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1
Shieh, Martin T. "Combined bioreaction and separation in a simulated counter-current chromatographic bioreactor-separator system." Thesis, Aston University, 1994. http://publications.aston.ac.uk/9691/.
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The objective of this work has been to investigate the principle of combined bioreaction and separation in a simulated counter-current chromatographic bioreactor-separator system (SCCR-S). The SCCR-S system consisted of twelve 5.4cm i.d x 75cm long columns packed with calcium charged cross-linked polystyrene resin. Three bioreactions, namely the saccharification of modified starch to maltose and dextrin using the enzyme maltogenase, the hydrolysis of lactose to galactose and glucose in the presence of the enzyme lactase and the biosynthesis of dextran from sucrose using the enzyme dextransucrase. Combined bioreaction and separation has been successfully carried out in the SCCR-S system for the saccharification of modified starch to maltose and dextrin. The effects of the operating parameters (switch time, eluent flowrate, feed concentration and enzyme activity) on the performance of the SCCR-S system were investigated. By using an eluent of dilute enzyme solution, starch conversions of up to 60% were achieved using lower amounts of enzyme than the theoretical amount required by a conventional bioreactor to produce the same amount of maltose over the same time period. Comparing the SCCR-S system to a continuous annular chromatograph (CRAC) for the saccharification of modified starch showed that the SCCR-S system required only 34.6-47.3% of the amount of enzyme required by the CRAC. The SCCR-S system was operated in the batch and continuous modes as a bioreactor-separator for the hydrolysis of lactose to galactose and glucose. By operating the system in the continuous mode, the operating parameters were further investigated. During these experiments the eluent was deionised water and the enzyme was introduced into the system through the same port as the feed. The galactose produced was retarded and moved with the stationary phase to be purge as the galactose rich product (GalRP) while the glucose moved with the mobile phase and was collected as the glucose rich product (GRP). By operating at up to 30%w/v lactose feed concentrations, complete conversions were achieved using only 48% of the theoretical amount of enzyme required by a conventional bioreactor to hydrolyse the same amount of glucose over the same time period.
2
Ntwampe, Seteno Karabo Obed. "Multicapillary membrane bioreactor design." Thesis, Cape Peninsula University of Technology, 2005. http://hdl.handle.net/20.500.11838/897.
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Thesis (MTech (Chemical Engineering))--Cape Peninsula University of Technology, 2005The white rot fungus, Phanerochaete chrysosporium, produces enzymes, which are capable of degrading chemical pollutants. It was detennined that this fungus has multiple growth phases. The study provided infonnation that can be used to classify growth kinetic parameters, substrate mass transfer and liquid medium momentum transfer effects in continuous secondary metabolite production studies. P. chrysosporium strain BKMF 1767 (ATCC 24725) was grown at 37 QC in single fibre capillary membrane bioreactors (SFCMBR) made of glass. The SFCMBR systems with working volumes of 20.4 ml and active membrane length of 160 mm were positioned vertically. Dry biofilm density was determined by using a helium pycnometer. Biofilm differentiation was detennined by taking samples for image analysis, using a Scanning Electron Microscope at various phases of the biofilm growth. Substrate consumption was detennined by using relevant test kits to quantify the amount, which was consumed at different times, using a varying amount of spore concentrations. Growth kinetic constants were detennined by using the substrate consumption and the dry biofilm density model. Oxygen mass transfer parameters were determined by using the Clark type oxygen microsensors. Pressure transducers were used to measure the pressure, which was needed to model the liquid medium momentum transfer in the lumen of the polysulphone membranes. An attempt was made to measure the glucose mass transfer across the biofilm, which was made by using a hydrogen peroxide microsensor, but without success.
3
Du, Preez Ryne. "Development of a membrane immobilised amidase bioreactor system." Thesis, Link to the online version, 2008. http://hdl.handle.net/10019/1996.
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4
Grudzien, Lukasz Andrzej. "Enantioseparation using a counter-current bioreactor." Thesis, Brunel University, 2011. http://bura.brunel.ac.uk/handle/2438/6496.
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The potential of countercurrent chromatography (CCC) as a small footprint bioreactor/separator for manufacture of enantiopure chiral molecules was explored, using as a model reaction the isolation of L-amino butyric acid (L-ABA) from a DL-ABA racemate and the enantioselectivity of D-amino acid oxidase (DAAO). Bioconversion of D-ABA to ketobutyric acid (KBA) by DAAO, immobilised by selective partitioning in the stationary phase of the CCC centrifuge, was accompanied by separation of unreacted L-ABA from KBA by the countercurrent action of the centrifuge. For effective bioreactor/separator action, a high partition of the biocatalyst to the stationary phase was required in order to retain the biocatalyst in the coil, with differing partitions of substrates and products between the stationary phase (SP) and mobile phase (MP) so that these could be separated. Aqueous two-phase systems (ATPS) were the major two-phase systems used to provide SP and MP, as these are well reported to be effective in preserving enzyme activity. The distribution ratios of DL-ABA, KBA and DAAO were measured in a range of phases with polyethylene glycols (PEGs) of different molecular weights, different salts, and different compositions of PEG and salt, using an automated robotic method, developed for the purpose. A system of 14% w/w PEG 1000/ 14% w/w potassium phosphate, pH 7.6, gave the best combination of distributions ratios (CPEG phase/Csalt phase = CSP/CMP) for ABA, KBA and biocatalyst (DAAO) of 0.6, 2.4 and 19.6 respectively. A limited number of aqueous-organic and ionic liquid two-phase systems were also reviewed, but found unsatisfactory. CCC operating conditions such as substrate concentration, biocatalyst concentration, the mobile phase flow rate (residence time in the CCC coil), temperature, rotational speed and operational modes (single flow and multiple-dual flow) and types of mixing (cascade and wave-like) were optimised to produce total conversion of D-ABA to KBA, which was then completely separated from unreacted, enantiomerically pure (>99% ee), LABA. Advantages of the CCC bioreactor over conventional technology include reduced equipment footprint, cheaper running costs, and faster purifications. However, in its current format the drawbacks, such as enzyme instability and excessive optimisation time, reduce its commercial appeal. Additional investigations into the use of whole cell preparations of biocatalyst in the CCC bioreactor showed potential to overcome the problem of enzyme instability and this may in the future give the CCC bioreactor a place in the enantioseparation field.
5
Radocaj, Olgica. "Ethanol fermentation in a membrane bioreactor." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0015/MQ45840.pdf.
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6
Ramlogan, Anil Shiva. "Stem cell expansion and bioreactor development." Thesis, Queen Mary, University of London, 2010. http://qmro.qmul.ac.uk/xmlui/handle/123456789/676.
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A major challenge to the clinical success of cell-based tissue engineering strategies is the ability to obtain sufficient numbers of cells within an acceptable time frame. The expansion of cells on microcarriers within spinner flask bioreactor has shown promise in meeting that challenge. Spinner flask microcarrier technology is space-saving and media utilisation efficient. However, further optimisation in terms of, for example, seeding efficiency, expansion rates and harvest efficiency is necessary to realise the clinical potential of this technology. The present work is designed to improve cell expansion rates. It involves investigation of microcarrier composition and surface structure and spinner flask shear stress on cell growth. BMSC growth on PHBV microcarriers was superior to PCL and PLGA microcarriers and comparable to Cytodex 1 microcarriers. Lower density PHBV microcarriers showed promise as a superior alternative to Cytodex 1. Two different impeller designs employed in the w/o/w method of microcarrier synthesis resulted in smoother and rougher PCL microcarriers with Ra = 1.77 ± 0.42 μm to 6.4 ± 1.48 μm respectively. Superior BMSC growth was observed on the rougher PCL microcarriers. Differentiation potential along the osteogenic and adipogenic lineages of BMSCs expanded on the microcarrier types was retained. Particle Image Velocimetry was used to quantify shear stress within a spinner flask bioreactor. It was found that 80% of the shear stress was localised within the impeller region which occupied 55% of the bioreactor working volume. Shear stress increased as Cytodex 1 microcarrier concentration and impeller rotational speed increased. Superior BMSC growth rates on microcarriers were observed for the lowest shear stress experimental group (3.4 x 10-3 N/m2 ≤ impeller region mean shear stress ≤ 4.6 x 10-3 N/m2) as compared to the three higher shear stress groups (5.5 x 10-3 N/m2 ≤ mean shear stress ≤ 1.3 x 10-2 N/m2). Expanded BMSCs on the cytodex 1 microcarriers retained multipotentiality for the range of shear stresses investigated.
