In a society where equality is sought as the norm, occupational gender representation is still skewed in some disciplines. One field where gender equality in representation has not yet been achieved is engineering, whether in college or at the professional level. This imbalance is not only a potentially vicious cycle...
Industrial waste heat composed of saturated liquid water can be redirected to charge a thermochemical energy storage (TCES) system. This energy can be stored long-term in the inherently energy-dense chemical bonds and used for space heating. Initial reactor scale cycling experiments were conducted in tandem with TCES material improvements. Hydration...
This work focuses primarily the development of methods for imaging microbial biofilms in opaque porous media using x-ray computed microtomography (CT). Two methods for evaluating biofilms in porous media are presented. The first focuses on the addition of silver-coated, hollow glass microspheres to a biofilm-containing micro-model. The silver-coated microspheres affix...
The integration of low-pressure membrane filtration and aerobic granular sludge (AGS) reactor leads to a novel environmental biotechnological process with strong potential to overcome membrane fouling and demonstrate excellent wastewater treatment performance. However, membrane fouling mechanisms in the AGS based membrane bioreactor (MBR) are lack of systematic elaboration. In the...
Trichloroethene (TCE) is a common groundwater contaminant. Bioremediation, or the enhancement of natural microbial processes for the transformation of toxic compounds in soil and groundwater, is an effective solution to this widespread problem. The organisms that transform TCE in the subsurface are sensitive to environmental conditions, especially to the presence...
Gender has been the subject of study in engineering education and science social research for decades. However, little attention has been given to transgender and gender nonconforming (TGNC) experiences or perspectives. The role of cisgender or gender conforming status has not been investigated nor considered in prevailing frameworks of gender...
The ability of Mycobacterium sp. ELW1, a novel microbe capable of alkene oxidation, to co-metabolize phenanthrene (PHE) was studied. ELW1 was able to completely co-metabolize PHE, at different concentrations below its water solubility limit, in an aqueous environment. The alkene monooxygenases in ELW1, used to initiate oxidation of PHE, were...
Carbon tetrachloride (CT) and chloroform (CF) were transformed in batch reactor experiments conducted with anaerobic dechlorinating cultures and supernatant (ADC+S) harvested from continuous flow reactors. The Evanite (EV-5L) and Victoria/Stanford (VS-5L) cultures capable of respiring trichloroethene (TCE), 1,2-cis-dichloroethene (cDCE), and vinyl chloride (VC) to ethene (ETH) were grown in continuous...
Stream chemistry studies conducted in the forested Watershed 1 of the HJ Andrews Experimental Forest show a contribution of CO2 from the hyporheic zone. Hyporheic CO₂ concentrations, measured as pCO₂, have a seasonal trend as well as a responsiveness to storm events. Concentrations are highest at the end of the...
Best Management Practices (BMP) are widely used as a method for stormwater volume control in urban areas to prevent an overload of water on receiving water bodies and treatment facilities. BMPs ability to treat stormwater has gone under critical review in the last few decades, and their performance varies both...
Engineered nanomaterials (ENMs) are small anthropogenic colloids with at least one length dimension <100 nanometers. Due to the nature of their use, ENMs are being increasingly released to the environment. Yet the environmental risks posed by ENMs are unknown due to a variety challenges, including limitations with detecting and quantifying...
The production of titanium dioxide (TiO2) nanoparticles has increased significantly in the past decades, which has generated concern due to their known toxicity in the environment. As a result of the production, use and disposal of productions containing TiO2, TiO2 nanoparticles are often received by wastewater treatment facilities. The adsorption...
This project determined how the presence of environmental biofilms on sand, granular activated carbon and biochar affected the sorption capacity and desorption quantity of copper, zinc, nutrients and organic carbon from stormwater. These contaminants have harmful and toxic environmental impacts on aquatic life, can lead to eutrophication of surface waters,...
Due to the effective antimicrobial properties of silver nanoparticles they represent a significant proportion of all consumer-‐related nanomaterials. The introduction of silver nanoparticles from these products into domestic and industrial wastewater streams poses potential complications for biological treatment systems. A critical component of biological treatment that is extremely sensitive to...
