Les effluents de distillerie de mélasse de canne à sucre génèrent une pollution environnementale due à, d’une part de grands volumes et d’autres part à la présence de composés de couleur brune foncée, connus sous le nom de mélanoïdines. Dans cette étude, un consortium bactérien CONS8 isolé dans des sédiments de chute d'eau a été choisi comme consortium apte à la décoloration de la mélasse. On a montré que le consortium CONS8 pouvait décolorer, trois eaux usées synthétiques différentes, élaborées respectivement à base de Viandox (13,48% v/v), d’eau usée de mélasse de betterave (41,5% v/v) ou d’eau usée de mélasse de canne à sucre (20% v/v). Les décolorations obtenues en 2 jours seulement, en fioles d’Erlenmeyer sont respectivement de 9,5, à 8,02 et à 17,5%. Quatre bactéries prédominantes ont été identifiées dans le consortium CONS8 par l'analyse de l'rADN 16S. Sur la base de cette identification, et afin de réaliser la décoloration la plus élevée, un consortium bactérien artificiel MMP1 a été reconstruit avec Klebsiella oxytoca, Serratia mercescens (T2) et la bactérie inconnue DQ817737 (T4). Dans des conditions optimisées (aération, pH) le consortium bactérien MMP1 a permis de décolorer l'eau usée synthétique contenant de la mélanoidine à 18,3% en 2 jours. La comparaison de la décoloration par le consortium MMP1 avec un milieu abiotique a démontré que la décoloration était principalement due à l'activité biotique des cellules bactériennes, sans aucun phénomène d'adsorption. Un complément en minéraux et vitamines B n'a pas amélioré la décoloration de mélanoïdines avec le consortium bactérien MMP1. Enfin, les performances d'un bioréacteur à membrane pour traiter les eaux résiduaires synthétiques contenant de la mélanoïdine ont été évaluées à l’échelle du laboratoire. L'ensemencement du réacteur a été réalisé avec un inoculum sur la base du consortium MMP1. Le réacteur a fonctionné sous plusieurs conditions de temps de séjour hydrauliques (HRT) de 15, 20, et 40 heures. Les performances ont été analysées en termes de DCO (demande chimique en oxygène), décoloration et croissance de biomasse. Les résultats ont indiqué qu’une efficacité accrue d’élimination de la DCO et de la couleur ont été obtenues avec le HRT le plus long. / Distillery effluent from sugarcane molasses leads to an environmental pollution due to its large volume and the presence of dark brown colored compounds, known as melanoidins. In this study, a bacterial consortium CONS8 isolated from waterfall sediments in Maehongsorn province was selected as a molasses-decolorizing consortium. Consortium CONS8 was able to decolorize, only within 2 days, in Erlenmeyer flasks, three different synthetic wastewaters containing either Viandox sauce (13.5% v/v), beet molasses wastewater (41.5% v/v) or sugarcane molasses wastewater (20% v/v) at 9.5, 8.0 and 17.5%, respectively. Four predominant bacteria present in the consortium CONS8 were identified by the 16S rDNA analysis. To achieve the highest decolorization, the artificial bacterial consortium MMP1 comprising Klebsiella oxytoca, Serratia mercescens (T2) and unknown bacterium DQ817737 (T4), was constructed. Under optimized conditions (aeration, pH), the bacterial consortium MMP1 was able to decolorize the synthetic melanoidins-containing wastewater at 18.3% within 2 days. The comparison of decolorization by the consortium MMP1 with abiotic control proved that the color removal for synthetic melanoidins-containing wastewater medium was mainly due to biotic activity of bacterial cells, without any adsorption phenomena. Supplement of nutrients and vitamin B did not promote melanoidins decolorization by bacterial consortium MMP1. Finally, the performance of a membrane bioreactor (MBR) for synthetic melanoidins-containing wastewater treatment was investigated at laboratory scale, with a mineral membrane. The reactor seeding was made with the MMP1 bacterial consortium inoculum. The reactor was performed with several hydraulic retention times (HRT) of 15, 20, and 40 hours. The performances were analyzed in terms of COD, color removal and biomass in the reactor. The results indicated that the higher COD and color removal efficiency were achieved with the longer HRT.

