells for potential biofuel applications. The results obtained from this research can serve as the impetus to further exploit this novel procedure. Future work should consider high lipid producing varieties of microalgae strains, develop a robust protocol to account for all forms of lipids released and undertake an energy and cost analysis to develop the technology further.

Pharmaceuticals and personal care products found in the environment pose a significant hazard to human and ecosystem health. While there has been significant work on the fate and remediation of pharmaceuticals and personal care products in wastewater treatment, relatively little work has explored the fate, transport and remediation of these compounds in non-point source input. This is concerning given the increasing use of pharmaceuticals in livestock production and wastewater treatment derived biosolids frequently applied to land. These experiments aimed to quantify the abiotic adsorption and biotic transformation and uptake potential of woodchips and biochar-amended woodchips as a potential sorbent strategy for diffuse acetaminophen (ACT) pollution. Batch reactions were created in triplicate, supplied with 5 mM ACT, and analyzed over an eight hr period using ultraviolet spectrophotometry (298 nm). Ultraviolet absorbance readings for each time step then were compared to standard curves and solution ACT concentration was determined. Decreases in ACT from initial concentrations were the result of either abiotic and/or biotic. Overall, the woodchips and biochar-amended woodchips showed similar removal efficiency (16-21% of initial concentration). Whole model ANOVA analysis showed biologic activity having no significant effect on ACT solution concentration. However, within group ANOVA comparison showed significant differences between abiotic and biotic WC and abiotic and biotic WC treatments (controlling for media). Thus, the media effect could have masked the effect of biology on ACT removal. Species capable of degrading ACT exist and further study into their ability to grow and survive on these sorbents requires further work. / Master of Science

Foi realizado um experimento no aviário experimental do Departamento de Zootecnia da Universidade de São Paulo (USP), na Faculdade de Zootecnia e Engenharia de Alimentos (FZEA), em Pirassununga/SP com o objetivo de avaliar o efeito de dois níveis vitamínicos (comercial e OVN) com ou sem aflatoxina em dietas de frangos de corte no período de 1 a 42 dias. Foram utilizados 1800 pintinhos, machos, Cobb 500, distribuídos em um delineamento inteiramente casualizado em esquema fatorial 2 x 2 x 2 (2 níveis vitamínicos - comercial e OVN, 2 níveis de aflatoxina - 0 ppm e 0,5 ppm, e 2 níveis de adsorventes - 0 e 10 kg/ton), totalizando 8 tratamentos com 15 repetições de 15 aves cada. As dietas foram fornecidas fareladas e a base de milho e farelo de soja, formuladas segundo os níveis praticados por uma integradora da região. Para avaliar o desempenho foram analisados o consumo de ração, ganho de peso e conversão alimentar de 1 a 49 dias. Para avaliação de carcaça (rendimento de carcaça, peito e pernas), determinação de incidência de BBS e determinação do peso das vísceras abdominais e coração foram abatidas duas aves por repetição aos 45 dias. Os resultados mostraram que frangos de corte, machos, alimentados com nível OVN de vitaminas, apresentaram melhor ganho de peso, conversão alimentar, rendimento de carcaça e peito quando comparado com o nível comercial de vitaminas (P<0,05) e que as dietas contendo 0,5 ppm de aflatoxinas resultaram em menor ganho de peso, rendimento de carcaça, porcentagem de peito e aumentou o tamanho do coração e fígado do animal (P<0,05). O uso de 10kg/ton de adsorvente só apresentou resultado positivo no final da vida dos animais (dos 39 a 49 dias) (P<0,05) e somente na conversão alimentar. Esse estudo permite concluir que a aflatoxina resulta em perdas de desempenho e rendimento de carcaças e que o fornecimento de níveis ótimos de vitaminas melhora os resultados dessas características. O uso de adsorventes se mostrou inviável nesse estudo. / An experiment was conducted in an experimental aviary the Department of Animal Science, University of São Paulo (USP), the Faculty of Animal Science and Food Engineering (FZEA) in Pirassununga/SP, to evaluate the performance, carcass characteristics and weight of offal in broiler chickens fed with two levels of vitamins (commercial and VNO) with or without aflatoxin in broiler diets. Were used 1800 chicks, male, Cobb 500 distributed in a completely randomized 2 x 2 x 2 factorial arrangement (two vitamin levels, two levels of aflatoxin and two levels of adsorbents), totaling eight treatments with 15 replicates of 15 birds each. Diets were fed mash and corn and soybean meal, formulated according to the levels charged by an integrator in the region. To evaluate the performance were analyzed feed intake, weight gain, feed conversion from 1 to 49 days. For evaluation of carcass yield (carcass, breast and legs), determination of the incidence of BBS and determination of the weight of the abdominal viscera and heart were killed two birds per replicate at 45 days. The results showed that broilers, males fed VNO level of vitamins showed better weight gain, feed conversion, carcass yield and breast when compared to the commercial level of vitamins (P<0.05) and that diets intoxicated with 0.5 ppm of aflatoxin resulted in less weight gain, carcass yield, percentage of breast and increased the size of the heart and liver of the animal (P<0.05). The use of adsorbent 10kg/ton only had a positive result at the end of life of animals (from 39 to 49 days) (P<0.05) and only in the feed. This study indicates that aflatoxin results in loss of performance and carcass yield and the provision of optimal levels of vitamins improved the results of these characteristics. The use of adsorbents in this study proved to be unfeasible.

