Environmental Engineering Commons^™

Developing Aero-Floating Treatment Wetland (Aeroftw) Scaffolds: A Non-Plastic Alternative To Conventional Plastic-Based Ftws, Ada C. Montoya Gomez

All Theses

This research was conducted to explore the possibility of constructing floating treatment wetlands (FTWs) without using plastic materials. FTWs are floating platforms that hold plants on the water’s surface, letting roots dangle within the water column, to help remove contaminants from contaminated water, especially in stormwater ponds. Many conventional FTWs are made with plastic components, such as mats and plastic cup containers, which can release microplastics into the environment over time. The goal of this project was to design and test a new type of FTW that does not depend on plastics to support FTW flotation. The study took place …

Investigation Of Low-Pressure Mercury Lamp System Configurations And Xenon Excimer Lamp System Development As Vacuum Ultraviolet Sources For Optimal Photolytic Degradation Of Poly-/Perfluoroalkyl Substances, Eman Zuhair Alhamdan

All Dissertations

PFAS are persistent synthetic chemicals, with unique properties that enable them to easily enter and accumulate in water sources. Their public health impacts have raised concern and highlighted the need for effective treatment. Numerous techniques for PFAS removal from water have been studied, few have proven the ability of breaking down PFAS rather than separating and concentrating it. Many of these methods are chain-length dependent, showing slower degradation rate of short-chain PFAS and requiring substantial amounts of energy, and chemical agents that may produce byproducts.

Among available PFAS destruction methods, direct photolysis by high-energy UV with wavelength below 200 nm …

What Is Passive And Active Release Retrofitting Rainwater Harvesting Systems?, Sarah E. Waickowski, Amy E. Scaroni, Beatriss H. Calhoun

Forestry and Natural Resources

Rainwater harvesting is the collection and temporary storage of rainwater for non-potable applications and stormwater management. Rainwater harvesting systems can be retrofitted with passive or active release to improve how well the systems manage stormwater runoff. This publication contains information that may be useful to municipalities, stormwater professionals, rainwater harvesting system owners and/or managers, homeowner associations, and stormwater educators, among others, on what is passive and active release, including their benefits and where to find more information.

Comparison Of The Recent Icrp Occupational Intakes Of Rradionuclides Series To Annual Limits On Intake (Ali) In The United States For Select Radionuclides, Aidan B. Barker

All Theses

Dose coefficients (DCs) and secondary limit values (such as the annual limit on intake [ALI] and derived air concentration [DAC]) are useful and convenient quantities in radiation protection (RP) for estimation of radiological dose and the practical application of dose limits. DCs link radioactivity intake to dose while secondary limit values express a dose limit in terms of the type and extent of exposure. The International Commission on Radiological Protection (ICRP), an international organization which provides guidance and recommendations for RP, calculates, tabulates, and updates DCs following new findings and updated knowledge relevant to dose determination (e.g. improved human biokinetics, …

Surface Reaction And Transportation Of Radium-226 In Marine Systems, Jiusi Wang

All Dissertations

Historical uses of radium (Ra)-containing self-luminous paint, such as on gauges and dials in naval ships, have led to the potential for such paint, and thus Ra, to be released into the marine environment. Radium-226 (²²⁶Ra) behavior in marine systems is not fully described in the literature, presenting a knowledge gap in the process of evaluating potential ecological impact of Ra in marine systems. This study explores various mechanisms contributing to Ra environmental transport in marine systems on a laboratory scale, including leaching, sorption, and diffusion. ²²⁶Ra leaching from watch hand dials containing radioactive luminous paint is …

Advancing Life Cycle Assessment Of Mass Timber: Environmental Performance, Circular Design And End-Of-Life Strategies, Muzan Williams Ijeoma

All Dissertations

Mass timber has emerged as a leading candidate for low-carbon construction, offering the dual benefits of reduced embodied emissions and biogenic carbon storage. Yet, fully realizing its sustainability potential requires a comprehensive and context-specific understanding of its environmental performance across the entire life cycle, from raw material production to building operation and beyond end-of-life (EoL). This dissertation advances life cycle assessment (LCA) practices for mass timber by addressing critical challenges across multiple phases of its life cycle. This dissertation is comprised of three published papers, and two submitted manuscripts. First, I conducted a critical review and meta-analysis of mass …