The design of a tissue engineered pulmonary valve (TEPV) involves cells source(s), scaffold, in vitro conditioning system and the functional stability of the TEPV in vivo. Vascular cells (pulmonary artery smooth muscle (SMCs) and endothelial cells (ECs)) and periodontal ligament derived stem cells (PDLSCs) are relevant sources for the designing of TEPVs. In this study, labeling of these cell populations with super paramagnetic iron oxide microparticles along with concomitant usage of transfection agents was followed by visualization using magnetic resonance, while Intracellular iron oxide was confirmed by prussian blue staining and fluorescence microscopy. Also, the potential of PDLSC as a feasible source for TEPVs was investigated, expressing differentiative capacity to both SMC and EC phenotypes by a combination of biochemical and mechanical stimulation. Flow conditioning in a u-shaped bioreactor augmented collagen production in SMC-EC (99.5% for n=3) and PDLSC (93.3% for n=3) seeded scaffolds after a 3-week culturing period (P<0.05).

Neste trabalho, foi estudado o potencial biotecnológico, com ênfase na produção de biodiesel, de 25 espécies de macroalgas marinhas pertencentes às divisões Rhodophyta, Chlorophyta e Heterokontophyta coletadas no litoral brasileiro, avaliando-se a sua composição bioquímica e a sua taxa de fotossíntese. Também foram realizados estudos com 6 espécies de macroalgas coletadas na Baía do Almirantado, na Península Antártica, para comparar os resultados apresentados por esses organismos, que habitam um ambiente de condições extremas e adversas. Para a análise bioquímica, foram quantificados os pigmentos (clorofila a, para todos os grupos de macroalgas, e ficobiliproteínas -aloficocianina, ficocianina e ficoeritrina-, para as algas vermelhas), as proteínas e carboidratos solúveis totais e os lipídeos totais e ácidos graxos. As espécies Dictyota menstrualis e Ulva lactuca apresentaram os maiores valores de fotossíntese máxima. Foram observadas diferenças no conteúdo de clorofila a entre as espécies de macroalgas estudadas, sendo que os valores variaram de 0,20 ± 0,01 mg/g massa seca (Gigartina skottsbergii) a 6,82 ± 0,46 mg/g massa seca (Spatoglossum schroederi). Também houve grande variação no conteúdo de lipídeos, carboidratos e proteínas, sendo que os maiores valores foram encontrados em D. menstrualis (98,8 + 4,9 mg/g massa seca de lipídeos), Gracilaria mammillaris, Laurencia dendroidea e Plocamium cartilagineum (742,0 ± 31,9, 675,3 ± 11,0 e 660,2 ± 27,2 mg/g massa seca de carboidratos, respectivamente) e Palmaria decipiens e Aglaothamnion uruguayense (21,7 ± 1,7 e 18,0 ± 0,4 mg/g massa seca de proteínas, respectivamente). Houve grande variação na concentração e no perfil de ácidos graxos das espécies estudadas, sendo que D. menstrualis e S. schroederi foram as espécies que apresentaram os maiores valores. Além disso, D. menstrualis exibiu a maior proporção de ácidos graxos monoinsaturados. A partir dos resultados obtidos com as algas coletadas em campo, concluímos que D. menstrualis foi a espécie que apresentou as melhores características para ser utilizada como fonte para produção de biodiesel, devido a sua alta taxa fotossintetizante, alto teor de lipídeos e ácidos graxos e alto teor de ácidos graxos monoinsaturados. Dessa forma, D. menstrualis foi utilizada na segunda etapa do trabalho, sendo estabelecido o seu cultivo em laboratório, com uma taxa de crescimento (TC) de 11,1 % d-1. Foram realizados experimentos para avaliar os efeitos do aumento da concentração de dióxido de carbono (CO2), em condições de limitação e saturação de nitrogênio (na forma de nitrato, NO3-), sobre a TC, a fotossíntese, a atividade das enzimas nitrato redutase (NR), Anidrase Carbonica (AC) e Rubisco e sobre a composição bioquímica de D. menstrualis cultivada em biorreatores e sobre a captação do CO2 por D. menstrualis cultivada em laboratório. A TC, o conteúdo de proteínas e de N total no tecido de D. menstrualis foram maiores nos tratamentos contendo NO3-, independente da adição de CO2. Entretanto, houve um aumento nos valores de fotossíntese máxima, na atividade da Rubisco e NR, e no teor de carboidratos e lipídeos totais quando D. menstrualis foi cultivada em meio com adição de CO2, com saturação de NO3-. Houve pouca variação na atividade da AC entre os diferentes tratamentos testados. O perfil de ácidos graxos de D. menstrualis cultivada nos biorreatores foi caracterizado por um alto conteúdo de ácidos graxos poliinsaturados, com destaque para os omegas-3. Não houve diferença significativa na taxa de remoção de CO2 entre os tratamentos com e sem adição NO3-. A remoção de CO2 nos meios com e sem adição de CO2 foi alta, variando de 71,5% a 34,8%, respectivamente. Os resultados evidenciam que quando essa espécie foi cultivada em