7
Griswold, Aaron A. (Aaron Alexander) 1981. "pH control in a miniaturized bioreactor." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/32812.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.Includes bibliographical references (leaf 18).
A miniaturized bioreactor with a volume on the order of 100 [micro]l has been built with the aim of increasing the efficiency of the screening process for various microbial cultures. Unlike larger reactors currently in use, the current miniaturized design lacks a method of pH control. Without pH control, cell growth can be hindered or even stopped altogether when the growing medium becomes too acidic. Using technology already in place to optically measure the pH inside the reactor in conjunction with a valve and a base-filled reservoir, a simple closed-loop (feedback) control system has been developed. The volume of base injected into the reactor must be minimized because the reactor itself is so small. Data is recorded and control signals are outputted by a computer running LabView software. While the control system developed in this thesis shows promise, further development is needed before it can be put to good use.
by Aaron A. Griswold.
S.B.
8
Carrier, Rebecca Lyn 1973. "Cardiac tissue engineering : bioreactor cultivation parameters." Thesis, Massachusetts Institute of Technology, 1999. http://hdl.handle.net/1721.1/8999.
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Thesis (Sc.D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2000.Includes bibliographical references.
Tissue engineering may be useful in fighting heart disease since it offers the possibility of creating functional tissue equivalents for scientific studies and tissue repair. In the present work, we examined how variations in cultivation parameters of a model tissue engineering system influenced cardiac tissue morphogenesis. The central hypothesis was that using a tissue engineering system consisting of isolated cardiac cells, polymer scaffolds, and tissue culture bioreactors, we could engineer cardiac muscle mimicking native tissue in structure and function in the presence of appropriate biochemical and physical signals. The specific objectives were to: ( 1) vary key parameters of the model tissue engineering system, and (2) structurally and functionally characterize engineered cardiac muscle so that effects of parameter variations could be assessed and engineered tissue could be compared to native tissue. Effects of key cultivation parameters, including (I) cell source, (2) cell seeding density, (3) cell seeding vessel, and (4) tissue culture bioreactor on structure and function of engineered cardiac cell-polymer constructs were studied. Advantages of seeding mammalian cells at high densities (6-Sx 106 cells/Smm diameter x 2mm thick scaffold) under mixed conditions and culturing constructs in rotating laminar flow bioreactors were demonstrated, but constructs had interiors (> IOOμm tissue depth) consisting of mostly empty space due to diffusional mass transport limitations. We attempted to overcome diffusional limitations by directly perfusing culture medium through the constructs. Perfusion significantly improved the uniformity of the cell distribution and enhanced expression of a differentiated cell phenotype in comparison to non-perfused (i.e. flask) cultures. Control of the cell microenvironment in the perfusion system was also used to study relationships between oxygen tension and properties of cardiac constructs. Oxygen tension was directly correlated with DNA and protein contents (r=0.88 and 0.89, respectively), aerobic metabolism (r=0.97), muscle protein expression, and ultrastructural differentiation. Characterization of cardiac construct structure, composition, cell phenotype, and in vitro function demonstrated cardiac specific protein expression, metabolic activity similar to that of native tissue, and differentiated ultrastructural features (e.g. sarcomeres). The results support the utility of engineered cardiac muscle as a native tissue model for in vitro studies and eventually for in vivo tissue repair.
by Rebecca Lyn Carrier.
Sc.D.
9
Germain, E. A. M. "Biomass effects on membrane bioreactor operations." Thesis, Cranfield University, 2004. http://dspace.lib.cranfield.ac.uk/handle/1826/11032.
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Diverse
operating parameters were investigated for their effects on biomass
characteristics, membrane fouling and aeration efficiency in submerged membrane
bioreactors (MBRS).
The characteristics of the solid phase of the biomass were affected by the biomass
state
(unstabilised, stabilising and stabilised) and by the SRT and HRT, whereas the
characteristics of the liquid phase appeared to be more dependent on inuent
composition and strength. Under operating conditions at constant SRT and HRT, the
biomass characteristics reached their stabilised state aer 1.0±0.3 SRT.
The
impact of membrane aeration, permeate flux and biomass characteristics was
determined for biomass at unstabilised state and at stabilised state. A transitional
permeate flux was observed between 16.5 and 22 l.m`2.h`l, below which no significant
fouling was observed regardless of the permeate flux, membrane airflow velocity and
biomass characteristics. Above transitional flux, membrane fouling increased and was
affected
by the permeate flux, the membrane aeration velocity and parameters either
characterising the liquid or the solid phase of the biomass depending on the
carbohydrate concentration of the liquid phase.
A
comparison of ne and coarse bubble aeration efficiency for biomass at
unstabilised state and at several airflow rates established that ne bubble aeration was
more efficient in tem of oxygen transfer rate, but led to similar values to coarse
bubble aeration for ot-factor. The effects of airflow rate and biomass characteristics on
oxygen transfer coefficient and ot-factor were determined for biomass coming from
pilot and full scale submerged MBRS treating municipal and industrial wastewaters.
Solids concentrations (correlated to viscosity), COD concentration of the liquid phase,
carbohydrate concentration of the EPS and volumetric airflow rate were found to
affect the aeration efficiency parameters. A transitional solids concentration existed
around 15 g.L", above which low or no oxygen transfer occurred.
10
BERNOCCO, MARCO. "Bioreactor engineering for tissue engineering application." Doctoral thesis, Politecnico di Torino, 2013. http://hdl.handle.net/11583/2513796.
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Lo scopo di questo lavoro di tesi è la caratterizzazione metrologica di un bioreattore con l’intento di aumentare la riproducibilità e l’affidabilità dei processi di Ingegneria tessutale (Tissue Engineering, TE). La Tissue engineering (TE) o ingegneria dei tessuti è la disciplina che studia la comprensione dei principi della crescita dei tessuti, e la loro applicazione per produrre tessuto funzionale per uso clinico o diagnostico. Uno dei principali scopi della TE è l’impiego di tessuti in crescita naturale extracorporea per la medicina rigenerativa, in altre parole lo sviluppo di strategie terapeutiche mirate alla sostituzione, riparazione, manutenzione e/o il miglioramento della funzione dei tessuti. L’ingegneria dei tessuti è caratterizzata da una grande interdisciplinarità che prevede la collaborazione di figure professionali con competenze molto differenti tra loro, quali biologi, chimici, fisici, matematici, ingegneri.
L’obiettivo è il progetto di un bioreattore che sia affidabile e controllabile per seguire l’evoluzione del processo. Questo deve essere eseguito applicando metodi metrologici allo studio del processo. La metrologia permette di poter quantificare l’incertezza di un fenomeno quindi di determinare la proprietà di un fenomeno, corpo o sostanza, che può essere distinta qualitativamente e determinata quantitativamente. Le fonti d’incertezza che caratterizzano l’incertezza finale o composta è legata: alla mancanza di conoscenza e alla variabilità del sistema e prevede strategie differenti per la loro gestione. La mancanza di conoscenza e può essere ridotta migliorando le informazioni sul sistema in esame, mentre la variabilità del sistema sotto studio, può essere gestita riducendo degli scenari presi in considerazione o definendo più precisamente il sistema studiato.
11
De, Ford D. "Scale-up of bioreactors : The concept of bioreactor number and its relation to the physiology of industrial micro-organisms at different scales." Thesis, Teesside University, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380694.
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12
Castillo, Moreno Patricia. "Développement d'un procédé de production d'hydrogène photofermentaire à partir de lactosérum." Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAI029/document.
