Environmental Engineering Commons^™

Commercial Adsorbents For Co2 Removal For Biogas Upgradation: An Experimental Study, Aakriti Bagla

McKelvey School of Engineering Theses & Dissertations

No abstract provided.

Nanoscale Interfacial Control Of Ion Behaviors And Caco3 Formation In Environmental Systems, Yaguang Zhu

McKelvey School of Engineering Theses & Dissertations

Interfaces in environmental systems can change the distribution of pollutants and nutrients, determine the fate and transport of nanoparticles, and affect the efficiency of engineering projects. Complex interactions, including electrostatic interactions, Van der Waals interactions, chemical interactions, and ion-surface specific interactions, can all contribute to different ion, ion-pair, and nanoparticle formations near interfaces. Although environmental interfaces play critical roles, only a limited number of studies have considered the nanoscale picture of how they control ions and nanoparticles. Thus, this dissertation addresses three research questions: (1) How does sulfate chemically interact with calcium carbonate (CaCO3) during its heterogeneous formation on quartz …

Advancements In Pressurized Oxy-Combustion Process: Pollutant Control And Process Development, Piyush Kumar Verma

McKelvey School of Engineering Theses & Dissertations

The emission of carbon dioxide from the power industry is one of the major causes of climate change. However, it is well established that the development of human societies across the globe depends on reliable and dispatchable power, which are generally the source of these emissions. There has been a recent growth in the integration of intermittent sources such as wind and solar which are carbon free. But these intermittent sources have significant temporal changes in power production and thus lack reliability and dispatchablity. This is a complicated problem to solve. However, flexible power plants with carbon capture and storage, …

Droplet And Particle Dynamics In Aerosol Reactors And Environmental System, Sukrant Dhawan

McKelvey School of Engineering Theses & Dissertations

Aerosol science and engineering is an enabler for continual advances in nanomaterial synthesis. The spray-based techniques have been used extensively for the large-scale production of nanoparticles. Synthesis of particles with a desired the size and morphology is of key importance for exploiting their properties for their use in several emerging technologies. In contrast to useful nanomaterials, the aerosols from industrial flue gas, dust, indoor cooking, pathogens, and wildfire etc. are harmful to human health. It is important to understand how these harmful aerosols travel through the environment and potentially impact the health. It is also very critical to improve the …

Advanced Materials For Air Pollutants Removal In A Combustion System, Sungyoon Jung

McKelvey School of Engineering Theses & Dissertations

Air pollutants directly or indirectly impact human health and the environment. Large quantities of CO2, volatile organic compounds (VOCs), and particulate matter are emitted from combustion systems, and cause climate change, smog formation, and pose serious health risks. The increasing demand for the remediation of air pollutants at the source has drawn much attention to the use of advanced materials due to their high reactivities and special properties. In order to achieve the successful application of advanced materials for the remediation of problematic emissions, three aspects, (1) synthesis method, (2) characterization of materials’ structural properties, and (3) evaluation of materials’ …

Chemistry Of Nanoscale Solids And Organic Matter In Sustainable Water Management Systems, Xuanhao Wu

McKelvey School of Engineering Theses & Dissertations

To alleviate global water scarcity and improve public health, engineered water treatment and management systems have been developed for purifying contaminated water and desalinating brackish or ocean water. These engineered systems provide substantial amounts of potable water and lessen environmental concerns about the release of contaminated water. Wastewater treatment plants (WWTPs), water desalination plants (WDPs), and managed aquifer recharge systems (MARs) are three representative sustainable water management (SWM) systems. But the operation of all three poses two fundamental questions: (1) What is the fate of nanoscale solids (e.g., engineered nanomaterials, naturally occurring nanoparticles) in SWM systems and how will their …

Contemporary Problems In Aerosol Aggregation And Gelation, Pai Liu

McKelvey School of Engineering Theses & Dissertations

Aggregation of nanoparticles in aerosols is a fundamental phenomenon with important implications to diverse fields ranging from material synthesis to pollutant control. The past few decades have witnessed extensive research on investigating the structure and growth mechanism of aerosol aggregates with sizes spanning across several orders of magnitude. This dissertation focuses on some contemporary problems that remain unaddressed in this topical area. Aerosol aggregates in sub-micron regimes, which are formed via the irreversible collision and aggregation of solid nanoparticle monomers, are fractal-like in their morphology. A mathematical description of this seemingly random structure dates to the seminal works by Forest …

Modeling The Effects Of Distribution System Topology On Water Quality, Chun-Ying Chao