biorreatores, houve um aumento no seu teor de ácidos graxos poliinsaturados e &#969;-3, o que a torna mais interessante para ser utilizada como nutracêutico do que como matéria-prima para a produção de biodiesel. Apesar disso, a sua aplicação como fonte de biodiesel não deve ser desconsiderada, uma vez que alterações nas condições de cultivo acarretam em modificações no perfil de ácidos graxos. Com base nos resultados obtidos, as perspectivas para a produção de biodiesel a partir de macroalgas marinhas deverão contemplar estudos para encontrar as melhores condições de cultivo para que ocorra o aumento na biossíntese de ácidos graxos monoinsaturados. / The Biotehcnological potential, with biodiesel producing emphasis, on 25 species of marine benthic algae from the phylum Rhodophyta, Chlorophyta and Heterokontophyta collected along the Brazilian coast, were evaluated assessing their biochemical composition and their photosynthetic rate. Studies have also been performed with 6 seaweed species collected in Admiralty Bay, Antarctic Peninsula, to compare the results presented by these organisms inhabiting an environment of extreme and adverse conditions. For biochemical analysis, pigments (chlorophyll a, for all groups of macroalgae, and phycobiliproteins, allophycocyanin, phycocyanin and phycoerythrin, for the red algae), total soluble protein, total soluble carbohydrates and total lipids and fatty acids were quantified. The species Dictyota menstrualis and Ulva lactuca showed the highest values of maximum photosynthesis. There were differences in chlorophyll a content between the seaweeds studied, and the values ranged from 0.20 ± 0.01 mg / g dry mass (Gigartina skottsbergii) to 6.82 ± 0.46 mg / g dry weight (Spatoglossum schroederi). There was also wide variation in the content of lipids, carbohydrates and proteins, and the highest values were found in the species Dictyota menstrualis (98.8 ± 4.9 mg / g dry weight of lipids), Gracilaria mammillaris, Laurencia dendroidea and Plocamium cartilagineum (742, O ± 31.9, 675.3 ± 11.0 and 660.2 ± 27.2 mg / g dry weight of carbohydrates, respectively) and Palmaria decipiens and Aglaothamnion uruguayense (21.7 ± 1.7 and 18.0 ± 0, 4 mg / g dry weight of proteins, respectively). There was a wide variation on fatty acids contents and profile of the species studied; D. menstrualis and Spatoglossum schroederi showed the highest lipids values. In addition, D. menstrualis exhibited the highest proportion of monounsaturated fatty acids. From the results obtained with algae collected in the field, D. menstrualis is the species with the best characteristics to be used as a source for biodiesel production due to their high photosynthetic rate, high content of lipids and fatty acids and a high content of monounsaturated fatty acids. Thus, D. menstrualis was used in the second stage of this study, being established it\'s cultivation in the laboratory, with a growth rate (GR) of 11.1% d-1. Experiments to evaluate the effect of increasing carbon dioxide (CO2) concentration, under nitrogen (NO3-) limiting and saturation conditions, on the GR, photosynthesis, the activity of nitrate reductase (NR), carbonic anhydrase (CA) and Rubisco and on the biochemical composition of D. menstrualis grown in bioreactors and on the CO2 capture by D. menstrualis grown in the laboratory were performed. The GR, protein content and N content in the tissue of D. menstrualis were higher in treatments containing NO3-, regardless of the addition of CO2. However, there was an increase in the values of maximum photosynthesis, of Rubisco and NR activity, and of total soluble carbohydrates and total lipids when D. menstrualis was grown in medium with addition of CO2, with NO3- saturation. There was little variation in the AC activity among different treatments. The fatty acid profile of D. menstrualis cultivated in bioreactors was characterized by a high content of polyunsaturated fatty acids, especially the omegas-3. There was no significant difference in the rate of CO2 removal between treatments with and without NO3-. CO2 removal in medium with and without addition of CO2 was high, ranging from 71.5% to 34.8%, respectively. The results show that when this species was cultivated in bioreactors, there was an increase in its content of polyunsaturated fatty acids and &#969;-3, which makes it interesting for use as a nutraceutical than as raw material for biodiesel production. Nevertheless, its application as a source of biodiesel can not be disregarded, since changes in culture conditions lead to changes in fatty acid profile. Based on these results, the prospects for the production of biodiesel from marine macroalgae should include studies to find the best growing conditions to occur the increase in the monounsaturated fatty acids biosynthesis.