An Inference Approach For Assessing Place-Based Vulnerability To Heat Mortality, Junkang Xu, Chao Fan, Xing Xu, Haoying Han

Publications

A global increase in the frequency, severity, and scale of extreme heat raises concerns about human vulnerability to climate change and associated mortality. Heat vulnerability and mortality have largely been studied separately, lacking an understanding of their causation. Here, we create a non-parametric generalized inference approach that links socioeconomic, environmental, and infrastructure factors articulated in vulnerability theory and heat mortality between 2010 and 2020 for counties across the United States. We find that the lack of vegetation coverages drives mortality in the Southern U.S. and among Hispanic people. Limited air conditioning is a key factor in heat-related mortality among White …

Life Cycle Assessment Of The Cultivation Of Lettuce In A Hydroponic System Using The Nutrient Film Technique, Raquel Jordan

All Theses

Hydroponic systems are an emerging method of soilless crop cultivation typically done inside a greenhouse where nutrients are delivered dissolved in water rather than being supplied from the soil. Potential benefits of hydroponic systems include reduced irrigation requirements, higher crop yield per area, and the ability to grow crops year-round in nontraditional areas such as urban settings, cold climates, and sites with contaminated soil. However, hydroponic systems tend to have high energy requirements for lighting and climate control, which can yield significant environmental impacts. To explore the environmental impacts of cultivating lettuce in a nutrient film technique (NFT) hydroponic system, …

Evaluating The Impact Of Activated Carbon On The Biodegradation Of Btex Compounds, Megan Barkley

All Theses

BTEX compounds—benzene, toluene, ethylbenzene and xylenes—are toxic, volatile, aromatic hydrocarbons. They are primarily found in petroleum products and can easily enter the environment. Typical remediation techniques include sorption to activated carbon, pump and treat, and bioremediation. Research suggests that combining sorption to activated carbon and bioremediation may enhance BTEX removal. This study evaluates the impact of granular activated carbon (GAC) on the biodegradation of ethylbenzene and toluene, using an enrichment culture of aerobic bacteria.

The main objectives of this study are to grow and maintain a culture that degrades BTEX compounds, evaluate the effect of activated carbon on the biodegradation …

Life Cycle Assessment Of Sustainable Wastewater Systems - Algae-Based Wastewater Treatment, Harish Lakshmi Srinivasan

All Theses

This thesis studies the integration of an algae-based membrane bioreactor (MBR) and photobioreactor system into a domestic wastewater treatment facility, using the Clemson University WWTP as a reference plant. The proposed system replaces the conventional sequencing batch reactor and aerobic digester with a microalgae-bacteria symbiosis process, coupled with submerged ceramic membranes, an algal photobioreactor and anaerobic digestion for enhanced nutrient and energy recovery, which paves the way for water reuse and increased biological capacity in the future.

The study shows that overall energy consumption is reduced by approximately 18% compared to the existing conventional configuration. Further, methane production from anaerobic …

Evaluating (Bio)Degradation Of Carbon Tetrachloride In Fe(Iii)-Reducing Environments, Adam Rogers

All Theses

Understanding degradation of carbon tetrachloride in-situ is vital for many remediation projects across the world, yet conclusive evidence of its feasibility is lacking in previous studies.

The main objective of this research is to assess the potential for carbon tetrachloride attenuation by biological, abiotic, and combined processes in a Fe(III)-reducing aquifer. In doing so, it assesses the effect of pH and stoichiometric ratio on abiotic degradation of carbon tetrachloride using various reducing agents, evaluates iron-mediated versus direct biotic degradation of carbon tetrachloride using pure cultures under resting and growth conditions, and characterizes the effects of culture strain, electron acceptors and …

Effectiveness Of Electrosynthesized Hydrogen Peroxide In Urease Inactivation For Stabilization Of Source-Separated Urine To Recover Urea, Brooke E. Covert

All Theses

The practice of separating urine at a building scale, rather than mixing with domestic wastewater to be treated at water resource recovery facilities, allows for concentrated urine to be directly treated with the aim of resource recovery. However, source separation and treatment present challenges during separation, storage, and transport. This study evaluated the use of hydrogen peroxide-producing electrochemical cells, which represent a technology that uses electricity as an input, to stabilize urine through cathodically produced peroxide to enable downstream water and nutrient recovery. The electrochemical cells have been previously shown to stabilize urine with electrochemically produced peroxide as an effective …

