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...
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...
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...
A dissertation describing the results of a series of greenhouse experiments conducted to better understand phytoremediation in stormwater bioretention systems.
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...
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...
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...
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...
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)...
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...
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...
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...
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...
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,...
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...
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,...
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...
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...
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...
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...