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L'hydrogène est une source d'énergie précieuse en tant que source d'énergie propre et que matière première pour des innombrables industries.Les procédés biologiques de production d'hydrogène gagnent en importance en raison de leurs avantages opérationnelles et de leur polyvalence dans les substrats utilisés (y compris les eaux usées).Dans cette thèse doctoral, on a développé une méthodologie photo-fermentative de production d'hydrogène en utilisant du lactosérum en tant que substrat pour la bactérie Rhodobacter capsulatus IR3::LacZ et B10::LacZ.Ce projet a été réalisé en trois étapes, exposées dans les différents chapitres.Dans la première étape on a identifié les facteurs pertinents pour la production de l'hydrogène avec du sérum synthétique en utilisant la méthodologie de plan d'expériences.Les résultats de cet étape on a obtenu quatre modèles statistiques et on a choisi la souche IR3::LacZ pour les expériences avec du lactosérum industriel.Le rendement volumétrique maximal et le rendement produit / substrat Y P/S obtenus pour la première étape ont été de 64 ml h-1L-1 et 2,08 mol H2 mol-1 C (“C” représente la source de carbone dans ce cas lactose et lactate) pour la solution amortissant le phosphate et 43.01 ml h-1L-1 y 2.52 mol H2 mol-1 C pour la solution Kolthoff.Dans la deuxième étape, on a évalué la production d'hydrogène avec du lactosérum industriel. On a appliqué un pré-traitement de trois étapes avant d'utiliser le lactosérum comme substrat : réduction du contenu gras, déprotéinisation et stérilisation. On a obtenu un modèle validé qui décrit la production d'hydrogène seulement pour la solution amortissant de phosphate. Le rendement volumétrique maximal et le YP/S ont été de 45.93 ml h-1L-1 et de 2.29 mol H2 mol-1 C respectivement. On a déterminé que l'addition d'une étape d’homo-fermentation au processus de prétraitement es avantageuse au rendement du processus. On a obtenu une productivité volumétrique de 69.71 ml h-1L-1 et de YP/S de 2.96 mol H2 mol-1 CLa troisième étape a été la mise à l'échelle des expériences à réacteurs de 1,5 L pour sérum synthétique et de 1L pour serum industriel. On a décelé de la contamination dû à la présence d'un processus de fermentation, lequel a généré une haute production de biogas composé exclusivement par H2 y CO2 ce dernier dans une concentration non superieur à 30% (v/v).Pour ces raisons, on a conclu que conclu que le processus de production intégré, en couplant la fermentation obscure et la photo-fermentation est une option avec un énorme potentiel pour l'utilisation de lactosérum comme substrat dans la production d'hydrogèneHydrogen is a valuable gas use as a clean energy source and feedstock for some industries. Biological hydrogen production processes are gaining importance due to their operational conditions and versatility in the substrates (including wastewater). A hydrogen production photo fermentative methodology was developed using cheese whey as a substrate for the bacteria Rhodobacter capsulatus strain IR3::LacZ and B10::LacZ . The project was carried out in three stages.The purpose of the first stage is to identify the relevant factors to produce hydrogen for a synthetic whey medium in a photofermentation process, using the Design of Experiments methodology. The products of this stage are four statistical models, obtained for each strain and buffer solution studied. The strain IR3::LacZ was selected for the experiments with industrial whey as substrate. The maximum volumetric yield and the product/substrate yield YP/S were 64 ml h-1L-1 and 2.08 mol H2 mol-1 C (C is the carbon source in this case lactose and lactate) and 43.01 ml h-1L-1 and 2.52 mol H2 mol-1 C for phosphate buffer and Kolthoff buffer, respectively.In the second stage the production of hydrogen with industrial whey was evaluated. A three-step pre-treatment was applied before using industrial cheese whey as substrate: fat reduction, deproteinization and sterilization. A validate statistical model describing hydrogen production was only obtained for phosphate buffer. The maximum volumetric yield and the product/substrate yield YP/S were 45.93 ml h-1L-1 and 2.29 mol H2 mol-1 C respectively. The addition of an homofermentation to the pretreatment improved the production yield, in this case a volumetric productivity of 69.71 ml h-1L-1 and a YP/S of 2.96 mol H2 mol-1 C were obtained.The third stage was the scale-up to 1.5 and 1 reactor L for synthetic whey and 1L for synthetic and industrial whey respectively. A fermentative process appeared due to a bacterial contamination, leading to a high biogas production. Biogas was exclusively composed of H2 and CO2 the last in a concentration not exceeding 30% (v/v). For this reason, it was concluded that the integrated production process coupling dark and photo fermentations) is an option with great potential for the use of whey as substrate in the production of hydrogen
13
Fernandes, Freitas Dino Miguel. "A mechano-perfusion bioreactor for tissue engineering." Doctoral thesis, Universitat de Girona, 2019. http://hdl.handle.net/10803/668821.
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Tissue Engineering plays a vital role in tissue construct to repair, maintain
or replace tissues. Those tissues can be cultivated in vivo or in vitro using
devices such as bioreactors. There are several approaches to create the
necessary tissues, but one of the most popular and successful is by using
scaffold constructs to provide the required stability and support. After the
cells being implanted on the scaffolds, they are then inserted in the
bioreactors.
Those bioreactors seek to mimic the conditions provided to cells by the human
body. This issue by itself presents several challenges where it is required,
to bioreactors, besides the optimum environment in terms of temperature,
nutrients, the creation of the necessary stimulus to cells to differentiate
and proliferate.
In this work, is presented a novel concept of bioreactor for Tissue
Engineering that can provide multiples stimulus when cultivating the tissue.
To achieve an optimised design was performed several numerical simulations to
access the best design parameters. For this, it was taken into account
several variables such as fluid velocity, the proximity of the inlet/outlet
to the scaffold, directions of the fluid and the impact of the liquid on the
scaffold and subsequently the cells by analysing the wall shear stress
provoked by the fluid flowL’enginyeria de teixits té un paper fonamental en la construcció de teixits per reparar, mantenir o substituir teixits. Aquests teixits es poden cultivar in vivo o in vitro mitjançant dispositius biomèdics com ara bioreactors. Hi ha diversos enfocaments per crear els teixits necessaris, però un dels més populars i amb èxit, és utilitzar construccions d’estructures semblants a les bastides, anomenats scaffolds, per proporcionar l'estabilitat i el suport necessaris a les cèl·lules. Després de la implantació de les cèl·lules a les bastides, es col·loquen a l’interior dels bioreactors. Aquests bioreactors pretenen imitar les condicions que proporciona el cos humà a les cèl·lules. Aquesta qüestió per si mateixa presenta diversos reptes en què es requereix, als bioreactors, a més de l’ambient òptim en termes de temperatura i nutrients, la creació de l’estímul necessari perquè les cèl·lules es diferenciïn i proliferin. En aquest treball, es presenta un concepte nou de bioreactor per a l’enginyeria de teixits que pot proporcionar estímuls múltiples al cultiu del teixit. Per aconseguir un disseny optimitzat s’han realitzat diverses simulacions numèriques per accedir als millors paràmetres de disseny. Per a això, es va tenir en compte diverses variables com la velocitat del fluid, la proximitat de l’entrada / sortida a la scaffold, les direccions del fluid i l’impacte del fluid sobre la scaffold i, posteriorment, sobre les cèl·lules mitjançant l’anàlisi de la tensió de cisalla provocada pel flux de fluids
14
Uyar, Basar. "Hydrogen Production By Microorganisms In Solar Bioreactor." Phd thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/2/12609252/index.pdf.
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The main objective of this study is exploring the parameters affecting photobiological hydrogen production and developing anaerobic photobioreactor for efficient photofermentative hydrogen production from organic acids in outdoor conditions. Rhodobacter capsulatus and Rhodobacter sphaeroides strains were used as microorganisms.
