Engineering Commons^™

The Effect Of Steam Explosion On Lipids Extraction From Microalgae And Derivation Of Pectin Films From Waste Culture, Shahil Chhiba

Electronic Thesis and Dissertation Repository

The objective of this study was to investigate the properties of sustainable replacements for plastics and diesel fuel, derived from microalgae (Chlorella vulgaris) subjected to steam explosion. During the process, oven temperatures of up to 500 °C were reached, with the experiments left for different times after reaching their maximum internal temperature. Lipids were extracted from algal cultures using a modified Folch method. The waste microalgae were combined with pectin and glycerol to form biodegradable films, and their solubilities and tensile strengths were measured. The highest yield was 124 mg lipids/g microalgae from 400 °C steam explosion for …

Investigation Of Foam Based Photobioreactor For The Cultivation Of Chlorella Vulgaris Cpcc 90, Anuradha Krishnan

Electronic Thesis and Dissertation Repository

Today, microalgae are cultured in large-scale systems such as open ponds and photobioreactors. Open pond systems, while not expensive, have disadvantages, including contamination and high water consumption, resulting in increased cost of harvesting and quick evaporation. Photobioreactors overcome some of the challenges of an open pond system. However, the reactor setup, operation, and microalgae harvesting are relatively more expensive when compared to conventional techniques. In this study, a novel foam-based photobioreactor system was applied to investigate both the cultivation and harvest of microalgae using different surfactant agents, i.e., rhamnolipids, Bovine Serum Albumin (BSA), saponin, and the commercial surfactant Pluronic f127 …

Investigation Of Heavy Metal Removal From Synthetic Desalter Effluent Using A Two-Step Approach By Micellar-Enhanced Ultrafiltration And Microbial Fuel Cell, Carlos Munoz-Cupa

Electronic Thesis and Dissertation Repository

Heavy metals in wastewater streams negatively affect the environment due to their high toxicity. Non-conventional heavy metal removal methods show higher efficiencies for the remediation of these pollutants. In this investigation, a two-step approach using micellar-enhanced ultrafiltration (MEUF) and microbial fuel cell (MFC) was investigated to remove copper, manganese, and zinc from a synthetic salt wastewater containing magnesium, sodium, and phenol. This synthetic solution was used to simulate refinery wastewater streams such as desalter effluent. The study was carried out in three phases. In the first phase, a flat plate polyether sulfone membrane was investigated for the MEUF process with …

Novel Fed-Batch Process With In-Situ Product Recovery For Glycerol Fermentation To Butanol Using Clostridium Pasteurianum, Ammi Jani

Electronic Thesis and Dissertation Repository

Butanol, a next-generation biofuel, can be produced by fermenting glycerol using Clostridium pasteurianum. To address product inhibition, an integrated system that combined a fed-batch process with pervaporation was assessed against conventional batch and fed-batch fermentations. This study showed that with the novel process configuration, the productive fermentation time could be extended, translating to a 2.4-fold and 1.9-fold increase in butanol production relative to baseline fed-batch and batch operation, respectively. Further, it was demonstrated that butanol concentrations were able to be maintained below inhibitory levels throughout the fermentation. Despite this outcome, metabolic oscillations were revealed, indicating instability in the process. The …

Overcoming Technological Challenges For The Commercialization Of The Circulating Fluidized Bed Bioreactor For Municipal Wastewater Treatment, Michael J. Nelson

Electronic Thesis and Dissertation Repository

The fluidized bed bioreactor as an attached growth wastewater treatment process has demonstrated advantages over suspended growth processes for municipal wastewater treatment applications. However, previous studies have also demonstrated potentially serious disadvantages in terms of energy consumption and maximum reactor size of high flow applications.