Advancing Life Cycle Assessment For Environmental Sustainability Of Carbon Fiber-Reinforced Polymer Composites (Cfrps)), Hao Chen

All Dissertations

Carbon fiber-reinforced polymer composites (CFRPs) have emerged as promising materials, particularly for lightweight applications, with the potential to reduce environmental impacts across multiple sectors, including automotive, aerospace, and renewable energy. However, fully realizing their sustainability potential requires a more comprehensive and context-specific understanding of their environmental performance throughout the entire life cycle—from raw material production to end-of-life management.

This dissertation advances life cycle assessment (LCA) practices for CFRPs by addressing key challenges across multiple phases of the CFRP life cycle. First, I conducted a critical review and meta-analysis of carbon fiber manufacturing, revealing substantial variability in reported data on energy …

Modeling Disaster Resilience Through A Human-Centered Lens: Exposure, Vulnerability And Adaptation, Tong Liu

All Dissertations

The core of reframing and operationalizing disaster resilience with a human-centered lens is to incorporate concepts from socio-ecological resilience into engineering resilience to better understand the humans’ capability for disaster adaptation. Existing studies have drawn practical implications by identifying actionable thresholds for infrastructure systems under disasters, which can be easily applied by policymakers, emergency managers and municipal agencies. However, how individuals interact with, respond to, or adapt under these infrastructure thresholds remain understudied. This hinders the operationalization of disaster resilience at the human scale.

First, I examined exposure by analyzing how configuration and distribution of urban infrastructure systems, such as …

Nature-Based Solutions For Urban Stormwater Management, Nima Zafarmomen, Vidya Samadi, Susan Lunt

Forestry and Natural Resources

This paper explores Nature-based Solutions (NbS) for urban stormwater management, emphasizing their role in mitigating runoff, reducing flood risks, and improving water quality. Bioretention systems (BRS), green roofs, permeable pavements, and vegetated swales utilize natural processes such as infiltration, evapotranspiration, and filtration to manage stormwater while promoting urban resilience and supporting biodiversity effectively. The performance of these solutions depends on vegetation, soil, and climatic parameters, highlighting the need for context-specific design and implementation. While NbS present sustainable alternatives to conventional infrastructure, technical, economic, social, and institutional challenges require interdisciplinary collaboration and supportive policies to unlock their full potential.

Community Wastewater Treatment Resilience Assessment, Tristan Veal

All Theses

With the rising threat of climate change and cascading impacts from infrastructure failure there is a growing need to strengthen community resilience. Theoretical and practical resilience frameworks are available, but they vary in aim and scope; there is no standard tool to assess resilience. This research expands on the resilience matrix (RM) application methods of previous research completed by the United States Army Corps of Engineers (USACE) and Clemson University. That work focused on drinking water treatment systems and developed a few dozen specific indicators, or metrics, to quantify resilience. This research adds wastewater infrastructure with the aim of identifying …

Evaluating The Role Of Electrostatic Forces In The Adsorption Of Perfluoroalkyl Substances To Granular Activated Carbon, Thomas A. Mccall

All Theses

In response to new drinking water regulations announced by the EPA in 2024, many municipalities will need to monitor concentrations and implement new treatments to address PFAS, a class of anthropogenic organic contaminants. A leading technology for this application is GAC adsorption due to its familiarity and availability. The adsorption of four PFAS species (PFBA, PFBS, PFOA and PFOS) to Calgon Filtrasorb400 (F400) was evaluated for a range of pH and ionic strength conditions to investigate the role of electrostatic interactions in adsorption capacity. These PFAS are all strong acids, so pH was used as a control for GAC surface …

A Parametric Study Of Compact Wind Borne Debris In Tornadoes, Akash Yadav

All Theses

Debris lofted and transported by tornadoes is a significant source of damage during these storms. Several approaches have been taken to model such debris flight, ranging in complexity from fine-scale CFD simulations to coupling the compact debris flight equations with simplified analytic models for the tornado vortex. Both approaches have their merits, though the latter comes with significantly lower computational costs. Despite the simplifications, this second approach has successfully captured details of debris flight events established in post-tornado forensic surveys. Herein, we take advantage of the low computational cost of the latter approach to undertake a detailed parametric study of …