Nanostructured molybdenum trioxide (MoO3) was synthesized and used as a precursor in a comparative study, along with commercial MoO3, to synthesize molybdenum dioxide (MoO2) nanoparticles. Scanning electron microscope (SEM) images revealed the particles to be approximately 30-50 nm in diameter. X-ray diffraction (XRD) confirmed MoO3 was fully reduced to MoO2 in all cases. Time dependent experiments showed that within two hours no traces of MoO3 are present. All of the experiments showed the materials were excellent absorbent materials, as well as photocatalysts. Both MoO2 materials performed almost exactly the same, with both samples being able to remove 100% of the methylene blue (MB) in one minute with light, and in two minutes without light. The morphology of MoO2 was controlled in a comparative study by varying the concentration of cetyltrimethylammonium bromide (CTAB) present during the hydrothermal reaction. As the concentration of CTAB increased, the morphology of the material changed from nanoparticles, to nanospheres, to microspheres, to hollow microspheres, and finally a highly agglomerated version of microspheres and particles combined, as confirmed by SEM images. A formation mechanism for the formation of the various sized spheres was proposed with a combination of aggregation and Ostwald ripening. XRD confirmed that all of the MoO3 was reduced to MoO2, along with no residual peaks from the CTAB that was present during the reaction. Upon trying to mix some of the materials into the MB solutions, it became obvious that some of the materials were hydrophobic. The decontamination results once again showed that the synthesized MoO2 materials were not only photocatalysts, but adsorbents as well. Samples synthesized with 0.1-5 mM CTAB were able to remove 100% of the MB in 10 minutes or less. Samples synthesized with 10 mM CTAB were able to remove 54.4% and 35% of the MB in 10 minutes, with and without light, respectively. Samples synthesized with 15 mM CTAB were able to remove 29.4% and 26.3% of the MB in 10 minutes, with and without light, respectively. The apparent decrease in decontamination performance was proposed to be caused by surface morphology induced hydrophobicity. A mechanism to describe why the hydrophobic particles were still able to decontaminate the water was proposed to be caused by coming into direct contact with the magnetic stirrer as the water level dropped due to sample collection. MoO2 nanoparticles were successfully synthesized onto a copper substrate, in a single step, via a hydrothermal synthesis technique. It is believed to be the first report of such a synthesis method. XRD confirmed all of the MoO3 had been reduced to MoO2, and also confirmed that no other compounds had formed between the molybdenum and copper. SEM images of the MoO2 coated copper substrate showed uniform nanoparticles ranging from 30-50 nm. The MoO2 coated copper substrate was able to decontaminate 57.5% of the MB from water in 10 minutes without exposure to light, while it was able to decontaminate 71.7% of the MB from water in 10 minutes with exposure to light.