Methanotrophic bacteria are promising means of producing value-added products as they have the ability to transform methane under atmospheric temperature and pressure. Efforts to develop methanotrophs to produce value-added products are hoped to incentivize a decrease in methane flaring operations. The data collected during this study was used to inform...
Geologic CO₂ sequestration is a climate change mitigation strategy that involves the injection of supercritical CO₂ into deep underground rock formations. This thesis focuses on capillary trapping in which capillary forces immobilize CO₂ bubbles at the pore scale. During injection of supercritical CO₂, brine is displaced in what is known...
We do not fully understand reasons behind extinction of populations and species. Consequently, our ability to anticipate extinction (which can be considered a permanent type of an ecological threshold) has remained elusive. In particular, it is not clear how the attributes of episodic disturbance regimes can elicit extinction. In this...
Over the last two decades, urban stormwater management has grown to include green infrastructure, such as bioswales. These systems were primarily designed to mitigate hydraulic peaking during rainstorms but were also found to remove particulate and dissolved contaminants. However, little is known about the fate of these particulate contaminants after...
Several types of channel morphology measurement parameters used to
characterize fish habitat of small streams are refined, developed and evaluated in terms
of their accuracy, precision, and sensitivity to disturbance. Data for 74 stream reaches
in Oregon and Alaska are used in analysis. Over half the reaches are from a...
Natural stream systems contain a variety of flow geometries which contain flow separation, turbulent shear layers, and recirculation zones. This work focuses on streams with dead zones. Characterized by slower flow and recirculation, dead zones are naturally occurring cutouts in stream banks. These dead zones play an important role in...
The purpose of this research was to measure the copper-binding behavior of Dissolved Organic Matter (DOM) contained in Pulp and Paper (P&P) wastewater effluent and evaluate the Biotic Ligand Model’s (BLM) ability to quantify copper speciation in P&P influenced waters. A copper ion selective electrode was used to measure copper...
The production of the fullerene C60 and its emerging applications in consumer
products imply its ultimate release to the environment. Due to the molecule’s relative
novelty, the aqueous characteristics of C60 have not been fully assessed, though it may
potentially harm human or ecological health. C60 is highly insoluble in...
This work is a compilation of problems that deal with multiscale analysis of transport phenomena in environmental systems. A common feature among the problems studied here is the presence of non-negligible microscale structure in various forms. Each problem is approached from the perspective that a macroscopic observable encodes aspects of...
Wastewater treatment plants are considered one of the main sources and reservoirs of antimicrobial resistance (AMR). This study investigated the prevalence of 8 different phenotypes of AMR, multi-drug resistant (MDR), and extended-spectrum beta-lactamases (ESBL) producing E. coli in 17 wastewater treatment plants across Oregon in winter and summer of 2019...
Understanding the transport and retention of radionuclides in the environment is important for protecting freshwater supplies and minimizing impact to biologic systems. Technetium-99 (Tc⁹⁹) is a radionuclide of interest due to its long half-life (2.13 x 10⁵ years) and toxicity. In the form of pertechnetate (TcO₄⁻), Tc is expected to...
Stormwater picks up pollutants as it flows over impervious surfaces before ending up in water resources. Best management practices are implemented to remove pollutants from stormwater. Puralytics manufactures a stormwater treatment product called the LilyPad. The LilyPad consists of a titanium dioxide nanoparticle photocatalyst immobilized on polypropylene substrate. Treatment of...
At the beginning of the COVID-19 pandemic, the world was unprepared for such a massive challenge to global health. Individual testing kits and personal protective equipment were scarce. There were minimal ways to track the rapid spread of the disease, until researchers discovered that SARS-CoV-2, the virus that causes COVID-19,...
Atmospheric carbon reduction is arguably the most crucial facet among efforts to mitigate climate change. The Fifth International Panel of Climate Change report emphasizes a worldwide goal of maintaining global temperature elevation less than 1.5°C above pre-industrial temperatures. This report also acknowledges without the proper utilization of counteractive emission strategies...