In this work, a cost analysis using the CapdetWorks, supplemented by calibrated model data taken from GPS-X was performed to determine the cost effectiveness of the circulating fluidized bed bioreactor (CFBBR). This study demonstrated that the CFBBR is most cost competitive at low flow below 5 MGD. A 10%-20% reduction in net present values on …

Co2 Derived Carbon Capture Using Microalgae In A Photobiocrec Unit, Maureen D. Cordoba Perez

Electronic Thesis and Dissertation Repository

Microalgae has the potential to contribute to carbon dioxide capture, resulting in the production of alternative fuels and valuable chemical products. To accomplish this, high-efficiency photobioreactors must be conceptualized, designed, and established, in order to achieve high inorganic carbon conversion, superior light utilization, and unique fluid dynamics.

In this PhD Dissertation, experiments with Chlorella vulgaris were carried out, in a 0.175L especially designed PhotoBioCREC unit, under controlled radiation and high mixing conditions. This unique design involves 1 mm-2 mm alumina particles, which keep photoreactor walls always clean, without compromising photon transmittance. Sodium bicarbonate (NaHCO₃) was supplied as the …

Growth Viability Assay Assessment For Disinfectant Screening, Paavana Jayaram

Electronic Thesis and Dissertation Repository

Disinfectant screening is an important step for manufacturing and approval of disinfectants. Screening helps identify the effectiveness, target microbe, minimum inhibitory concentration, and contact time. A standard screening test must be able to assess these parameters effectively over a broad range of formulations and microbes. Currently, there is no unified method to analyze disinfectants, a standard test is selected based on the application. This project aimed to identify a standard method that can be used over a broad range of microbes irrespective of disinfectant composition. Microbicidal activity of Hydrogen peroxide and Quaternary ammonium-based disinfectants was evaluated by Fluorescein diacetate (FDA), …

Development Of A Recombinant Brewing Yeast To Produce Beer From Hemp Extract (Cannabis Sativa L.), Mehmet Ugur Gulmen

Electronic Thesis and Dissertation Repository

The Cannabis industry is a rapidly-growing market in Canada. With the legalization of edible products in 2019, many cannabis-derived candies, baked goods, beverages appeared on shelves. Cannabis beer can be brewed by replacing barley with pretreated cannabis plant. However, using a traditional brewing yeast to brew cannabis beer will result in incomplete fermentation which will affect the beer’s composition and flavour because traditional brewing yeasts are not able to utilize xylose which is an abundant carbohydrate in lignocellulosic extracts. Using a recombinant strain of a brewing yeast and a xylose-fermenting yeast can overcome this issue. The work presented in this …

Bridging Thermochemical And Biochemical Conversion: Impact Of Biochar Addition On The Anaerobic Digestion Of Aqueous Pyrolysis Condensate, Neha Batta

Electronic Thesis and Dissertation Repository

Profitable treatment of low value waste biomass is one of the biggest challenges of the industry. Where most of the current treatment strategies, such as pyrolysis, are efficient in complete breakdown of hard to synthesize, low value waste biomass such as lignocellulosic wastes, it leads to the generation of secondary waste thereby compromising its efficiency. The aim of this research is to utilize the aqueous pyrolysis condensate as a feedstock for anaerobic digestion, previously adapting the microbial consortia to the acidity and other potential organic inhibitors present in the APC, to produce energy in the form of biogas following the …

Value-Added Lipids Extraction From Wet Microalgae Using Ionic Liquids, Yujie Zhang

Electronic Thesis and Dissertation Repository

Microalgae have gained interest as sources of renewable lipids in the biofuel sector due to their ability to sequester carbon dioxide into triacylglycerol (TAG), a biodiesel feedstock. However, industrial-scale production of microalgae exclusively for fuel production is limited by technical and economic challenges. Some marine microalgae can accumulate large amounts of polyunsaturated fatty acids (PUFAs) such as docosahexaenoic acid (DHA) and other unsaturated fatty acids, which are high-value compounds linked to the prevention of various cardiovascular diseases. This thesis therefore examines the extraction of lipids and DHA from two microorganisms (Chlorella vulgaris, a model organism for lipid production, …

Improved Fermentation Design And Screening Devices For Biobutanol Production, Garret Christopher Munch

Electronic Thesis and Dissertation Repository

A worldwide increase in demand for renewable fuels has revived interest in fermentatively produced butanol. However, butanol fermentation suffers from low product yields and productivity. The work presented in this thesis addresses part of these research and development needs at three levels: innovative fermentation process design; genetic manipulation for strain enhancement; and the development of a new tool for anaerobic process characterization and optimization.