EU project &ldquoHyvolution&rdquo
targets to combine thermophilic fermentation with photofermentation for the conversion of biomass to hydrogen. In this study, the effluent obtained by dark fermentation of Miscanthus hydrolysate by T. neapolitana was fed to photobioreactor for photofermentation by R. capsulatus. Hydrogen yield was 1.4 L/Lculture showing that the integration of dark and photofermentation is possible. Innovative elements were introduced to the photobioreactor design such as removal of argon flushing. An online gas monitoring system was developed which became a commercial product. It was found that the light intensity should be at least 270 W/m2 on the bioreactor surface for the highest hydrogen productivity and the hydrogen production decreased by 43 % if infrared light was not provided to the bioreactor. Scale-up of photofermentation process to 25L was achieved yielding 27L hydrogen in 11 days by R. capsulatus on acetate/lactate/glutamate (40/7.5/2 mM) medium. The outdoor application of the system was made. Shading and water spraying were adapted as cooling methods for controlling the temperature of the outdoor bioreactor. It was found that uptake hydrogenase deleted mutant of R. capsulatus show better hydrogen productivity (0.52 mg/L.h) compared to the wild type parent (0.27 mg/L.h) in outdoor conditions. It was also shown that the hydrogen production depended on the sunlight intensity received.
15
Price, G. Alexander. "LONG-TERM NITROGEN MANAGEMENT IN BIOREACTOR LANDFILLS." NCSU, 2001. http://www.lib.ncsu.edu/theses/available/etd-20011214-153926.
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One scenario for the long-term nitrogen management in landfills is ex-situ nitrification followed by denitrification in the landfill. The objective of this research was to measure the denitrification potential of actively decomposing and well decomposed refuse. A series of 10-L reactors that was actively producing methane was fed 400 mg NO3-N /L every 48 hr for19 to 59 days. Up to 29 nitrate additions were either completely or largely depleted within 48 hr of addition and the denitrification reactions did not adversely affect the refuse pH. Nitrate did inhibit methane production but the reactors recovered their methane-producing activity with the termination of the nitrate addition. In well decomposed refuse, the nitrate consumption rate was reduced but was easily stimulated by the addition of either acetate or an overlayer of fresh refuse. Addition of a high acetate to nitrate ratio did not lead to the production of NH4+ by dissimilatory nitrate reduction. Although the population of denitrifying bacteria decreased by about five orders of magnitude during refuse decomposition in a reactor that did not receive nitrate, rapid denitrification commenced immediately with the addition of 400 mg NO3-N/L. These data suggest that the use of a landfill as a bioreactor for the conversion of nitrate to a harmless byproduct, nitrogen gas, is technically viable.
16
Peeling, Louise. "Landfill drainage as a fixed-bed bioreactor." Thesis, Queen Mary, University of London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298468.
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Pavasant, Prasert. "Modelling of the extractive membrane bioreactor process." Thesis, Imperial College London, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266478.
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Boontawan, Apichat. "A membrane bioreactor for biotransformation of terpenes." Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.413713.
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19
Splendiani, Antonietta. "Biofilm control in an extractive membrane bioreactor." Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.401883.
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Jones, Franck Anderson. "Modelling of novel rotating membrane bioreactor processes." Thesis, Brunel University, 2017. http://bura.brunel.ac.uk/handle/2438/16345.
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Previous membrane researches undertaken over the years to develop general deadend filtration models made use of an approach that combined all three classical fouling mechanisms, namely, pore blocking, pore constriction and cake filtration. More recently researchers have modified and adapted this modelling approach for a cross flow side-stream membrane bioreactor (MBR) system. Literature also reveals that there have been numerous recent experimental studies conducted on rotating membrane bioreactor (RMBR) systems. Some of these studies have resulted in the creation of RMBR models of the membrane fouling process as well. However, simulation and modelling of the fouling in RMBRs is still a nascent topic to date due to poor understanding and great complexity of the system hydrodynamics involved. Even when models are developed, they are either too complex to be useful at operational level, or not comprehensive enough to express all possible operational scenarios. In many cases they are simply too difficult to calibrate and thus ending up being more suited as research tools rather than for direct process control. As such, further research is required in this area. The research reported in this thesis consists of the development and validation of a RMBR system fouling model that incorporates all three classical fouling mechanisms. This thesis work is divided into two main sections. On top of a literature review that thoroughly describes the background theory and general information on MBRs along with their state of the art, the first section of the thesis also explains the specific methodologies used to accomplish all the main tasks carried out in this research work. The first step of these methodologies involves the setting-up of a rotating MBR system process based upon the FUV-185-A15R Flexidisks membrane module that was developed by Avanti Membrane Technology (USA). This system was used to collect the majority of the data used in this thesis. Since some of these data outputs were compared against non-rotating MBR systems, a similar setting-up process for a bespoke static square MBR system was carried out as well. Using synthetic wastewater in conjunction with activated sludge, mixed liquor suspended solids in both MBR system bioreactors were increased in levels over time to desired levels (i.e. by periodic excess sludge wasting). Trans-membrane pressure (TMP)-stepping fouling data was then acquired from operations of these membrane ultrafiltration processes. This data was obtained by measuring the flux decline or TMP increase. Following data collection, a dynamic fouling model for this RMBR system was then created in Matlab (using the Genetic Algorithm function). To do this, hydrodynamic regimes such as air scouring and rotating shear effects along with all the three classical fouling mechanisms were included in the mathematical fouling model that was created from first principles. For the purpose of comparison, a similar fouling model was created without incorporating the rotational effects for the static square MBR system. This included modelling of the hydrodynamics as well. Finally, both these models were validated and calibrated using the data that were collected from both laboratory-based MBR systems. The second phase of the thesis explores the numerous outputted results produced via model simulations which were then discussed and analysed in great detail. Results from this research indicate that the mathematical models give a decent portrayal and description of the fouling mechanisms occurring within a rotating MBR system. It was found that the rotational mechanisms in terms of fouling prevention accounted for only twelve percent of cake removal with the rest being accomplished through the air scouring mechanism. However, it was found that although the slowly rotating spindle induced a weak crossflow shear, it was still able to even out cake build up across the membrane surface, thus reducing the likelihood of localised critical flux being exceeded, which would lead to dramatic loss of flux. Furthermore, when compared against the static MBR system, the study concluded that a rotating MBR system could increase the flux throughput by a significant amount. In conclusion, RMBR systems appear to represent alternative viable solutions when compared against the traditional static MBR systems that currently dominate the industrial and municipal marketplace. In future, RMBR systems may become the systems of first choice once there is a better understanding of the rotational processes, and once research and design into this sector broadens. Future study areas should thus focus on: whether the forces acting on an activated sludge particle during rotation have a significant effect on the fouling or the shear hydrodynamic regimes; whether activated sludge and benchmark models could be created for rotating MBRs whilst including the shear effects and hydrodynamic regimes; whether model predictive control using these developed RMBR models would enhance efficiency gains within an operational plant; and, whether the real measured soluble microbial products (SMP) concentrations could be used to create an even better SMP predictive model that accurately explains fouling behaviour.
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Mitchel, Jennifer (Jennifer A. ). "Characterization of a perfused 3D liver bioreactor." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40450.
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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2007.Includes bibliographical references (leaves 17-18).
The liver is the most important site of drug and nutrient metabolism in the body, and we desire an accurate in vitro model that allows us to perform long term drug and metabolism studies. To this end of developing an assaying tool, I used an existing multi-well bioreactor that allows for formation of perfused, three dimensional tissue structures, and began characterization of tissue behavior over time. One issue in the multi-well bioreactor is the unknown profile of cell retention over time, which is an important specification for normalizing data from drug metabolism studies. Number of cells can be indirectly assessed by measuring total protein or RNA levels when direct counting is problematic. To the end of comparing these methods, an additional goal of this thesis was to develop a protocol to measure both protein and RNA levels from a single sample using the commercially available reagent RNAlater. RNAlater was shown, however, to be incompatible with certain existing protocols for isolating both protein and RNA.
by Jennifer Mitchel.
S.B.
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Voigt, Elizabeth Elena. "Hydrodynamic Characterization of an Arterial Flow Bioreactor." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/34066.