McKelvey School of Engineering Theses & Dissertations

Inadequate treatment of drinking water causes the formation of disinfection by-products and the regrowth of harmful microbial species. Various studies have addressed the problem of water quality monitoring, but very few have employed topological analysis, a valuable mathematical tool widely applied in biological, business, and social research. This thesis examines the relationship between the topological properties of water distribution systems and water-quality models. In particular, the research proposes a novel framework for mapping network topological attributes to water-quality models. This research adopts topological metrics to assess the accuracy of the predictions of chlorine concentrations in dead ends. It examines four …

Role Of Submicrometer Particles In Advanced Technologies Of Carbon Capture, Zhichao Li

McKelvey School of Engineering Theses & Dissertations

Oxy-combustion and post-combustion carbon capture technologies are two of the most promising strategies for carbon capture and storage (CCS), which is a commonly accepted approach to address the challenge of climate change. Pressurized oxy-combustion has been actively studied due to its great potential to enhance the power plant energy efficiency by recovering latent heat from water vapor condensation without incurring additional gas compression cost. On the other hand, amine-based CO2 scrubbers have been demonstrated to have high removal efficiency of CO2 with the possibility to recycle amine solutions, which makes the technology a promising candidate for post-combustion carbon capture. Nonetheless, …

Role Of Submicrometer Particles In Advanced Technologies Of Carbon Capture, Zhichao Li

McKelvey School of Engineering Theses & Dissertations

Oxy-combustion and post-combustion carbon capture technologies are two of the most promising strategies for carbon capture and storage (CCS), which is a commonly accepted approach to address the challenge of climate change. Pressurized oxy-combustion has been actively studied due to its great potential to enhance the power plant energy efficiency by recovering latent heat from water vapor condensation without incurring additional gas compression cost. On the other hand, amine-based CO2 scrubbers have been demonstrated to have high removal efficiency of CO2 with the possibility to recycle amine solutions, which makes the technology a promising candidate for post-combustion carbon capture. Nonetheless, …

Mechanisms Of Calcium Phosphate Mineralization On Biological Interfaces And Their Engineering Applications, Doyoon Kim

McKelvey School of Engineering Theses & Dissertations

All living organisms utilize phosphorus (P) as an essential component of their cell membranes, DNA and RNA, and adenosine triphosphate. Bones, in addition to bearing loads, play an important role in balancing P levels in our bodies. In bones, a network of collagen templates and calcium phosphate (CaP) nanocrystals builds hierarchical levels, from nano- to macroscale. Within this architecture, the thermodynamic properties of CaP minerals are influential. Despite the importance of nucleation, growth, and crystallization in collagen structures for tissue development, little kinetic study of these processes has been conducted due to the limited in situ techniques for monitoring these …

Developing Multi-Scale Models For Water Quality Management In Drinking Water Distribution Systems, Ahmed A. Abokifa

McKelvey School of Engineering Theses & Dissertations

Drinking water supply systems belong to the group of critical infrastructure systems that support the socioeconomic development of our modern societies. In addition, drinking water infrastructure plays a key role in the protection of public health by providing a common access to clean and safe water for all our municipal, industrial, and firefighting purposes. Yet, in the United States, much of our national water infrastructure is now approaching the end of its useful life while investments in its replacement and rehabilitation have been consistently inadequate. Furthermore, the aging water infrastructure has often been operated empirically, and the embracement of modern …

Synthesis Of Crumpled Graphene And Titanium Dioxide Based–Nanomaterials And The Application To Carbon Dioxide Photoreduction, Yao Nie

McKelvey School of Engineering Theses & Dissertations

With the rapid development of the economy, increasing combustion of fossils fuels has caused an increase in the atmospheric carbon dioxide (CO2) level, and has led to global climate change. As a mitigation approach, CO2 capture and conversion (CCC) can not only capture CO2, but also convert it to useable products, such as hydrocarbon fuels. Photocatalytic reduction is an attractive CCC option that directly harnesses inexpensive and abundant solar energy. Titanium dioxide (TiO2) is a widely used semiconductor for photocatalysis, and graphene nanosheets are a promising material for use in fabricating graphene-TiO2 hybridized photocatalysts. To realize the application of these …

Fundamental Studies Of Solid-Fuel Combustion Using A Two-Stage Flat-Flame Burner, Adewale Ayodeji Adeosun

McKelvey School of Engineering Theses & Dissertations

Innovative coal technologies are essential for addressing concerns about air pollution and global climate change. A key pathway to advancing these technologies is through developing a thorough understanding of the fundamental physical and chemical processes that occur during coal combustion. Ignition influences many aspects of coal combustion, including flame stability, submicron aerosol evolution, and char burnout. As important as ignition and these associated processes are, they are challenging to study because they depend on many factors, such as the combustion environment, particle size, and particle-particle interactions.