Numerous studies have shown that some nanomaterials are highly toxic to aquatic organisms and can potentially disrupt overall community health; however, current methods to evaluate the nanomaterials environmental impacts rarely consider the environmental realism or provide sufficient detail on the impact at the community level. Here we demonstrate three approaches...
Heteroaggregation of nanoparticles with naturally occurring colloids has been shown to be an important process in nanoparticle fate and transport in the aquatic environment. The advent of a functional assay to measure heteroaggregation attachment efficiencies has opened the door for further mechanistic studies. It is well known that natural organic...
Anaerobic ammonium oxidation (anammox) has recently appeared as a promising approach for removing nitrogen from landfill leachates because it requires less oxygen and no organic carbon compared to traditional nitrification-denitrification system, and it produces low sludge volumes, thereby reducing operating and biological sludge disposal costs by over 60%. Anammox bacteria...
Agrivoltaics, which integrates photovoltaic power production with agriculture in the same plot of land, has the potential to reduce land competition and crop irrigation. To optimize agrivoltaic systems for crop growth, energy pathways must be characterized. While solar panels shade the crops, they also emit longwave radiation. At the end...
A dissertation describing the results of a series of greenhouse experiments conducted to better understand phytoremediation in stormwater bioretention systems.
1,4-Dioxane (dioxane) is a probable human carcinogen and is often found comingled with chlorinated aliphatic hydrocarbon (CAH) contamination since dioxane is used as a stabilizer in CAH solutions. Dioxane is miscible in water, has a low K[subscript ow], low H[subscript cc], and is highly recalcitrant in the environment. The presence...
Systems that contain multi-phase flow in porous media are of interest in diverse fields including environmental engineering, hydrogeology, and petroleum engineering etc. One of the main descriptors of multi-phase flow in porous media is the relationship between capillary pressure and fluid saturation. Capillary pressure is inherently a pore-scale variable and...
Engineering practice is aptly described as a unique culture, shaped by a long history of social learning, norms and values. As these systems and values have been constructed to the benefit of white men, it is unsurprising that the study of engineering culture has revealed many structures working against the...
Bioremediation of chlorinated ethenes by the augmentation of contaminated soils with microorganisms is a proposed method of reducing contaminant concentrations in groundwater. To determine the viability of using ELW-1 or R. rhodochrous for groundwater remediation, kinetic analyses of transformation rates must be performed. The focus of this research was to...
The flow of multiple immiscible fluids within a porous medium controls many natural and engineered systems in the environment including: geologic CO2 sequestration, enhanced oil recovery from underground reservoirs, and contaminant remediation of groundwater. The need to understand how fluids are transported and distributed in these processes is important for...
Identifying the inhibition of ammonia oxidizing bacteria (AOB) by emerging organic contaminants is crucial due to the importance of AOB in wastewater treatment, the widespread use of antibacterial agents such as triclosan (TCS) in consumer products, and the sensitivity of N. europaea to inhibitors. Triclosan inhibition of nitrification by AOB...
Despite decades of cleanup efforts, chlorinated solvents are some of the most common groundwater and subsurface contaminants of the industrialized world. These compounds include chlorinated ethenes (CEs) such as trichloroethene (TCE) and chlorinated methanes (CMs) such as carbon tetrachloride (CT). Dehalococcoides mccartyi belongs to a class of microorganisms called organohalide-respiring...
Nanoparticles are becoming increasingly important in numerous technological fields but evidence shows that they can be toxic to many organisms. To predict their fate and transport in the environment, nanoparticle attachment to naturally occurring colloids must be examined. This study investigated citrate-capped gold nanoparticle (Cit-AuNP) heteroaggregation with two model colloids...
Understanding the aggregation behavior of engineered nanomaterials (ENMs) in aqueous environments is essential to understanding their fate, transport, and toxicity. Because naturally occurring colloids will likely be present at much higher concentrations than ENMs in environmental systems, heteroaggregation and attachment with these natural colloids could significantly influence ENM fate and...