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An in vitro arterial flow bioreactor system for the generation of physiological flows in a biological environment was designed, constructed, and characterized. The design was based on models previously used to investigate the response of endothelial cells to shear. The model interfaces a bioreactor with flow elements to compose a flow loop that reproduces arterial flow conditions within the bioreactor. High-resolution (8.6 microns) time-resolved (4 ms) velocity field measurements within the bioreactor were obtained using Particle Image Velocimetry (PIV). Two physiological flows were considered, corresponding to medium human arteries at rest and exercise conditions: first, with an average Reynolds number of 150 and a Womersley parameter of 6.4, and second, with an average Reynolds number of 300 and a Womersley parameter of 9.0. Two cases were considered: first, using a smooth artery section, and second, with a confluent layer of human microvascular endothelial cells grown on the inner surface of the artery section. The instantaneous wall shear stress, time-averaged wall shear stress, and oscillatory shear index were computed from the velocity field measurements and compared for the cases with and without cells. These measurements were used to assess the value of the system for measurement of correlations between fluid dynamics and the response of biological tissue. It was determined that the flow present in such a system is not an accurate reproduction of physiological flow, and that direct measurement of the flow is necessary for accurate quantification of cellular response to fluid parameters.Master of Science
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Myers, Michael John. "Laboratory Scale Solid State Landfill Bioreactor Design." The Ohio State University, 1999. http://rave.ohiolink.edu/etdc/view?acc_num=osu1393077896.
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Williams, Chrysanthi. "Perfusion bioreactor for tissue-engineered blood vessels." Diss., Available online, Georgia Institute of Technology, 2004:, 2003. http://etd.gatech.edu/theses/available/etd-06072004-131410/unrestricted/williams%5Fchrysantyhi%5F200405%5Fphd.pdf.
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Mamo, Julian. "Assessment and optimisation of the operation of integrated membrane system for wastewater reclamation." Doctoral thesis, Universitat de Girona, 2018. http://hdl.handle.net/10803/667844.
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The combination of two membrane technologies coupled together in series has become a standard technology when it comes to producing reclaimed water of high quality for potable reclamation or industrial applications. This combination of two membrane processes is referred to as integrated membrane systems (IMS). Despite the widespread experience gained utilizing such a process technology around the world, there are a number of aspects of the process technology which require further investigation including the fate of compounds of emerging concern (CEC), the control of N-Nitrosodimethylamine (NDMA) formation, the use of energy associated with the process and the total cost of producing the reclaimed water, and monitoring membrane integrity in RO treatment processes. The objective of this work was to further the knowledge in one aspect related to each of these four challenges and then bring each of these areas together in the discussion to understand whether proposing a decision support system for the online monitoring and operation of integrated systems would allow improvements to the current state-of-the-art.La combinació de dos tecnologies de membrana acoblades en sèrie ha esdevingut un tecnologia consolidada degut a la capacitat de produir aigua d’elevada qualitat i potencialment reutilitzable per aplicacions industrials com fins i tot per ser potabilitzada. Tot i l’elevada experiència adquirida en aquests processos combinats, encara hi ha aspectes del procés que calen una investigació més profunda que inclogui el coneixement sobre l’eliminació dels compostos emergents, el control de la formació de N-Nitrosodimetilamines (NDMA), l’ús de l’energia associada amb el procés incloent el cost total de produir l’aigua reutilitzable, i el seguiment de la integritat de la membrana en el tractament amb osmosi inversa (OI). L’objectiu d’aquest treball recau en avançar en el coneixement dels aspectes relacionats amb cada un dels quatre reptes esmentats, per aconseguir discutir de forma conjunta la millor forma d’integrar aquest nou coneixement adquirit proposant un sistema d’ajuda a la decisió pel control i seguiment de l’operació de sistemes integrats de membrana (SIM).
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Ouyang, Anli. "Embryonic stem cell culture in fibrous bed bioreactor." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1149001795.
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Oliveira, Taís Lima de. "Desenvolvimento de processo de fermentação em biorreator para produção de prolactina humana secretada no espaço periplásmico de Escherichia coli." Universidade de São Paulo, 2008. http://www.teses.usp.br/teses/disponiveis/85/85131/tde-07072009-152955/.
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A Prolactina (PRL) é um dos hormônios mais versáteis em termos de ação biológica. Sua ação mais conhecida está relacionada com o estímulo da lactação e regulação do crescimento e da diferenciação da glândula mamária; também apresenta importante aplicação diagnóstica. Somando os crescentes estudos sobre suas possíveis aplicações terapêuticas, fica cada vez mais notória a necessidade da obtenção desse hormônio puro, biologicamente ativo e na sua forma autêntica.O objetivo fundamental desse projeto foi a produção de hPRL em escala laboratorial a partir de bactérias (E.coli) modificadas geneticamente, utilizando um sistema de expressão baseado no promotor Lambda () PL, o mesmo utilizado com sucesso em nosso laboratório na expressão do hGH. Descrevemos nesse trabalho um processo de cultivo em biorreator, onde não foi utilizado o repressor cIts, uma proteína termo-sensível que usualmente é utilizada para inibir o funcionamento do promotor PL durante crescimento a 30ºC. O processo de cultivo apresenta basicamente três etapas: na primeira etapa o crescimento é realizado sem adição contínua de nutrientes (cultivo em batch), na segunda etapa ocorre adição contínua de nutrientes e carboidrato (cultivo em fed-batch) e na última etapa é realizada a ativação, caracterizada pelo aumento da temperatura mantendo-se a adição de nutrientes e carboidrato. Esse processo de fermentação rápido e flexível, com duração média de 20 horas, permitiu obter uma biomassa final correspondente à densidade óptica de aproximadamente 30 A600nm (unidades ópticas de absorbância em 600nm) e com uma expressão da ordem de 1g de hPRL mL-1 A600 -1, as mais altas já relatadas para secreção de prolactina no espaço periplásmico. A hPRL monomérica foi purificada e caracterizada por métodos físico-químicos e biológicos, os quais confirmaram a sua atividade biológica e imunológica, o seu correto processamento e uma massa molecular relativa (Mr) de 22.906.Prolactin (PRL) is one of the most versatile hormones in terms of biological action. His best known action is related to the stimulation of lactation and regulation of growth and differentiation of the mammary gland; it also has wide important diagnostic applications. Considering all the increasing studies on its potential therapeutic applications, the need for obtaining this hormone in its pure, biologically active and authentic form becomes clearer and clearer. The fundamental objective of this project was the production of hPRL on the laboratory scale, from genetically modified bacteria (E.coli), using an expression system based on Lambda () PL promoter, the same successfully used in our laboratory for the expression of hGH. We set up a cultivation process in bioreactor, where the repressor (cIts), a thermo-sensitive protein that is usually used to inhibit the PL promoter during the growth phase (30°C). The cultivation process presents basically three stages: the first step in was not used the growth is carried out without the continuous addition of nutrients (batch cultivation), the second step in which a continuous addition of nutrients and carbohydrate occurs (fed-batch cultivation) and a final step when activation is carried out. The latter is characterized by an increased temperature, still maintaining the addition of nutrients and carbohydrate. This fast and flexible process of fermentation, with the average duration of 20 hours, led to a final biomass of approximately 30 A600nm (units of optical absorbance at 600nm), with the expression of about 1g of hPRL mL-1A600 -1, the highest ever reported for the secretion of prolactin in the periplasmic space. Monomeric hPRL was purified and characterized by physical-chemical methods and biological assays, which confirmed its biological and immunological activity, correct processing and a relative molecular mass (Mr) of 22,906.
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Wolfe, Kevin Brian. "First principles and artificial neural networks modeling of waste temperatures in a forced-aeration landfill bioreactor : a dissertation presented to the faculty of the Graduate School, Tennessee Technological University /." Click access online version, 2006. http://proquest.umi.com/pqdweb?index=96&did=1115122181&SrchMode=1&sid=1&Fmt=6&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1256313131&clientId=28564.