While there have been many studies of coal ignition, none have studied the process …

Multi-Scale Studies To Develop A Holistic Understanding Of Solid Fuel Combustion At Residential Scale, Sameer Patel

McKelvey School of Engineering Theses & Dissertations

Nearly 3 billion people rely on solid fuels for their cooking and heating needs, classifying them as “energy poor”. This poverty can be attributed to several factors, including a lack of resources (fuel), inefficient infrastructure (production and distribution), limited purchasing power (poverty), and ill-devised policies. Solid fuels, such as biomass, coal, and dung cakes, are burned in inefficient cookstoves. They generate products of incomplete combustion (PIC), such as CO, particulate matter (PM), and CH4, causing household air pollution (HAP) whose adverse impacts on both health and the environment have been well established.

HAP causes diseases such as chronic obstructive pulmonary …

Sub 2 Nm Particle Characterization In Systems With Aerosol Formation And Growth, Yang Wang

McKelvey School of Engineering Theses & Dissertations

Aerosol science and technology enable continual advances in material synthesis and atmospheric pollutant control. Among these advances, one important frontier is characterizing the initial stages of particle formation by real time measurement of particles below 2 nm in size. Sub 2 nm particles play important roles by acting as seeds for particle growth, ultimately determining the final properties of the generated particles. Tailoring nanoparticle properties requires a thorough understanding and precise control of the particle formation processes, which in turn requires characterizing nanoparticle formation from the initial stages. The knowledge on particle formation in early stages can also be applied …

Crumpled Graphene Oxide: Aerosol Synthesis And Environmental Applications, Yi Jiang

McKelvey School of Engineering Theses & Dissertations

Environmental technologies, such as for water treatment, have advanced significantly due to the rapid expansion and application of nanoscale material science and engineering. In particular, two-dimensional graphene oxide (GO), has demonstrated considerable potential for advancing and even revolutionizing some of these technologies, such as engineered photocatalysts and membranes. To realize such potential, an industrially scalable process is needed to produce monomeric and aggregation-resistant GO nanostructures/composites, in addition to new knowledge of material properties, behavior, and performance within an environmental context.

Research presented in this thesis addresses both scientific and engineering gaps through the development of a simple, yet robust aerosol-based …

Nanoparticle Formation In The Flame Synthesis Of Multicomponent Nanostructured Materials For Clean Energy Applications, Jiaxi Fang

McKelvey School of Engineering Theses & Dissertations

This dissertation studies the initial stages of particle formation during the combustion synthesis of multicomponent nanomaterials. Combustion is commonly used for the production of nanomaterials at industrial scales and has advantages of high production rates, low waste generation, and scalability. However, there are limitations in being able to apply this synthesis approach to more advanced multicomponent systems. Gas to particle conversion in flames occurs through precursor decomposition, collisional growth, coagulation, condensation, and sintering. There is a fundamental gap in knowledge on the initial stages of particle formation in flames below 2nm due to measurement difficulties and instrumentation limitations. Using a …

Nanostructured Thin Film Synthesis By Aerosol Chemical Vapor Deposition For Energy Storage Applications, Tandeep Singh Chadha

McKelvey School of Engineering Theses & Dissertations

Renewable energy sources offer a viable solution to the growing energy demand while mitigating concerns for greenhouse gas emissions and climate change. This has led to a tremendous momentum towards solar and wind-based energy harvesting technologies driving efficiencies higher and costs lower. However, the intermittent nature of these energy sources necessitates energy storage technologies, which remain the Achilles heel in meeting the renewable energy goals. This dissertation focusses on two approaches for addressing the needs of energy storage: first, targeting direct solar to fuel conversion via photoelectrochemical water-splitting and second, improving the performance of current rechargeable batteries by developing new …

Modeling, Simulation, And Analysis Of Lithium-Ion Batteries For Grid-Scale Applications, Matthew Thomas Lawder

McKelvey School of Engineering Theses & Dissertations

Lithium-ion batteries have become universally present in daily life, being used across a wide range of portable consumer electronics. These batteries are advantageous compared to other forms of energy storage due to their high energy density and long cycle life. These characteristics make lithium-ion batteries advantageous for many new and developing applications that require large scale energy storage such as electric vehicles and the utility grid. Typical uses for lithium-ion batteries require consistent cycling patterns that are predictable and easy to approximate across all uses, but new large scale applications will have much more dynamic demands. The cycling patterns for …