This study was to investigate the reaction behavior of laboratory-prepared nanoscale adsorbents (Fe3O4 and H-[Fe3O4]MgO) and inorganic pollutants (NO3-, Cd2+and Cr6+) in simulated groundwater. First, Fe3O4 and the composites of nanoscale Fe3O4 and MgO were prepared using chemical co-precipitation method. Then they were characterized and verified by various apparatuses and methods including X-ray diffractometry, scanning electron microscopy, Zetasizer, and specific surface area measurements. Second, the nanoscale adsorbents were used to adsorb inorganic pollutants in simulated groundwater of different conditions. The relevant reaction behavior and mechanisms were also investigated. Results of this research showed that Fe3O4 and H-[Fe3O4]MgO had the greater adsorption amount when the initial concentration of inorganic pollutants was higher than lower. The adsorption rate of inorganic pollutants at 28¢J was greater than that of at 18¢J. The experimental results also showed that at a higher pH environment or the existence of humic acid in simulated groundwater would increase the removal efficiency of Cd2+, but decrease the removal efficiency of NO3- and Cr6+. Analysis of inorganic pollutants adsorption on nanoscale adsorbents in simulated groundwater indicated that a Langmuir-type of chemical adsorption and pseudo-second-order reaction kinetic equation would have better fit. In this study, it was also found that nanoscale adsorbents not only adsorbed inorganic pollutants but also reduced NO3- and Cr6+ to NO2-, NH4+, and Cr3+ at pH=3, respectively. Thus, the nanoscale adsorbents (Fe3O4 and H-[Fe3O4]MgO) prepared and were capable of reductively adsorbing inorganic pollutants (e.g., NO3- and Cr6+) for environmental remediation.

abstract: This dissertation provides a fundamental understanding of the properties of mesoporous carbon based materials and the utilization of those properties into different applications such as electrodes materials for super capacitors, adsorbents for water treatments and biosensors. The thickness of mesoporous carbon films on Si substrates are measured by Ellipsometry method and pore size distribution has been calculated by Kelvin equation based on toluene adsorption and desorption isotherms monitored by Ellipsometer. The addition of organometallics cobalt and vanalyl acetylacetonate in the synthesis precursor leads to the metal oxides in the carbon framework, which largely decreased the shrink of the framework during carbonization, resulting in an increase in the average pore size. In addition to the structural changes, the introduction of metal oxides into mesoporous carbon framework greatly enhances the electrochemical performance as a result of their pseudocapacitance. Also, after the addition of Co into the framework, the contraction of mesoporous powders decreased significantly and the capacitance increased prominently because of the solidification function of CoO nanoparticles. When carbon-cobalt composites are used as adsorbent, the adsorption capacity of dye pollutant in water is remarkably higher (90 mg/g) after adding Co than the mesoporous carbon powder (2 mg/g). Furthermore, the surface area and pore size of mesoporous composites can be greatly increased by addition of tetraethyl orthosilicate into the precursor with subsequent etching, which leads to a dramatic increase in the adsorption capacity from 90 mg/g up to 1151 mg/g. When used as electrode materials for amperometric biosensors, mesoporous carbons showed good sensitivity, selectivity and stability. And fluorine-free and low-cost poly (methacrylate)s have been developed as binders for screen printed biosensors. With using only 5wt% of poly (hydroxybutyl methacrylate), the glucose sensor maintained mechanical integrity and exhibited excellent sensitivity on detecting glucose level in whole rabbit blood. Furthermore, extremely high surface area mesoporous carbons have been synthesized by introducing inorganic Si precursor during self-assembly, which effectively determined norepinephrine at very low concentrations. / Dissertation/Thesis / Ph.D. Chemical Engineering 2012