Anaerobic digestion is a biological process in which organic matter is decomposed by a community of microbes in the absence of oxygen. The end product of anaerobic digestion is biogas, composed of methane and carbon dioxide, which is often recovered and used to generate energy. Commonly, biogas is not produced...
An important goal of engineering educators is to prepare students to interact and communicate with other professionals, especially other engineers. Object and process scale is a crucial concept that engineers are required to communicate frequently and effectively. The goal of this study is to characterize how engineers communicate scale within...
Women are highly-underrepresented in undergraduate engineering majors, making up just over 15% of students in engineering and computer science at Oregon State University. High school girls' interest in pursuing engineering in college is affected by the way language frames engineering careers. The status-quo engineering frame is made up of terms...
Food waste (FW), brewery waste (BW), and fats, oils, and greases (FOG), are prevalent waste streams in municipalities across the country, particularly in the Pacific Northwest (PNW). Anaerobic digestion (AD), the microbial-mediated transformation of organic waste into methane-rich biogas, offers a sustainable, energy-generating, waste management solution for these wastes. Anaerobic...
Understanding the mechanisms controlling colloid transport and deposition in the vadose zone is an important step in protecting our water resources. Colloid transport in unsaturated porous media was studied using X-Ray Microtomography (XMT), which is a non-destructive imaging technique that provides three-dimensional images at a resolution on the order of...
Anammox (anaerobic ammonium oxidation) bacteria are capable of providing low-cost nitrogen removal for numerous types of wastewaters. However, low growth rates cause long startup-times and inhibition by oxygen and metabolic substrates necessitate close process control to maintain performance. Incorporation of Simultaneous Anammox and Denitrification (SAD) into constructed wetlands could provide...
1,4-dioxane, a probable human carcinogen at low (< 1ppb) concentrations, has emerged as a groundwater contaminant due to its historical use as a stabilizer for the chlorinated solvent 1,1,1-trichloroethane. Aerobic cometabolism, the use of a primary substrate to induce the production of microbial enzymes that fortuitously degrade other compounds, is...
Metal oxide nanoparticles (MONPs) are manufactured at the greatest rate of any class of nanomaterial due to their wide variety of industrial, commercial, and environmental applications. The sustainable use of MONPs requires a balance of careful consideration of their potential negative environmental impacts with the effective exploitation of their unique...
Inadequate access to clean water is an ongoing problem in many developing areas of the world. In developed nations, it is important to plan for access to clean water following natural disasters. In situations without reliable access to electricity and chemical treatment methods, there is a need for an inexpensive...
Stormwater runoff is a significant cause for impairment of many water bodies, a problem that will inevitably escalate due to increasing land-cover change associated with urbanization. The effect of stormwater runoff has spurred legislation and the subsequent development and adoption of Best Management Practices (BMPs) to treat stormwater. This work...
Airports are required by the Federal Aviation Administration to perform deicing of aircraft pavement during icy conditions. Until recently, there were no discharge controls in place and deicing fluid contaminated nearby water bodies from storm water runoff. EPA regulations now require airports to collect the deicing fluid and meet discharge...
Low concentrations of dissolved copper have proven to be harmful to a number of aquatic organisms, with recent research highlighting detrimental effects to endangered salmonid species. Stormwater runoff can represent a significant source of copper to surface waters, necessitating cost-effective alternatives to current stormwater best management practices (BMPs). This study...
Current best management practices (BMPs) for stormwater treatment are not able to adequately remove heavy metals to levels which do not adversely affect aquatic life. Copper is commonly found in highway stormwater runoff, with the primary source being brake pad wear. Copper is of particular concern due to inhibitory effects...
Chlorinated solvents are a class of widespread groundwater contaminants that are toxic, carcinogenic, and difficult to remediate at low concentrations. 1,4-dioxane, a suspected carcinogen, is often a co-contaminant found in mixtures of chlorinated solvent plumes. In-situ bioremediation methods of degrading these chemicals through aerobic cometabolism have shown promise. Permeable Reactive...
A short (approximately 8 minute) video was created to explain key concepts in estuarine flow and numerical modeling of estuaries for high school students. Animation, real picture videography, and numerical model outputs were used to illustrate how scientists use physics and physics models to understand how flow in an estuary...