Ceramic Membrane Evaluation Via Automated Filtration Systems For Water Treatment And Resource Recovery, Weiming Qi

All Dissertations

Membranes are an advanced and mature water and wastewater treatment technology. Membrane fouling is a key difficulty for all membrane filtration processes, leading to significant attention in the literature over the years. A common problem in laboratory-scale membrane research is that the testing methods in the laboratory are often quite different than industrial applications due to the limitations of manual experimental setups. An automated membrane filtration apparatus was built in the lab to solve this problem by allowing long-term filtration, frequent backwash and CIP, and high-accuracy operation. The filtration system achieves different cleaning strategies for both theoretical research and practical …

Understanding Conversion Of Long Chain Fatty Acids In Anaerobic Digestion Systems, Julia Ann Funk

All Dissertations

Anaerobic co-digestion with fats, oils, and grease (FOG) waste can increase energy production due to the high methane potential of lipids. However, adding FOG can lead to operational issues caused by accumulating saturated long-chain fatty acids (LCFA). My research explored why saturated LCFAs are often the primary intermediate that accumulates and the microbial sensitives of the populations responsible for their degradation. In each batch or semi-continuous experiment, all intermediates of FOG degradation, including LCFAs, volatile fatty acids (VFAs), Hydrogen gas (H₂), and endpoint methane production, were paired with temporal quantitative polymerase chain reaction (qPCR) of the Syntrophomonas genus …

Changes In The Western Flank Of The North Atlantic Subtropical High Since 1140 Ce: Extremes, Drivers, And Hydroclimatic Patterns, Joshua C. Bregy, Justin T. Maxwell, Scott M. Robeson, Grant L. Harley, Valerie Trouet

Publications

Summer circulation and moisture patterns in the Southeast United States are controlled by the position of the North Atlantic subtropical high. In a warming climate, the subtropical high is projected to strengthen and expand west, but there remains uncertainty regarding its variability and linkages to natural drivers. Here, we use a tree-ring network across the Southeast United States to reconstruct the relative intensity of the pressure gradient across the subtropical high’s western flank over the past 870 years. Variations in the flank’s position and the pressure gradient have been a major driver of the hydroclimate—including creating a Southeast-Caribbean moisture dipole—since …

Electrochemical Techniques For The Treatment Of Source-Separated Urine, Philip Arve

All Dissertations

Urine makes up approximately 1% of the total volume of municipal wastewater, but it contributes up to 75% of the nitrogen and 50% of the phosphorus received by publicly owned treatment works (POTWs). These elements are essential nutrients for plant growth and trigger algal blooms when released into natural bodies of water, resulting in rapid ecological degradation. Removing these nutrients from municipal wastewater is energy intensive and often operationally sensitive. The past few decades have seen an increase in focus on the source-separation and side-stream treatment of urine.

Urine characteristics differ greatly from those of municipal wastewater, presenting an opportunity …

Interpreting Strain Caused By Transient Well Testing, Soheil Roudini

All Dissertations

Understanding reservoir properties and structure is essential to managing subsurface operations, such as geologic storage of CO₂ or production of water, hydrocarbons or heat. Previous work demonstrated the potential of analyzing strain data during transient well tests by estimating hydraulic diffusivity using a type-curve-like approach. The following dissertation aims to pursue this potential by developing and evaluating methods for interpreting strain tensor data to improve subsurface characterization. The research advances the classic, intuitive method of using type-curves to interpret well tests, but it also brings together modern computational methods from machine learning, proxy modeling and Bayesian inversion, and it …

Assessing The Potential For Photosynthetic Degradation Of Per- And Polyfluoroalkyl Substances, Marlow Thomas

All Theses

PFAS is a prevalent groundwater contaminant. It has been known to cause many health issues for humans and animals including cancer and several diseases. A main problem faced with PFAS is contamination in groundwater. Remediation strategies have been and continue to be researched to try to mitigate this issue. Current treatment strategies to mitigate PFAS include the use of granular activated carbon, ion exchange, chemical oxidation, and many hybrid treatments. There has not been one treatment technology to date that has prevailed as the best due to monetary and time constraints.

