Engineering Commons^™

Predicting Water Quality Vulnerability Under Climate Change With Machine Learning, Khanh Thi Nhu Nguyen

Doctoral Dissertations

Water quality deterioration is a global and pervasive issue due to pollution caused by industrialization, urbanization, agriculturalization, and human population growth in the modern era. This issue is even more challenging in the context of climate change due to warming temperatures and the intensification of precipitation. Therefore, assessing the potential impacts of climate change on water quality is a concern. Assessment is necessary so that planners can prepare for and reduce the negative impacts on water quality. At present, climate change impact assessment frameworks are relatively adolescent. Most studies rely on climate projections from General Circulation Models for simulations of …

Enhancing Management Of Built And Natural Water And Sanitation Systems With Data Science, Nelson Da Luz

Doctoral Dissertations

In the age of the data revolution, the civil engineer can enhance the management of infrastructure systems using new techniques focused on data. This dissertation present three studies in which data science approaches are used to enhance management of water and sanitation systems in both the built and natural environments. Chapters 1 and 2 focus on improving methods for data collection relating to water quality monitoring. In Chapter 1, the efficacy of different water quality sampling program designs is evaluated as the programs relate to meeting monitoring goals. Considerations include how timing, location, and distribution system operations can affect monitoring …

The Role Of Extracellular Polymeric Substances In The Accumulation And Transport Of Polystyrene Nanoparticles In Biofilms, Joann Marie Rodríguez Suarez

Doctoral Dissertations

With the increasing number of nanotechnology applications, it is reasonable to expect nanoparticles to be ubiquitous in biofilms found in natural and engineered aquatic systems. We studied the impact of the degree of cross-linking on the deposition and diffusion of polystyrene nanoparticles (NPs) in alginate model biofilm matrices in the presence and absence of calcium cross-linkers using image correlation methods and single particle tracking. We found that cross-linking increases the viscoelasticity and hydration of the polymeric matrix and leads to structural changes that can restrict and alter the diffusive behavior of NPs, but the magnitude of the effects on diffusion …

Analysis And Fate Of 2,6-Dichloro-1,4-Benzoquinone In Real And Model Drinking Waters, Aarthi Mohan

Doctoral Dissertations

For many years chlorination has served as a barrier to protect human health from waterborne disease outbreaks. Chlorine is viewed as a near-universal oxidant and disinfectant, that provides a stable residual preventing microbial re-growth all the way through the consumer’s tap. Upon reaction with natural organic matter (NOM) however, it forms disinfection by-products (DBPs) many of which are potent human carcinogens and therefore have been of research interest since the 1970’s (Froese et al., 1999; Krasner et al., 2006, 1989; Richardson, 2003; Rook, 1976, 1974; Singer, 1994). The trihalomethanes (THMs) and haloacetic acids (HAAs) are the most prevalent (Krasner et …

Size Progression Of Oxygenic Photogranules (Opgs) And Its Effect On Opg Wastewater Treatment, Ahmed S.A. Abouhend

Doctoral Dissertations

In recent years, the oxygenic photogranule (OPG) process has gained increasing interest because of its potential to treat wastewater without supplemental aeration. Oxygenic photogranules (OPGs) are dense spherical aggregates comprised of phototrophic and nonphototrophic microorganisms. In OPG wastewater treatment reactors, photogranules grow in number as well as in size. The primary goal of this dissertation was to investigate how OPGs grow in size and how the growth affects their structure and functions. We found that OPGs undergo structural changes as they grow bigger in size. As OPGs grow larger, filamentous cyanobacteria become enriched while other phototrophic microbes diminish significantly. OPGs …

Modeling Power Generation Losses Due To Environmental And Fish Passage Attraction Flows At A Run-Of-River Hydroelectric Operation In The Northeast, Elizabeth A. Lotter