Product yield could be increased through traditional fermentation engineering. Co-fermentation of butyric acid with glycerol increased the butanol yield from 0.45 mol/mol (mols C in butanol / mol C in substrates) to 0.51 mol/mol. In building …

Design, Fabrication And Applications Of Efficient Conductive Polymers For Photocatalytic Antimicrobials, Chunbo Liu

Electronic Thesis and Dissertation Repository

Designing new antimicrobial surfaces which are effective under visible light irradiation without leaching toxic ions is a current challenge for effective disinfection. A new polymeric system poly[2,11’-thiophene-ethylene-thiophene-alt-2,5-(3-carboxyl) -thiophene] (PTET-T- COOH) with broad light absorption was synthesized. Its photocatalytic disinfection performance against staphylococcus aureus (S. aureus) and streptococcus suis (S. suis) was evaluated, showing over 99.999% inactivation (higher than 5-log inactivation) in 2 h for both bacteria, under visible light irradiation at a low concentration of PTET-T-COOH (0.1 mg/mL). In addition, a PTET-T-COOH/polyurethane (PU) polymeric coating was designed and fabricated. Chemical attachment was confirmed between PTET-T-COOH and PU using various thermophysical …

Bioluminescence Resonance Energy Transfer (Bret) - Based Nanostructured Biosensor For Detection Of Glucose, Eugene Hwang

Electronic Thesis and Dissertation Repository

Bioluminescence resonance energy transfer (BRET) is a distance dependent, non-radiative energy transfer, which uses a bioluminescent protein to excite an acceptor through resonance energy transfer. In this thesis, BRET technology is incorporated into a sensor comprised of a recombinant protein and quantum dots. The recombinant protein, which includes the bioluminescent protein, Renilla luciferase (Rluc), is used as the donor molecule and cadmium tellurium quantum dots as the acceptor molecules. Separating the donor-acceptor pair is a recombinant protein, glucose binding protein, which changes conformation upon binding glucose and brings the pair closer together, thus allowing BRET to occur. Optimization of the …

Bioremediation Of Refinery Desalter Effluent Using Debaryomyces Hansenii And Parachlorella Kessleri, Leila Azimian

Electronic Thesis and Dissertation Repository

Crude oil desalting operations produce an effluent stream which is challenging to treat due to its salt, heavy metal and hydrocarbon content. Consequently, desalter effluent (DE) is usually diluted into other effluent streams and sent to conventional wastewater treatment plants which may lead to upsets the plant operation.

In this study, a novel microbial approach was applied which investigated DE treatment using halotolerant yeast Debaryomyces hansenii (LAF-3 10 U) or the environmentally robust micro-algae Parachlorella kessleri strain CPCC 266. The effect of these two different approaches on both synthetic and actual DE was investigated in both batch and/or continuous mode. …

Evaluation Of Biohydrogen Production From Co-Fermentation Of Carbohydrates And Proteins, Emmanuel Andrew Tepari Jr,

Electronic Thesis and Dissertation Repository

The aim of this study was to examine volatile fatty acid (VFA) production from a proteinaceous substrate, bovine serum albumin (BSA) for a pH range of 5 – 9, and to further assess its impact on hydrogen production in a co-fermentation process using starch and BSA at different ratios. The established optimum conditions for VFA production from BSA were an initial pH of 8, incubation time of 3 days and an operating temperature of 37 ℃. Using these fermentation conditions, the stoichiometric reactions that describe the anaerobic degradation of BSA were investigated. A methodology that describes organic acid production from …