The epistemic practices that make up engineering are poorly understood and there is a lack of empirical research on this topic. Characterizing the epistemic practices of engineering students, faculty, and professionals is critical to creating effective curriculum that aids in developing student’s epistemic practices. Doing so allows us to better...
Hydrophobic titanium dioxide (TiO2) nanoparticles (NPs) are prevalent in industry and manufacturing. They are known for their white pigmentation, are found in sunscreens, paints, cosmetics, and are frequently used in wastewater treatment. Understanding the physicochemical properties of TiO2 P-25 NPs, such as hydrophobicity, are essential when determining their fate, transport,...
Anaerobic digestion is a microbially mediated process by which organic matter is decomposed in the absence of oxygen. The end products of anaerobic digestion include treated sludge and biogas, a mixture of methane and carbon dioxide, which can be recovered and used for energy generation. The majority of wastewater treatment...
Silver nanoparticles are increasingly being incorporated into consumer products due to their broad-spectrum antimicrobial properties. The resulting influx of silver nanoparticles into wastewater may pose a threat to bacteria involved in biological wastewater treatment. Ammonia-oxidizing bacteria, which convert ammonia to nitrite in the first step of nitrification, are highly sensitive...
A year-long, bench-scale treatability study was performed to assess whether an activated sludge sequencing batch reactor could be used to treat an influent stream of 50/50 (v/v) municipal wastewater and landfill leachate to discharge standards established by the Oregon Department of Environmental Quality. One primary obstacle that was exposed during...
Anaerobic co-digestion of fats, oils, and grease (FOG) for increased methane (CH4)
production has been of increasing interest to municipal wastewater treatment plants
(WWTP) due to the potential economic benefit of using the produced biogas for
cogeneration of energy. FOG loading increase must be done carefully to mitigate the
risk...
Microplastics (MPs) are plastic particles less than 5 mm in diameter. These contaminants are increasingly found in the environment due to increased plastic production, use, and improper disposal. Detecting and measuring these contaminants in the environment has proven difficult, requiring the use of fate and transport models to assess MP...
The fate and transport of engineered nanoparticles (ENPs) such as titanium dioxide (TiO₂) are of concern due to their increasing use in consumer products. Although analytical methods for detection and quantification of ENPs in environmental matrices are being developed, these methods are difficult, time consuming, and not easily validated for...
Removing nitrogen from wastewater is critical to avoid eutrophication of receiving waters. Due to its potential economic benefits, the use of anammox bacteria to remove nitrogen from wastewater is gaining in popularity. Anammox bacteria utilize NO₂- to oxidize NH₄+ to N₂. However, anammox bacteria are sensitive to a wide variety...
The rising demand on freshwater resources emphasizes the benefit of biogeochemical processes that maintain clean water by removing pollutants such as excess nitrogen. The most sensitive step in the removal of nitrogen from waterways is the oxidation of ammonia, a part of nitrification, which is carried out by ammonia oxidizing...
Presented in this report is an investigation of the design, construction, and operation of scaled-up cloth electrode assembly (CEA) air-cathode microbial fuel cells (MFCs). 40 mL MFCs were designed and constructed using either single or double CEAs with carbon cloth electrodes. The MFCs were evaluated using acetate media, municipal wastewater,...
Continuous liquid-liquid two-phase separation is needed in microfluidic devices. Due to the small characteristic lengths of microreactors, phenomena such as mass transport via molecular diffusion occur within seconds. Typically, discrete slugs of an extract are created within microchannels for high specific interfacial area to achieve intensified mass transfer. A challenge...
This study investigates the relationship between total and ionic copper in samples taken from the Tualatin River and wastewater treatment facilities (WWTFs) that discharge into the Tualatin River. Copper speciation was analyzed by determining conditional stability constants and densities of copper binding ligands on the dissolved organic matter (DOM) in...
Decades of educational research has not reached and benefited most students due to the "implementation gap." The implementation gap is a term used to describe the divide between the number of research-based curricular materials created and the number that are broadly used in classrooms. A common approach to researching this...