The main intention behind this research is to examine …

Life Cycle Assessment Approach For Energy Usage In Animal Rendering Plants, Abel Binoy Mathew

All Theses

The animal rendering industry plays a crucial role in transforming waste products from livestock production and meat processing facilities into valuable and economically beneficial products, promoting both resource efficiency and sustainability. This study uses a life cycle assessment (LCA) approach to evaluate energy usage and greenhouse gas emissions in animal rendering plants, focusing on electricity and natural gas as the main energy inputs for plant operation. This research examines three distinct rendering facilities, each processing different raw materials, to quantify the environmental impacts of rendering operations. Site visits, data collection, and real-time monitoring were used to capture energy use across …

Microbial-Chemical Degradation Of Styrene In Co-Mingled Plumes With Ethylbenzene, Benzene, And Carbon Tetrachloride, Marcela C. Flórez-García

All Theses

Industrial sites contaminated with a complex matrix of chemicals represent a problem for the ecosystem and a high risk for the health of all individuals. That is why remediation strategies are needed to mitigate this environmental impact. The latex zone, located at the Corteva industrial site in San Lorenzo, Argentina, is the subject of this research. The environmental impacts in this area are a consequence of petrochemical operations carried out for many years.

Monoaromatic hydrocarbons such as styrene, ethylbenzene, and benzene, and chlorinated methanes like carbon tetrachloride, chloroform, dichloromethane, and chloromethane are among the contaminants identified at the site that …

Supporting Holistic, Informed, Decision-Making Through The Complementarity Of Life Cycle Assessment And Radiological Protection, Bryanna Wattier-Weisensee

All Dissertations

Decision making is challenging and it is necessary to consider all relevant data to make an informed decision. The work herein provides a pathway wherein the fields of radiological protection and life cycle assessment (LCA) can be utilized synergistically to benefit the decision-making using the other (and vice versa). Specifically, LCA parallels decision-aiding techniques used in the optimization of radiological protection and LCA includes an ionizing radiation potential (IRP) impact category wherein the impacts associated with an emission of radioactive material is quantified to determine the human health impact. Thus this body of work focuses on (1) expanding the platform …

Degradation Products And Microbial Communities Associated With The Conversion Of Five Long-Chain Fatty Acids Relevant For Anaerobic Co-Digestion Of Fog With Sludge, Claire Funk

All Theses

Anaerobic digestion is a technology that allows wastewater treatment plants to convert sludge to energy by recovering the biogas produced during the breakdown of proteins, carbohydrates, and lipids. Furthermore, adding fats, oils, and greases (FOG) through co-digestion with wastewater sludge can increase energy production as lipids have a higher methane yield than proteins and carbohydrates. However, adding FOG can also lead to operational problems in the digester due to the potential accumulation of certain long-chain fatty acids (LCFAs). Current research is limiting in the degradation pathways of prominent LCFAs in FOG and the microbial communities responsible for their degradation

The …

Extraction Of Neutron-Gamma Irradiated Diffusion Pump Oils, Cooper L. Tillman

All Theses

This work successfully demonstrates solvent extraction methods for separation of oil from the by-products when two commercially available vacuum pump oils were exposed to an intense neutron and gamma-ray radiation environment. Nuclear fusion power at a commercial scale has accelerated the need for radiation resistant vacuum technology, such as oil-based diffusion pumps. Polyphenyl ether and aromatic silicone oils were irradiated at the Rhode Island Nuclear Science Center (RINSC) up to MGy absorbed doses with neutron and gamma-ray radiation. Solvent extractions were performed using hexane and isopropanol to characterize the oil extraction as a function of total absorbed dose. The by-products …

Hydrogen Isotope Exchange On Diffusion Pump Oils, Carson G. Allen

All Theses

The extent of isotopic exchange of deuterium and tritium with protium atoms in hydrocarbon pump oil was investigated as a means to quantify the chemical stability of a mineral oil, a silicone oil, and a polyphenyl ether oil as candidates for implementation in a diffusion pump. In its target application at a fusion power plant, a chemically stable and radiation hard oil offers substantial reductions in tritium inventory, electrical consumption, and operational pump expenses over alternate solutions for vacuum induction. Select oils were introduced to deuterium and tritium isotopes in a high temperature environment, analogous to an operating vacuum pump. …