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Liu, Wenjun. "High strength industrial wastewater treatment using membrane bioreactors : a novel extractive membrane bioreactor for treating bio-refractory organic pollutants in the presence of high concentrations of inorganics: application to acidic effluents." Thesis, University of Bath, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.369997.
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Hayes, William. "Ethanol production from glucose by Saccharomyces cerevisiae in an anaerobic gas-solid fluidised bed fermenter." Thesis, University of Lincoln, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.263961.
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McMahon, Matthew James Lee. "Development of a sulfate reducing packed bed bioreactor for use in a sustainable hydrogen production process." Thesis, Kingston, Ont. : [s.n.], 2007. http://hdl.handle.net/1974/712.
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Minervini, Mirko. "A membrane bioreactor for enzyme recovery from saccharification." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019.
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The present work is part of a bigger project which, as a final goal, has the development and the optimization of a membrane integrated saccharification process for the production of corn based sugar syrups in Cargill plants. Nowadays, the starch saccharification process is mainly performed through a two steps batch bioreactor mediated by hydrolytic enzymes. First, a fast preliminary hydrolysation occurs, where the long polymeric starch chains are cut and of a maltodextrin mixture is produced. Then, the liquified starch is sent to a batch bioreactor where different hydrolytic enzymes, according to the final product type, complete the starch conversion into molecules at low degree of polymerization (DP). The optimisation idea is to use a membrane bioreactor to operate the saccharification in continuous mode, where the enzymes are separated from end products with the help of a selective ultrafiltration membrane. The process under investigation is an innovative technology with high potentiality which could allow not only to increase the reaction yield, but also to save on downstream costs. The Cargill plant of Castelmassa (RO) is taken as reference for this work, in particular, the dextrose line that produces highly concentrated sucrose syrups. Therefore, starting from the currently adopted plant set-up the best operative conditions for a hypothetical plant development with membrane bioreactors will be determined. The experimental work aimed at the optimisation of the membrane filtration stage was performed in the MEMLAB laboratories at DICAM, of the university of Bologna, using a 10 kDa membrane selected from a previous study. The optimisation of reaction conditions was performed in Castelmassa, using the real plant feed to the saccharification stage.
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Hu, Alan Yung-Chih. "Anaerobic in-tank membrane bioreactor for wastewater treatment." Thesis, Imperial College London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.414422.
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Janekeh, Massoud. "Ethanol fermentation in a gas-lift bioreactor system." Thesis, Heriot-Watt University, 1988. http://hdl.handle.net/10399/933.
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Ball, James. "Biotransformations operated in a two phase membrane bioreactor." Thesis, University of Kent, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362309.
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Lant, Paul Andrew. "Adaptive Inferential Estimation : application to an industrial bioreactor." Thesis, University of Newcastle Upon Tyne, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239732.
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Cresswell, Michael Alan. "Development of a fluidised bed bioreactor for actinomycetes." Thesis, Manchester Metropolitan University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.290425.
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Dumouchel, Matthew P. (Matthew Paul). "Bioreactor Fill Process Control Using Inline Concentration Measurement." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/90800.
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Thesis: M.B.A., Massachusetts Institute of Technology, Sloan School of Management, 2014. In conjunction with the Leaders for Global Operations Program at MIT.Thesis: S.M., Massachusetts Institute of Technology, Department of Chemical Engineering, 2014. In conjunction with the Leaders for Global Operations Program at MIT.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 75-77).
Some biopharmaceutical companies have responded to evolution of the competitive landscape by placing additional emphasis on reducing their costs of manufacturing as a means of maintaining competitiveness. The prototypical current generation biopharmaceutical drug substance manufacturing facility requires a large upfront capital investment. Improving efficiency of use of existing facilities, such as by improving production throughput through the adoption of technology, represents one way in which a company may reduce its costs of manufacturing and/or avoid or delay investments in additional capacity needed to meet future demand. Reducing the variability in the performance of a liquid filling operation taking place during the protein production step is desirable, because it: (1) enables process optimization, including potential throughput expansion, (2) demonstrates control over the process, and (3) improves step yield reproducibility. The technical and economic bases for the implementation of an alternative process control strategy intended to reduce this variability are presented. This strategy involves controlling the fill operation using an inline concentration measurement of the parameter of interest. An engineering-probabilistic approach, consisting of a transient concentration profile model built into a Monte Carlo framework, is applied to predict the variability of the performance of a concentration-based control strategy for filling an agitated, gassed bioreactor. An optimization methodology for selecting an appropriate post-fill target concentration and for quantifying the economic benefit of reducing variability is proposed.
by Matthew P. Dumouchel.
M.B.A.
S.M.
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Goh, Shireen. "Micro-bioreactor design for Chinese hamster ovary cells." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/82368.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 195-203).
The research objective is to design a micro-bioreactor for the culture of Chinese Hamster Ovary (CHO) cells. There is an increasing demand for upstream development in high-throughput micro-bioreactors specifically for the recombinant CHO cell line, an important cell line for producing recombinant protein therapeutics. In order to translate a micro-bioreactor originally designed by our group for bacteria to CHO cells, there would need to be significant modifications in the design of the micro-bioreactor due to the extreme sensitivity of CHO cells to physical and chemical stresses. Shear stresses inside the growth chamber will have to be reduced by three orders of magnitude. Moreover, the long doubling time of CHO cells requires a 2 weeks long culture. In a high surface to volume ratio micro-bioreactor, evaporation becomes a major problem. Contamination control is also vital for CHO cultures. In addition, the offline sampling volume required for validation necessitates a doubling of the working volume to 2mL. The newly designed Resistive Evaporation Compensated Actuated (RECA) micro-bioreactor is fully characterized in this thesis to ensure that the design meets the physical specifications of the required CHO cell culture conditions. The RECA micro-bioreactor will be tested with industrial recombinant CHO cell lines. This work is done in collaboration with Genzyme, USA and Sanofi-Aventis, Frankfurt. In this thesis, we also propose the use of dielectric spectroscopy electrodes for online cell viability sensing of CHO cells in micro-bioreactors. The electrodes are fabricated on polycarbonate, a biocompatible and optically clear thermoplastic that will be one of the future base material for microfluidic devices which can be rapidly prototyped. To demonstrate the viability of dielectric spectroscopy as an online viability sensor for CHO cells in a micro-bioreactor, the electrodes are used to characterize samples taken daily from a CHO shake flask batch culture without any sample modifications. Two different electrode geometries and correction methods will be compared to find the optimal system for viability measurements in a micro-bioreactor.
by Shireen Goh.
Ph.D.
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Zsirai, Tamas. "Fouling and clogging in hollow fibre membrane bioreactor." Thesis, Cranfield University, 2013. http://dspace.lib.cranfield.ac.uk/handle/1826/8411.
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The sustainability of a large pilot-scale hollow fibre immersed membrane bioreactor (HF iMBR) has been investigated with specific reference to membrane surface fouling and membrane channel clogging. Studies were conducted at normal sludge solids concentration of around 8 g/L and were also extended to concentrations more associated with thickening processes (around 32 g/L). A review of mechanically- moved membranes was conducted with a view to exploring a low energy means of sustaining operation through suppressing clogging. Methods were devised to quantify the amount of clogged solids within the membrane fibre bundle, either through their separation and gravimetric analysis or in-situ gravimetic estimation of the clogged solids without their removal from the membrane HF bundle. Outcomes generally revealed clogging to be as important a contributor to suppression of permeability as fouling, the key differentiator being that chemical cleaning had no sustained impact on permeability recovery when clogging took place. It was further substantiated that the operating permeability of membranes, once they had been clogged, could not be returned to that of the preclogged state despite declogging (i.e. mechanical removal of the solids) followed by the repeated application of chemically-enhanced backwashing. This was attributed to membrane pore plugging. Cont/d.
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DeAbreu, Ricardo. "Facultative Bioreactor Landfill: An Environmental and Geotechnical Study." ScholarWorks@UNO, 2003. http://scholarworks.uno.edu/td/39.