Characterization Of Tetrazolium Salts And Formazans Using Computational Chemistry For Radiochromic Dosimetry, Teshome G. Bedada

Electronic Thesis and Dissertation Repository

Computational chemistry is a powerful tool to model different materials and predict their physical and chemical properties. The goal of this thesis was to apply different computational chemistry tools to model the properties of two classes of closely related organic compounds: formazans and tetrazolium salts for ionizing radiation dosimetry in water-based gels, whereby the absorbed dose is registered by optical detection of formazan formation from tetrazolium salts. The structural parameters of phenyl and benzothiazolyl-substituted tetrazolium salts and formazans were computed using the APFD density functional theory (DFT) model and 6-311+G(2d,p) basis set. Conformational searching of stereoisomers (TSCA and TATA structures) …

Highly Efficient Depolymerization Of Kraft Lignin (Kl) And Hydrolysis Lignin (Hl) Via Hydrolysis And Oxidation, Zaid Ahmad

Electronic Thesis and Dissertation Repository

Due to dwindling fossil resources, climate change and other environmental concerns as well as the toxicity of certain products derived from petroleum resources, there is a growing interest in exploring and utilizing the abundant biomass resources as alternative feedstocks for the production of bio-based chemicals and materials. Biomass is composed of three main macromolecules, namely: cellulose, hemicellulose, and lignin. Even though most of the initial work relating to the valorization of biomass was focused on the carbohydrate components (cellulose and hemicellulose), in the last ten years, lignin, an aromatic biopolymer, has been receiving increasingly more attention. In particular, various routes …

Anaerobic Digestion Of Aqueous Pyrolysis Condensate, Connie Wen

Electronic Thesis and Dissertation Repository

Lignocellulosic material can be subjected to pyrolysis to yield pyrolysis liquid, biochar, and gas. The pyrolysis liquid resulting from the condensation of vapours can be separated into a rich organic condensate and an acidic “aqueous pyrolysis condensate” (APC) which may be considered a waste. The target of this research is subjecting APC to anaerobic digestion to produce biogas that can be energy purposed, and to reduce the organic load of APC to acceptable levels for possible disposal. From this study, it was found that without any treatment, the inoculum requires 50 to 60 days of adaptation period to reduce the …

Maintaining And Controlling An Extrinsic Biofilm For Pathogen Removal In Dental Unit Water Lines, Bilal B. Al-Bataina

Electronic Thesis and Dissertation Repository

The control of biofilm formation is a major concern for industrial, environmental, and public health. Undesirable biofilms can harbor different disease-causing pathogens and shorten the operational life of different equipment. On the other hand, beneficial biofilms are also used in various applications and managing its growth and activity can be desirable. Killing the biofilm does not usually incorporate the removal of the dead biofilm structure that is adhered to the surface. Therefore, the aim of this thesis is to control biofilm formation; to be able to remove, inhibit, and enhance biofilm formation. This thesis investigated the use of norspermidine, D-amino …

Biobutanol Production From Cellulosic And Sugar-Based Feedstock From The Corn Plant, Reyna Gomez-Flores

Electronic Thesis and Dissertation Repository

In this thesis, biobutanol production by biological fermentation was investigated from the corn plant, integrating two approaches. The first one was to utilize corn cobs, a cellulosic-based material. The second, using a new sugar-based material, sugarcorn juice. Utilizing suitable Clostridia strains for each substrate, these approaches converged into a biorefinery concept to produce renewable biofuels in Ontario, Canada. The corn cob pretreatment was carried out by a dilute acid method resulting in temperature as the variable with most significant effect towards glucose liberation. The enzymatic hydrolysis was performed utilizing a very low concentration of an enzymatic stock solution with approximately …

Hydrothermal Liquefaction Of Microalgae For The Production Of Bio-Crude Oil, Yulin Hu

Electronic Thesis and Dissertation Repository

Due to the depletion of fossil fuels and climate change, extensive research has performed towards renewable energy production from microalgal biomass. Microalgae have several inherent benefits, such as high photosynthetic efficiencies, fast growth rates, and high lipid contents. In addition, microalgae can be cultivated in the non-arable lands (e.g., saline and waste water), thereby no competition with food crops production.