Lack of clean fresh water is one of the most pervasive problems afflicting people throughout the world. Efficient desalination of sea and brackish water and safe reuse of wastewater become an insistent need. However, such techniques are energy intensive, and thus, a good control design is needed to increase the process efficiency and maintain water production costs at an acceptable level. This thesis proposes solutions to the above challenges and in particular will be focused on two membranebased water systems: Membrane Distillation (MD) and Membrane Bioreactor (MBR) for wastewater treatment plant (WWPT). The first part of this thesis, Direct Contact Membrane Distillation (DCMD) will study as an example an MD process. MD is an emerging sustainable desalination technique which can be powered by renewable energy. Its main drawback is the low water production rate. However, it can be improved by utilizing advanced control strategies. DCMD is modeled by a set of Differential Algebraic Equations (DAEs). In order to improve its water production, an optimization-based control scheme termed Model Predictive Control (MPC) provides a natural framework to optimally operate DCMD processes due to its unique control advantages. Among these advantages are the flexibility provided in formulating the objective function, the capability to directly handle process constraints, and the ability to work with various classes of nonlinear systems. Motivated by the above considerations, two MPC schemes that can maximize the water production rate of DCMD systems have been developed. The first MPC scheme is formulated to track an optimal set-point while taking input and stability constraints into account. The second MPC scheme, Economic MPC (EMPC), is formulated to maximize the distilled water flux while meeting input, stability and other process operational constraints. The total water production under both control designs is compared to illustrate the effectiveness of the two proposed control paradigms. Simulation results show that the DCMD process produces more distilled water when it is operated by EMPC than when it is operated by MPC. The above control techniques assume the full access to the system states. However, this is not the case for the DCMD plant. To effectively control the closed-loop system, an observer design that can estimate the values of the unmeasurable states is required. Motivated by that, a nonlinear observer design for DCMD is proposed. In addition, the effect of the estimation gain matrix on the differentiation index of the DAE system is investigated. Numerical simulations are presented to illustrate the effectiveness of the proposed observer design. The observer-based MPC and EMPC are also studied in this work. Mathematical modeling of a wastewater treatment system is critical because it enhances the process understanding and can be used for process design and process optimization. Motivated by the above considerations, modeling and optimal control strategies have been developed and applied to the MBR-based wastewater treatment process. The model is an extension of the well-known Benchmark simulation models for wastewater treatment. In addition, model predictive control has been applied to maintain the dissolved oxygen concentration level at the desired value. In addition, a conventional PID controller has also been developed. The simulation results show that the both of controllers can be used for dissolved oxygen concentration control. However, MPC has better performance compared to PID scenario.