Contamination of stormwater with Cu⁺², Pb⁺², and Zn⁺² has become an important issue with recognition of the neurotoxic effects of these metal ions on aquatic life. Low levels of aqueous Cu⁺² disrupt olfactory functioning in endangered Pacific Northwest salmon, decreasing their ability to avoid predation. One common solution is stormwater...
The cometabolic ability of Burkholderia vietnamiensis G4 grown on aromatic substrates was first assessed by resting suspended cells, and subsequently for cells encapsulated with and without slow release compounds (SRCs). In Chapter 3, benzyl alcohol was assessed as a food-grade growth substrate for promoting cometabolism of trichloroethene (TCE), via the...
Mixtures of 1,4-dioxane (1,4-D) and chlorinated aliphatic hydrocarbons (CAHs) are common and hazardous groundwater contaminants that can be challenging to address with traditional remediation strategies. Bioremediation through aerobic cometabolism has the potential to be an effective in-situ treatment strategy for these contaminants. Rhodococcus rhodochrous strain ATCC 21198 is capable of...
1,4-dioxane and chlorinated aliphatic hydrocarbons (CAHs) such as trichloroethylene (TCE) and 1,1-dichloroethene (1,1-DCE) are hazardous compounds commonly found in soil and groundwater. Bioremediation through aerobic cometabolism is a potential option for the remediation of these contaminated sites. The purpose of this study was to examine the use of different primary...
A year-long bench-scale treatability study was performed to assess the feasibility of using an activated sludge sequencing batch reactor (SBR) to treat a mixture of domestic wastewater and landfill leachate. A 50/50 (v/v) of domestic wastewater and landfill leachate was treated in a 1 L SBR operated on a 12...
Methods were developed for the co-encapsulation of slow release compounds (SRC) with viable microbial cells in alginate and gellan gum hydrogel beads, for the in-situ aerobic cometabolic treatment of groundwater contaminated with mixtures of 1,4-dioxane and chlorinated aliphatic hydrocarbons, which will be referred to as contaminants of concern (CoC). The...
This thesis characterizes the feedback between the instructor and student teams engaged in a Virtual Bioreactor (VBioR) Laboratory Project. The project allows senior-level chemical, biological, and environmental engineering students to apply their developing knowledge and skills in an industrially situated process optimization project. Feedback is an important tool for instructors...
Recent studies have discovered that salmon, specifically juvenile Coho Salmon, have their olfactory senses inhibited by the presence of low concentrations of copper concentrations at very low concentrations. Much of this copper is deposited on roadways by car brake pads during their use. The copper is carried with stormwater into...
Chlorinated solvents are common groundwater pollutants that often exist as mixtures resulting from the use of multiple solvents and their transformation into chlorinated daughter products. These sites are often co-contaminated with the solvent stabilizer 1,4-dioxane (1,4-D), which is not treated by traditional chlorinated solvent remediation techniques. Both 1,4-D and chlorinated...
Two methanotrophs, M. trichosporium OB3b and M. buryatense 5GB1, were encapsulated using two methods to investigate the potential of methane conversion for biofuel production. Ca-alginate and low melt agarose were used to immobilize the methanotrophs for batch and continuous flow column testing. Varying protein concentrations, residence times, and immobilization methods...
Reclaimed water is a key source in overall global water management and sustainability;
however, small concentrations of antibiotics in treated wastewater effluent threaten
induction of antibiotic resistance in naturally-occurring soil bacteria and pathogens in
irrigated soils. This type of chronic exposure has the potential to lead to more severe food...
Aromatic hydrocarbons represent a large class of environmental contaminants that have a broad range of structures, physicochemical properties, and toxicities. Arising from the burning of organic matter, particularly fossil fuels, they are both widespread and abundant in all environmental compartments. Both monoaromatic hydrocarbons (BTEX) and polycyclic aromatic hydrocarbons (PAHs) are...