Transesterification is the one of commonly used technologies for converting microalgae into liquid bio-fuels (i.e., biodiesel). Normally, an energy-intensive drying step is required in the transesterification treatment, which accounts for nearly half of the energy input. Hence, if “wet” microalgal …

Covalently Crosslinked Organic/Inorganic Hybrid Biomaterials For Bone Tissue Engineering Applications, Dibakar Mondal

Electronic Thesis and Dissertation Repository

Scaffolds are key components for bone tissue engineering and regeneration. They guide new bone formation by mimicking bone extracellular matrix for cell recruitment and proliferation. Ideally, scaffolds for bone tissue engineering need to be osteoconductive, osteoinductive, porous, degradable and mechanically competent. As a single material can not provide all these requirements, composites of several biomaterials are viable solutions to combine various properties. However, conventional composites fail to fulfil these requirements due to their distinct phases at the microscopic level. Organic/inorganic (O/I) class II hybrid biomaterials, where the organic and inorganic phases are chemically crosslinked on a molecular scale, hence the …

Bacterial Cellulose Nanocrystals: Production And Application, Isabela Reiniati

Electronic Thesis and Dissertation Repository

The aims of this study were to investigate the effect of culture conditions on the production of bacterial cellulose (BC) by Komagataeibacter xylinus (K. xylinus), to assess the feasibility of tailoring the surface properties of bacterial cellulose nanocrystals (BCNs) through the culture conditions, and to use the BCNs in an aqueous system for drug adsorption application. BC fibers production improved with increased agitation rates in a stirred tank bioreactor resulting in yields of 0.54 and 1.13 g of BC per litre at agitation rates of 500 rpm and 700 rpm, respectively. Separation and purification of bacterial cellulose were achieved …

Bubble-Induced Inverse Gas-Liquid-Solid Fluidized Bed, Xiliang Sun

Electronic Thesis and Dissertation Repository

Gas-liquid-solid fluidized beds have been widely applied in wastewater treatment, however, the current method of wastewater process has several limitations. Hence, an improved method is in demand. A 3.5 height and 0.1534m inner diameter column was used to study the hydrodynamic characteristics of a bubble-induced three-phase inverse fluidized bed. Air, water and three types of low-density particles were employed as gas, liquid and solid phases.

The hydrodynamic properties in the bubble-induced three-phase fluidized bed were investigated to provide the basic information for the industrial process, such as flow regime, bed expansion ratio and phase holdups. A flow regime map containing …

Fabrication And Characterization Of Hybrid Nanocomposites By Matrix Assisted Pulsed Laser Evaporation, Songlin Yang

Electronic Thesis and Dissertation Repository

Different methods have been applied to deposit hybrid nanocomposites which can be applied in various fields due to their light weight and multifunctional properties. Here, matrix assisted pulsed laser evaporation (MAPLE) equipment with 532 nm Nd:YAG laser is applied to fabricate three types of hybrid nanocomposites on different substrates.