Explosives used in the mining industry release nitrate into the environment, causing concerns for the water quality in local river-systems. One way of reducing the nitrate loading into the environment is through a woodchip bioreactor. Water is passed through the bioreactor, where denitrifying microbial communities use the organic carbon from the substrate for energy, together with the nitrate. The efficiency of the denitrification process depends on various factors, including the type of carbon source selected and the temperature. To determine a suitable organic substrate to use in colder environments, column experiments were conducted, comparing different woodchip types. Three columns contained woodchips from pine, spruce and birch. In the fourth column, barley wheat was mixed with pine woodchips. An influent solution was pumped into the columns contained 50 mg/L nitrate-nitrogen. The effluent water was sampled and analysed twice per week for nitrate, nitrite and ammonium concentrations. The pH and alkalinity were analysed weekly to determine that denitrification was taking place. Three column conditions were tested. During the initial period, the columns were kept in 21 °C with a hydraulic residence time (HRT) of 6.3 days. In the following period, the columns were refrigerated at a temperature of 5°C. During the final period, the HRT was lowered to 3.2 days. After a 106-day runtime, it could be concluded that pine woodchips were the most effective substrate for denitrification in 5 °C temperature. The column with pine woodchips removed nitrate efficiently and produced the least amount of by-products and released DOC with a short HRT. The pine woodchips and barley straw column had high nitrite accumulation, and the nitrate removal rate in the birch and spruce woodchip columns was low in 5 °C conditions. / Sprängmedel som används inom gruvindustrin släpper ut nitrat i miljön, vilket kan leda till problem med vattenkvaliteten i lokala vattensystem. Ett sätt att reducera mängden nitrat som släpps ut är genom en bioreaktor med träflis. Vatten passeras genom bioreaktorn, där denitrifierande microbakteriella grupper använder det organiska kolet från substratet för energi, tillsammans med nitratet. Effektiviteten av den denitrifierande processen beror på flertalet faktorer, däribland vilken sorts kolkälla som valts ut och vilken temperatur bioreaktorn håller. För att identifiera ett bra organiskt substrat att använda i kallt klimat genomfördes ett kolumnexperiment som jämförde olika sorters träflis. Tre kolonner innehöll träflis från tall, gran och björk. I en fjärde kolonn blandades kornhalm med träflis från tall. En lösning med koncentrationen 50 mg/L kväve i form av nitrat pumpades in i kolonnerna. Utloppsvattnet från de fyra kolonnerna analyserades två gånger per vecka för koncentration av nitrat, nitrit och ammonium. pH och alkalinitet analyserades varje vecka för att se att denitrifikation skedde. Tre olika förutsättningar testades i kolonnerna. I den första perioden hölls kolonnerna i 21 °C med en hydraulisk uppehållstid på 6,3 dagar. I den följande perioden kyldes kolonnerna till 5 °C. I den sista perioden sänktes uppehållstiden till 3,2 dagar. Efter 106 dagar gick det att fastställa att tall-träflisen var det mest effektiva substratet för denitrifikation i 5 °C. Kolonnen med träflis från tall sänkte nitrathalten i vattnet och producerade minst biprodukter, samt frigjorde organiskt kol även vid kort uppehållstid. Kolonnen med tallflis och kornhalm ackumulerade mycket nitrit, och kolonnerna med träflis från björk och gran hade låga nivåer av nitrat-rening när temperaturen sänktes till 5 °C.

A significant by-product of bioethanol plants is whole stillage, commonly used to produce animal feed due to its nutritious value, has a potential to be used to produce various value-added products while eliminating a costly process step is an alternative approach. In this study, production and separation of additional ethanol, fungal biomass and enzyme were successfully achieved with the cultivation in membrane bioreactors in batch process condition. Process optimization studies regarding fermentation and filtration conditions were carried out. Up to 10.4 g/l ethanol per litre of used whole stillage can be produced in simultaneous saccharification and fermentation (SSF) condition without any pH adjustment and additional pretreatment step. Also, 50% diluted whole stillage provided 87% higher ethanol production comparing to non-diluted medium. Moreover, 71 % higher biomass production was obtained with the filtrate of 50% diluted whole stillage comparing to 25% diluted one. Considering the achieved results, a two-stage cultivation using SHF (Separate Hydrolysis and Fermentation) strategy in membrane bioreactors for separation of ethanol, lignin-rich stream, protein-rich fungal biomass and enzymes was proposed. The present thesis showed that the integration of filamentous fungi with membrane bioreactors can increase the range of products that can be produced from whole stillage.