Conventional wastewater treatment facilities using activated sludge, secondary clarifiers, and chlorine disinfection comprise a large portion of urban wastewater treatment practices in the United States. While highly adept at removing chemical, physical, and numerous biological contaminants, these treatment methods are ineffective at removing contaminants of emerging concern, such as antibiotics...
Approximately ninety percent of urban Vietnamese households are connected to septic tanks, from which up to three-quarters of the sludge is reported to be dumped into waterways in residential areas. Vietnam has a considerable prevalence of antibiotic misuse and resultant antibiotic-resistant bacteria (ARB) in the human microbiome. Due to the...
Multi-phase flow in porous media includes many instances of subsurface flow. Three-phase flow in particular is important in situations of enhanced oil recovery, CO2 sequestration, and groundwater remediation. Many studies have been performed on how two fluid phases (oil/water or air/water) behave in porous media, but very few studies exist...
Chlorinated aliphatic hydrocarbons (CAHs) like trichloroethene (TCE) were mostly used to replace drying cleaning fluids which contained hydrocarbons like benzene, and were highly flammable. Through improper disposal, storage, and spills, TCE and its downstream products, like cis-dichloroethene (cDCE) and vinyl chloride (VC), leached into groundwater and threaten human and environmental...
The natural production of methane via anaerobic digestion (AD) is facilitated by a complex community of microorganisms, primarily bacteria and archaea, referred to as the AD microbiome. AD is growing in prominence as a solution to the disposal of food waste, sewage sludge, and the organic fraction of municipal solid...
Acid whey is the largest byproduct of the dairy industry but to date has few useful applications and is frequently discarded as a result. However, acid whey has a high carbon content, making it a suitable co-substrate for anaerobic co-digestion with raw sewage sludge. The synergistic effect of co-digestion has...
Geologic CO₂ sequestration is a climate change mitigation strategy that prevents CO₂ emissions to the atmosphere by capturing CO₂ gasses from large point source emissions streams and then pressurizing and pumping the supercritical-state CO₂ into underground geologic storage reservoirs. Once underground, CO₂ is prevented from buoyant migration to the surface...
CisCis-Dichloroethylene (ciscis-DCE), 1,1,1-Trichloroethane (1,1,1-TCA), and 1,4-Dioxane (1,4-D) are chlorinated solvents used as solvents and degreasers in industrial cleaning agents that have become common groundwater contaminants. To develop an effective treatment method for these compounds, polyvinyl alcohol (PVA) and sodium alginate (SA) hydrogel beads were co-entrappcapsulated with Rhodococcus rhodochrous Strain ATCC...
1,4-Dioxane (dioxane) and cis-dichloroethylene (cDCE) are compounds commonly found in industrial cleaning and degreasing agents that are frequently present as groundwater contaminants. In an effort to develop a more effective treatment method for these compounds, hydrogel beads were fabricated with either gellan gum or a combination of polyvinyl alcohol (PVA)...
Nanoscale polymers (including nanoplastics) are widely present through commerce and make their way into the environment. As the improper disposal of plastic waste leads to continued accumulation and degradation of plastic pollution, the presence of plastic particles less than 1 micron (μm) in size (nanoplastics) will increase. Heightened concern over...
Nanoparticles (NPs), defined by their size (1-100 nm), are increasingly incorporated into commercial and industrial products due to their high surface area and unique properties. They can be designed for specific applications by manipulating composition, size, shape, and surface functionalization. As NP production and complexity increases, there is a need...
Calls for reform within engineering education frequently cite the need to better prepare the future workforce for the imminent challenges that they will face. The focus in preparing students for the workforce is often on the educational system and not on understanding the actual workplace. But if we are to...
Landfill leachate is a complex wastewater that contains high levels of ammonium (often over 250 ppm) and trace heavy metals (usually under 0.2 ppm). Microalgae have been shown to inexpensively and effectively treat wastewaters containing high loads of organics and nutrients, as well as adsorb metal ions. This thesis focuses...
This work is an attempt to develop a simple physical description for the initial
interactions between a bacterial cell and a substrate surface. This is done by
adopting a view that regards bacterial surface biomolecules not as secondary and
add-on contributors to the potential energy function that characterizes the
overall...