Chemical synthesized FeCo nanoparticles were deposited on graphene sheets by MAPLE technique (laser fluence: 300 mJ/cm²). The effects of deposition time (t) on particle amount, shape and size have been investigated. Yttrium barium copper oxide (YBCO) materials are one type of high-temperature superconductive materials and …

Nanostructured Biosensor For Tear Glucose Detection Based On Bioluminescence Resonance Energy Transfer (Bret) Mechanism., Denghuang Zhan

Electronic Thesis and Dissertation Repository

Bioluminescence Resonance Energy Transfer (BRET), a sensitive, non-destructive and self-illuminated method, has been now commonly used to test protein interactions. Here, we describe a BRET sensor for non-invasively detecting glucose molecules. The sensor is made by the bioconjugation of quantum dots and recombinant protein. The recombinant protein contains the bacterial glucose binding protein (GBP) and a bioluminescent protein, Renilla luciferase (Rluc), used as the donor with the emission peak at 470 nm, which is able to excite the acceptor of BRET sensor made of cadmium tellurium quantum dots ( CdTe QDs) with the emission peak at 570 nm. The distance …

Genetic Engineering Studies Of Escherichia Coli And Microalgae For Expression Of Hydrolytic Enzymes And Development Of High Throughput Screening Technique, Shreyas S. Yedahalli

Electronic Thesis and Dissertation Repository

The field of biochemical engineering has made substantial progress through major advances in genetic and metabolic engineering with applications in various sectors such as energy, food science, pharmaceuticals, etc. The hosts used for this work are constantly broadening. A host particularly important for energy applications are microalgae. The potential to enhance microalgae genetically for energy applications is not well explored and was therefore investigated in this thesis. Non-photosynthetic micro-organisms and photosynthetic microalgae offer a potential approach to enhance sustainable biochemical production. In this study expression vectors for Escherichia coli (E. coli) and Chlorella vulgaris (C. vulgaris) …

Investigation Of Lutein Production And Recovery From Chlorella Vulgaris Using Phototrophic Cultivation, Mengyue Gong

Electronic Thesis and Dissertation Repository

Microalgae have been recognized as a natural reservoir of the valuable commercial carotenoid lutein due to its high lutein content and fast growth cycle. However, the production of lutein from microalgal sources is not yet sufficiently cost-effective to compete with traditional marigold flower-based processing (Park et al., 2015). This thesis aims to investigate the factors affecting lutein production and recovery from microalgae using a phototrophic cultivation mode.

The closed photobioreactors can offer controlled conditions for faster microalgae growth. A coiled tubular tree photobioreactor (CTPBR) design was first investigated for cultivating the cold tolerant microalgae, Chlorella vulgaris UTEX 265, under various …

Bioethanol Production Using Saccharomyces Cerevisae Cultivated In Sugarcorn Juice, Thirumalai Nambi Thiruvengadathan

Electronic Thesis and Dissertation Repository

For the first time, juice extracted from sugarcorn, a new Canadian energy crop, was used for bioethanol production. Physical and chemical characteristics of sugarcorn juice (SCJ) were determined. SCJ contained a maximum of 145 g/L of carbohydrates, with sucrose, glucose and fructose together contributing 80%. Effect of autoclaving and carbon filtration on juice sugars were investigated.

Shake flask fermentations using Saccharomyces cerevisiae grown in yeast extract supplemented SCJ produced a maximum of 45.6 g/L ethanol in 72 h. Bioreactor studies using un-supplemented SCJ achieved 40 g/L ethanol in 26 h, yielding a maximum of 0.46 g ethanol/g fermentable sugars, representing …

Magnetic Stimulation On The Growth Of The Microalga Nannochloropsis Oculata, Manuella Oliveira

Electronic Thesis and Dissertation Repository

Fossil fuels, our principal sources of energy supply, are non-renewable and research is needed on alternatives that are renewable and potentially more environmentally friendly. Microalgae have been investigated as a future feedstock alternative to petroleum but the technology is still expensive and improvements are needed. Reduction in costs might be achieved by increasing algal biomass and lipid productivity. The lipids can be used to produce biofuels such as biodiesel and biojet fuel. The marine microalga Nannochloropsis oculata grows well and can accumulate high lipid content. In this study, the effects of static magnetic field stimulation (SMF) of 0 (control), 5, …