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A relatively new concept of Municipal Solid Waste treatment is known as bioreactor landfill technology. Bioreactor landfills are sanitary landfills that use microbiological processes purposefully to transform and stabilize the biodegradable organic waste constituents in a shorter period of time. One of the most popular types of bioreactor landfills is the landfill with leachate recirculation. However, it is observed that ammonia rapidly accumulates in landfills that recirculate leachate and may be the component that limits the potential to discharge excess leachate to the environment. In the facultative landfill, leachate is nitrified biologically using an on-site treatment plant and converted by denitrifying bacteria to nitrogen gas, a harmless end-product. In this research, three pilot-plant scale lysimeters are used in a comparative evaluation of the effect of recirculating treated and untreated leachate on waste stabilization rates. The three lysimeters are filled with waste prepared with identical composition. One is being operated as a facultative bioreactor landfill with external leachate pre-treatment prior to recirculation, the second is being operated as an anaerobic bioreactor landfill with straight raw leachate recirculation, and the third one is the control unit and operated as a conventional landfill. Apart from environmental restrictions, geotechnical constraints are also imposed on new sanitary landfills. The scarcity of new potential disposal areas imposes higher and higher landfills, in order to utilize the maximum capacity ofthose areas. In this context, the knowledge of the compressibility of waste landfills represents a powerful tool to search for alternatives for optimization of disposal areas and new solid waste disposal technologies. This dissertation deals with and discusses the environmental and geotechnical aspects of municipal solid waste landfills. In the Environmental Engineering area, it compares the quality of the leachate and gas generated in the three lysimeters and discusses the transfer of the technology studied through lysimeters to procedures for full-scale operation. In the geotechnical area, this dissertation discusses the compressibility properties of the waste and provides a state-of-the-art review of MSW compressibility studies. It also evaluates the compressibility of MSW landfills for immediate and long-term settlements and proposes a new model for compressibility of waste landfills.
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Solomon, MS. "Membrane bioreactor production of lignin and manganese peroxidase." Thesis, Cape Technikon, 2001. http://hdl.handle.net/20.500.11838/901.
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Thesis (M.Tech-Chemical Engineering)--Cape Technikon, Cape Town, 2001The white-rot fungus (WRF), Phanerochaete chrysosporium, is a well known microorganism which produces ligninolytic enzymes. These enzymes can play a major role in the bioremediation of a diverse range of environmental aromatic pollutants present in industrial effluents. Bioremediation of aromatic pollutants using ligninolytic enzymes has been extensively researched by academic, industrial and government institutions, and has been shown to have considerable potential for industrial applications. Previously the production of these enzymes was done using batch cultures. However, this resulted in low yields of enzyme production and therefore an alternative method had to be developed. Little success on scale-up and industrialisation of conventional bioreactor systems has been attained due to problems associated with the continuous production of the pollutant degrading enzymes. It was proposed to construct an effective capillary membrane bioreactor, which would provide an ideal growing environment to continuously culture an immobilised biofilm of P; chrysosporium (Strain BKMF-1767) for the continuous production of the ligninolytic enzymes, Lignin(LiP) and Manganese(MnP) Peroridase. A novel membrane gradostat reactor (MGR) was shown to be superior to more conventional systems of laboratory scale enzyme production (Leukes et.al., 1996 and Leukes, 1999). This concept was based on simulating the native state ofthe WRF, which has evolved on a wood-air interface and involved irnmobilisng the fungus onto an externally skinless ultrafiltration membrane. The MGR however, was not subjected to optimisation on a laboratory scale. The gradostat reactor and concept was used in this work and was operated in the deadend filtration mode. The viability of the polysulphone membrane for cultivation of the fungus was investigated. The suitability of the membrane bioreactor for enzyme production was evaluated. The effect of microbial growth on membrane pressure and permeability was monitored. A possible procedure for scaling up from a single fibre membrane bioreactor to a multi-capillary system was evaluated. Results indicated that the polysulphone membrane was ideal for the cultivation of P chrysosporium, as the micro-organism was successfully immobi1ised in the macrovoids of the membrane resulting in uniform biofilm growth along the outside of the membrane. The production of Lignin and Manganese Peroxidase was demonstrated. The enzyme was secreted and then transported into the permeate without a rapid decline in activity. Growth within the relatively confined macrovoids of the membrane contributed to the loss of membrane permeability. A modified Bruining Model was successfully applied in the prediction of pressure and permeability along the membrane The study also evaluated the effect of potential1y important parameters on the production of the enzymes within the membrane bioreactor. These parameters include air flow (Ch concentration), temperature, nutrient flow, relative redox potential and nutrient concentrations A sensitivity analyses was performed on temperature and Ch concentration. The bioreactor was exposed to normal room temperature and a controlled temperature at 37°C. The reactors were then exposed to different O2 concentration between 21% and 99"10. It was found that the optimum temperature fur enzymes production is 3TJC. When oxygen was used instead of air, there was an increase in enzyme activity. From the results obtained, it was clear that unique culture conditions are required for the production of LiP and MnP from Phanerochaete chrysosporium. These culture conditions are essential fur the optimisation and stability of the bioreactor.
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Singh, Shailendra. "Methodology for Membrane Fabric Selection for Pilot-Bioreactor." Ohio University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1313078841.
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RAO, PRASANNA. "TREATMENT OF ACID MINE DRAINAGE USING MEMBRANE BIOREACTOR." University of Cincinnati / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1006887417.
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Trzcinski, Antoine Prandota. "Anaerobic membrane bioreactor technology for solid waste stabilization." Thesis, Imperial College London, 2009. http://hdl.handle.net/10044/1/4358.
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In this study, a simulated Organic Fraction of Municipal Solid Waste (OFMSW) was treated inan anaerobic two-stage membrane process. The OFMSW feedstock was fed to a ten litre hydrolyticreactor (HR) where solid and liquid fractions were separated by a coarse mesh, whilethe leachate was fed to a three litre submerged anaerobic membrane bioreactor (SAMBR) within-situ membrane cleaning by biogas sparging beneath a flat sheet Kubota membrane. Theaim was to develop and optimize this two-stage process where the use of a membrane in bothreactors to uncouple the Solid and Liquid Retention Times (SRT and HRT) would allow us toimprove the current performances obtained with single stage designs. The Denaturing GradientGel Electrophoresis (DGGE) technique was used to monitor the microbial population in the reactorsand have a better understanding of the archaeal and bacterial distribution in a two-stageprocess. It was found that meshes with pore sizes of 10 microns and 150 microns were inappropriateto uncouple the SRT and HRT in the HR. In the former case, the mesh became clogged, whilein the latter case, the large pore size resulted in high levels of suspended solids in the leachatethat built up in the SAMBR. The most important parameter for Volatile Solids (VS) removal in theHR was the SRT. Maximum VS removals of 70-75% could be achieved when the SRT was equalto or greater than 50-60 days. This was achieved at a HRT of 9-12 days and an Organic LoadingRate (OLR) of 4-5 g VS.l-1.day-1.Increasing the SRT to beyond 100 days did not significantlyincrease the VS removal in the HR. However, at an OLR of 10 g VS.l-1.day-1 in the HR the SRThad to be reduced due to a build up of TS in the HR that impeded the stirring. Below 20 daysSRT, the VS removal reduced to between 30 and 40%. With kitchen waste as its main substrate,however, an OLR of 10 g VS.l-1.day-1 was achieved with 81% VS removal at 23 days SRT and1.8 days HRT.The SAMBR was found to remain stable at an OLR up to 19.8 g COD.l-1.day-1 at a HRT of0.4 day and at a SRT greater than 300 days, while the COD removal was 95%. However, theperformance at such low HRTs was not sustainable due to membrane flux limitations whenthe Mixed Liquor Total Suspended Solids (MLTSS) went beyond 20 g.l-1 due to an increase inviscosity and inorganics concentration. At 35 ?C the SAMBR was found to be stable (SCODremoval 95%) at SRTs down to 45 days and at a minimum HRT of 3.9 days. The SAMBRcould achieve 90% COD removal at 22 ?C at an OLR of 13.4 g COD.l-1.day-1 and 1.1 days HRT(SRT = 300 days).The DGGE technique was used to monitor the archaeal and bacterial diversity and evolutionin the HR and SAMBR with varying SRTs, HRTs, OLRs and temperatures in the biofilm andin suspension. Overall, it was found that stable operation and high COD removal correlatedwith a high bacterial diversity, while at the same time very few species (2-4) were dominant. Only a few dominant archaeal species were sufficient to keep low VFA concentrations in theSAMBR at 35 ?C, but not at ambient temperatures. It was found that some of the dominantspecies in the HR were hydrogenotrophic Archaea such as Methanobacterium formicicum andMethanobrevibacter while the other dominant species were from the genus Methanosarcinaor Methanosaeta. The presence of hydrogenotrophic species in the HR could be fostered byreinoculating the HR with excess sludge from the SAMBR when the SRT of the SAMBR wasgreater than 45 days. Among the bacterial species Ruminococcus flavefaciens, Spirochaeta,Sphingobacteriales, Hydrogenophaga, Ralstonia, Prevotella and Smithella were associated withgood reactor performances.