This diploma thesis deals with the bioreactor system and its use for the production of heat and biogas. The bioreactor uses the composting and metanogation process of fermentation that humanity has known for hundreds of years, but the combination of these processes is a relatively unexplored area. The theoretical part of the thesis analyzes the existing possibilities of utilization of the heat generated in the compost, and also describes the used technology of small biogas stations and other small systems for biogas production. It follows the practical part of the work, when it was the task to design a bioreactor working at low temperatures during the winter. Part of the solution is the initial design and testing of the basic test structure of the bioreactor, followed by the implementation of a more advanced and more complex system, including a control and measuring center realized by a microcontroller.

Nitrogen and phosphorus are involved in many processes on the Planet Earth. Especially in agricultural areas water is contaminated by nutrients, which can cause the eutrophication of surface waters, and other problems. The solution could be use of denitrifying bioreactors, which are used for the reduction of high nitrate concentrations in shallow groundwaters. The subject of the thesis was the study of phosphorus removal in the denitrification bioreactor by steel turnings, which are constituent part of the organic load of the bioreactor. Steel turnings release Fe, which causes the precipitation and adsorption of P. Eight bioreactors were filled with poplar woodchips. To these columns just above the surface were added model water enriched with nitrate nitrogen, phosphate phosphate was added to 4 columns, where two of them were enhanced by the addition of steel turnings upstream of the wood medium. Sampling and the analyses of the samples were determined weekly, determination of the phosphorus, iron and other substances necessary for the detection of processes in the bioreactor was performed. The dependence of phosphorus removal on the bioreactor operating conditions was evaluated based on measured data, and the effect of iron on the biological denitrification process was also assessed. Steel turnings have been found to be effective in removing TP, but it is necessary to solve iron leaching in the future. The concentration of phosphorus was reduced up to 0 mg/l on the effluent from the denitrification bioreactors, efficiency of phosphorus removal reached 100 %. The presence of steel chips had no effect on denitrification speed. The denitrification process was also successful in the phosphorus removal columns. From the point of view of leaching of substances and iron, the removal of N and P seems to be preferable in dry period during stoppage with no water fillings. Shutdown of bioreactors with flooded filling caused high concentrations of leached iron up to 149 mg/l

Ammonium-nitrate based explosives (NH4NO3) used within the operations of Kiruna iron ore mine release nitrate (NO3-) into the environment, potentially having adverse effects on local river-systems. One way of reducing NO3- impacts to the environment is through a woodchip denitrifying bioreactor (DBR). Waste rock leachate is collected and passed through the bioreactor, where denitrifying microbial communities reduce NO3- to nitrogen gas (N2) using a carbon energy source. However, the efficiency of the DBR present in Kiruna iron ore mine has declined since the start of its operation leading to lower values of NO3-removal throughout the years.  Denitrification being a temperature dependent process, a heating device was installed to warm up the water prior to the DBR treatment to counterbalance this decrease. The effect of which has been assessed within this thesis. Chemical analyses encompassing NO3-, nitrite (NO2-), ammonium (NH4+), total organic carbon (TOC), phosphorus compounds (tot-P, PO4-P), and bacterial abundance were then investigated along a flowpath in the DBR. Overall, the results have shown that with an increase in temperature prior to the treatment, TOC, tot-P, PO4-P release was improved. Moreover, NO3- removal doubled compared to the previous year. TOC, tot-P and PO4-P are the result of the hydrolysis process, transforming the woodchips in available carbon source and providing nutrients for the bacteria to perform denitrification. Similarly, the bacterial abundance presented a significant increase with temperature. This suggest that both hydrolysis and bacteria growth enhancement with temperature ultimately participated in the improvement of the denitrification reaction. Moreover, a long-lasting effect of temperature on NO3- removal was observed during a following cold period as NO3- removal stayed above 45% after two months without heating. It is suggested that the cost of heating can be reduced by inducing “heat pulse” instead of continuous heating. Adding a heating system prior to treatment represents a promising solution for the future of sustainable mining, particularly for mines located in extreme climates such as Kiruna. / NITREM

No description available.