Foi realizado um experimento no aviário experimental do Departamento de Zootecnia da Universidade de São Paulo (USP), na Faculdade de Zootecnia e Engenharia de Alimentos (FZEA), em Pirassununga/SP com o objetivo de avaliar o efeito de dois níveis vitamínicos (comercial e OVN) com ou sem aflatoxina em dietas de frangos de corte no período de 1 a 42 dias. Foram utilizados 1800 pintinhos, machos, Cobb 500, distribuídos em um delineamento inteiramente casualizado em esquema fatorial 2 x 2 x 2 (2 níveis vitamínicos - comercial e OVN, 2 níveis de aflatoxina - 0 ppm e 0,5 ppm, e 2 níveis de adsorventes - 0 e 10 kg/ton), totalizando 8 tratamentos com 15 repetições de 15 aves cada. As dietas foram fornecidas fareladas e a base de milho e farelo de soja, formuladas segundo os níveis praticados por uma integradora da região. Para avaliar o desempenho foram analisados o consumo de ração, ganho de peso e conversão alimentar de 1 a 49 dias. Para avaliação de carcaça (rendimento de carcaça, peito e pernas), determinação de incidência de BBS e determinação do peso das vísceras abdominais e coração foram abatidas duas aves por repetição aos 45 dias. Os resultados mostraram que frangos de corte, machos, alimentados com nível OVN de vitaminas, apresentaram melhor ganho de peso, conversão alimentar, rendimento de carcaça e peito quando comparado com o nível comercial de vitaminas (P<0,05) e que as dietas contendo 0,5 ppm de aflatoxinas resultaram em menor ganho de peso, rendimento de carcaça, porcentagem de peito e aumentou o tamanho do coração e fígado do animal (P<0,05). O uso de 10kg/ton de adsorvente só apresentou resultado positivo no final da vida dos animais (dos 39 a 49 dias) (P<0,05) e somente na conversão alimentar. Esse estudo permite concluir que a aflatoxina resulta em perdas de desempenho e rendimento de carcaças e que o fornecimento de níveis ótimos de vitaminas melhora os resultados dessas características. O uso de adsorventes se mostrou inviável nesse estudo. / An experiment was conducted in an experimental aviary the Department of Animal Science, University of São Paulo (USP), the Faculty of Animal Science and Food Engineering (FZEA) in Pirassununga/SP, to evaluate the performance, carcass characteristics and weight of offal in broiler chickens fed with two levels of vitamins (commercial and VNO) with or without aflatoxin in broiler diets. Were used 1800 chicks, male, Cobb 500 distributed in a completely randomized 2 x 2 x 2 factorial arrangement (two vitamin levels, two levels of aflatoxin and two levels of adsorbents), totaling eight treatments with 15 replicates of 15 birds each. Diets were fed mash and corn and soybean meal, formulated according to the levels charged by an integrator in the region. To evaluate the performance were analyzed feed intake, weight gain, feed conversion from 1 to 49 days. For evaluation of carcass yield (carcass, breast and legs), determination of the incidence of BBS and determination of the weight of the abdominal viscera and heart were killed two birds per replicate at 45 days. The results showed that broilers, males fed VNO level of vitamins showed better weight gain, feed conversion, carcass yield and breast when compared to the commercial level of vitamins (P<0.05) and that diets intoxicated with 0.5 ppm of aflatoxin resulted in less weight gain, carcass yield, percentage of breast and increased the size of the heart and liver of the animal (P<0.05). The use of adsorbent 10kg/ton only had a positive result at the end of life of animals (from 39 to 49 days) (P<0.05) and only in the feed. This study indicates that aflatoxin results in loss of performance and carcass yield and the provision of optimal levels of vitamins improved the results of these characteristics. The use of adsorbents in this study proved to be unfeasible.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第19196号 / 農博第2135号 / 新制||農||1034(附属図書館) / 学位論文||H27||N4942(農学部図書室) / 32188 / 京都大学大学院農学研究科森林科学専攻 / (主査)教授 吉村 剛, 教授 髙野 俊幸, 教授 渡邊 隆司 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

The Carbon Capture and Storage method has been acknowledged for the capabilities of reducing up to 20% CO2 emissions. Development of porous carbon materials prepared from polyurethane foam adsorbent were investigated for capture of CO2. In this thesis work, the carbon material was chemically activated through the direct and indirect methods. Pre-carbonization, mass ratio KOH/char, activation temperature, and activation time, the effect of the preparation conditions on the porous adsorbent were evaluated for the purpose of managing pore sizes and developing high adsorption capacity of CO2. During the direct method, polyurethane foam was directly treated with KOH before activation. Whereas during the indirect method, the foam was pre-carbonized to form char, which was treated instead. The indirectly and directly activated adsorbent prepared at optimum conditions show adsorption capacities of 152,10 and 151,29 mg/g at 1 atm and 25°C respectively. The produced adsorbents were evaluated for their CO2 separation performance with a thermogravimetric analyser with 100% CO2. The CO2 uptake and pore sizes were directly affected by the different parameters. A moderate activation time and temperature presented a higher adsorption capacity, where it decreased after reaching a higher time and temperature. A higher KOH/char mass ratio leads to a higher CO2 uptake, where it steadily increases from the lowest mass ratio.

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