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Grandclement, Camille. "Degradation of organic micropollutants using a hybrid bioreactor." Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0354/document.
Full textAbstract:
La présence de micropolluants organiques dans l’environnement et notamment le milieu aquatique, est devenue une préoccupation grandissante au cours des années. En effet, les micropolluants sont éliminés de façon variable par les différents systèmes de traitement des eaux. Ainsi, les stations d’épuration constituent une voie majeure de dissémination de ces composés dans l’environnement. Ces substances chimiques doivent être suivis et traités car elles peuvent avoir des effets indésirables sur les organismes une fois rejetées dans l’environnement. La biodégradation étant un des mécanismes de transformation dominant pour les micropolluants, les procédés biologiques, et notamment les procédés hybrides (biomasse libre et fixée), semblent pertinents pour les éliminer efficacement. Dans ce travail, nous nous sommes focalisés sur la biodégradation de la carbamazépine (CBZ), du diclofénac (DCF) et du diuron (DIU) par des microorganismes sélectionnés en utilisant un bioréacteur hybride. La méthodologie proposée a reposé sur la mise en place de tests de biodégradation en batch afin de sélectionner des microorganismes pertinents pour la dégradation des molécules cibles, avant de travailler avec un bioréacteur hybride. Les souches sélectionnées ont permis de dégrader complètement le DCF en moins de 24 heures et ont montré des résultats encourageants en 72 heures pour les autres composés. L’efficacité des souches a ensuite été évaluée sur des bioréacteurs hybrides prototypes sous différentes conditions. Bien que l’élimination du DCF ait été importante en conditions stériles, la cinétique observée était plus faible. La CBZ et le DIU ont quant à eux été faiblement éliminésThe occurrence of organic micropollutants in the environment and notably in the aquatic bodies has become a growing concern over the years. Indeed, micropollutants are variably eliminated with different wastewater treatment systems. Thus, wastewater treatment plants represent the main transfer pathways for micropollutants to enter the environment. Among these chemical substances present in the environment at very low concentrations, pharmaceutical compounds and pesticides are of a great concern because of their potential adverse effects to ecosystems. Since biodegradation is one of the predominant transformation pathway for micropollutants, biological processes and notably hybrid processes (combining free and supported biomasses), seem relevant to remove them efficiently. In this work, our interest focuses on the biodegradation of carbamazepine, diclofenac, and diuron by selected microorganisms using a hybrid bioreactor. The methodology developed in this work consisted in the implementation of batch degradation experiments in order to select efficient microorganisms able to break down target molecules, before evaluating their efficiency using a hybrid bioreactor. The selected strains allowed degrading completely diclofenac by a co-metabolism process in less than 24 hours, and showed encouraging results in 72 hours for the other compounds. Then, the efficiency of selected strains has been evaluated using hybrid bioreactors prototypes under different conditions. Even though the removal of diclofenac was very high under sterile conditions, the observed kinetic was lower. Carbamazepine and diuron showed low removal
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Pattanayak, Soubhagya Kumar. "Exploration of fouling propensity in an anaerobic membrane bioreactor treating municipal wastewater and comparison to that of an aerobic membrane bioreactor." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/32050.
Full textAbstract:
Anaerobic biodegradation is a successful technology that has been used in
industrial, food processing, and agricultural wastewater treatment for many decades. The
operational costs associated with anaerobic systems are typically lower than with aerobic
systems and anaerobic systems also generate less waste sludge. However, the application
of anaerobic treatment systems is limited for low strength wastewaters in colder climates.
In colder climates, the biomass growth yield and the growth rate are relatively low,
resulting in a low net biomass production. To maintain adequate biomass concentration in
an anaerobic bioreactor, membrane modules can be coupled to the reactor to effectively
treat low strength wastewater in colder climates. One of the important advantages of the
membrane bioreactors (MBRs) is that the membrane component of the system can retain
virtually all of the biomass within the bioreactor. Membrane units in an anaerobic MBR
can operate either as external units or as submerged units, depending on the requirements
of the process. Currently, the application of submerged AnMBRs is limited as compared
to external AnMBRs. However, the vacuum-driven submerged membrane process shows
a lot of promise as compared to external membrane processes. This is because high
energy consumption is one of the biggest limiting factors in external membranes. Also,
the use of head space gas for reducing fouling in submerged anaerobic membranes can be
a very successful technology in limiting energy consumption in bioreactors. However, the
widespread use of membrane technology has been limited due to the fouling of the
membrane fibers. Membrane fouling is an inherent problem with membrane processes,
which not only affects the long term operational stability, but also leads to significant
operational costs due to increased membrane replacement frequency and added energy
consumption. Therefore, a considerable amount of research and engineering effort has
been devoted to understanding the mechanisms of membrane fouling and to work out
fouling prevention and control strategies.
The broad objective of the present study was (1) to assess the treatment
performance of a submerged membrane AnMBR treating low strength municipal wastewater at an ambient temperature and (2) to identify and characterize the fouling
mechanism in the AnMBR.
The anaerobic process was effective in removing chemical oxygen demand
(COD) and volatile fatty acid (VFA) from the effluent VFA removal was essentially
complete and 80% COD removal was achieved under acetate-supplemented conditions.
Nonetheless, high concentration of effluent COD (i.e. 72 mg/L) indicated that aerobic
post treatment is needed to achieve secondary quality effluent.
On-line filtration studies were conducted simultaneously on both the anaerobic
membrane and the aerobic membrane of membrane enhanced biological phosphorus
removal (MEBPR) process. The on-line tests were conducted to compare the fouling
mechanism in the anaerobic membrane process and the aerobic membrane process. The
results from energy dispersive X-ray (EDX) analysis suggest that inorganic materials
were not the prominent foulants in the AnMBR. Also, scanning electron microscopy
(SEM) analysis indicated that very little microbial colonization was found in the
anaerobic membranes.
Mixed liquor characterization tests were conducted to verify the role of extracellular
polymeric substances (EPS) on membrane fouling. The tests concluded that the
total bound EPS concentration was higher in the aerobic mixed liquor and the total
soluble EPS concentration was higher in the anaerobic mixed liquor. The high soluble
EPS concentration was probably the reason for rapid fouling of anaerobic membranes. In
addition, the higher SRT in the case of the anaerobic membrane bioreactor might be
responsible for the high soluble EPS production observed in some studies.Applied Science, Faculty of
Civil Engineering, Department of
Graduate
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Abegglen, Christian Konrad. "Membrane bioreactor technology for decentralized wastewater treatment and reuse /." Zürich : ETH, 2008. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=17998.
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Zhang, Zhigen. "Bioreactor studies of heterologous protein production by recombinant yeast." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq21404.pdf.
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Puzanov, Taya. "Continuous production of lactic acid in a membrane bioreactor." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0019/MQ49724.pdf.
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