Environmental & Water Resources Engineering Masters Projects

Environmental mitigation represents an important, recurring cost to the hydropower industry, the largest renewable power source in the United States. Environmental flows are one such expense whereby hydro operations maintain a minimum flow in the river to mitigate impacts on aquatic and riparian ecosystems. Any hydroelectric facility may have a habitat maintenance flow requirement, but facilities with assisted aquatic organism passage structures, or fishways, may be subject to additional flow requirements associated with specific species migrations. This study assesses the economic impact of meeting environmental flow requirements in terms of losses to power generation at a representative hydroelectric facility and …

Natural Organic Matter (Nom) Precursors Characterization In Source Water By Surrogate Measurements And Disinfection Byproducts (Dbps) Analysis, Mohammad (Kiron) Shakhawat

Environmental & Water Resources Engineering Masters Projects

Natural organic matter (NOM) is the main source of organic precursors for organic disinfection byproducts (DBPs) in treated drinking water.Aquatic NOM is a heterogeneous mixture consisting of both hydrophobic and hydrophilic compounds. The hydrophobic fraction includes humic substances, primarily humic acids and fulvic acids. In most waters, fulvic acid is considered to be the major portion of the hydrophobic fraction. Humic substances are formed by decaying vegetative matter, such as lignin. Lignin is found in plants and is quite resistant to biodegradation, yet it is reactive with oxidants, such as chlorine. Thus, water continuing higher amounts of aromatic hydrophobic humic …

Weatherization And Energy Security: A Review Of Recent Events In Ercot, Golbon Zakeri, Maria Hmaria Hernandez, Matthew Lackner, James Manwell

Publications

Purpose of Review

This review addresses the question of energy security. With the transition of energy generation fleet to cleaner, more sustainable electricity production, energy security is a topic of increasing importance.

Recent Findings

Recent events in Texas brought the concept of energy security to the fore. In this review, we examine the makeup of electricity generation and the causes of the February 2021 blackout of Texas. We will investigate the cost/benefit of winterization in Texas and ask why this was not undertaken subsequent to a similar event in 2011.

Summary

We investigate the case of Texas blackout of February …

Influence Of Foundation Damping On Offshore Wind Turbine Monopile Design Loads, Wystan Carswell, Sanjay R. Arwade, Jörgen Johansson, Don J. Degroot

Publications

The dynamic behavior of offshore wind turbines (OWTs) must be designed considering stochastic load amplitudes and frequencies from waves and mechanical loads associated with the spinning rotor during power production. The proximity of the OWT natural frequency to excitation frequencies combined with low damping necessitates a thorough analysis of sources of damping; of these sources of damping, least is known about the contributions of damping from soil-structure interaction (foundation damping). This paper studies the influence of foundation damping on cyclic load demand for monopile-supported OWTs considering the design situations of power production, emergency shutdown, and parked conditions. The NREL 5 …

A Moment In The Sun: Solar Nowcasting From Multispectral Satellite Data Using Self-Supervised Learning, Akansha Singh Bansal, Trapit Bansal, David Irwin

Publications

ABSTRACT

Solar energy is now the cheapest form of electricity in history. Unfortunately,

signi.cantly increasing the electric grid’s fraction of

solar energy remains challenging due to its variability, which makes

balancing electricity’s supply and demand more di.cult. While

thermal generators’ ramp rate—the maximum rate at which they

can change their energy generation—is .nite, solar energy’s ramp

rate is essentially in.nite. Thus, accurate near-term solar forecasting,

or nowcasting, is important to provide advance warnings to

adjust thermal generator output in response to variations in solar

generation to ensure a balanced supply and demand. To address the

problem, this paper develops a …

The Sustainability Of Decarbonizing The Grid: A Multi-Model Decision Analysis Applied To Mexico, Rodrigo Mercado Fernandez, Erin Baker

Publications

Mexico recognizes its vulnerability to the effects of climate change, including sea level rise, increasing average temperatures, more frequent extreme weather events and changes to the hydrological cycle. Because of these concerns Mexico has a vested interest in developing sustainable strategies for mitigating climate change as it develops its electricity grid. In this study, we use a set of sustainability criteria to evaluate a number of model-derived pathways for the electricity grid aimed at meeting Mexico's climate goals. We use a multi-step approach, combining pathways from multiple large scale global models with a detailed electricity model to leverage geographic information …