Evaluation Of The Mechanisms And Effectiveness Of Nano-Hydroxides, Wood And Dairy Manure-Derived Biochars To Remove Fluoride And Heavy Metals From Water, Anna Rose Wallace, Wenjie Sun Dr, Chunming Su Dr

Civil and Environmental Engineering Theses and Dissertations

The development of effective treatment processes for the removal contaminants, such as fluoride and heavy metals, from polluted water have been urgently needed due to serious environmental health and safety concerns. In this dissertation, a variety of materials including various (hydro)oxide nanomaterials, biochars and surface modified biochar were studied to evaluate their effectiveness and mechanism on removing fluoride or mixed heavy metals from water.

In the Chapter 2, this study investigated the adsorptive removal of fluoride from water using various (hydro)oxide nanomaterials, focusing on ferrihydrite, hydroxyapatite (HAP) and brucite, which have the potential to be used as sorbents for surface …

Concentrations, Sources, And Health Risks Of Particulate Matter In Southeast Us.: Current Status And Future Changes, Fenglin Han

LSU Doctoral Dissertations

Evaluation of long-term air quality trends and prediction of future air quality may help to design and demonstrate effectiveness of control strategies and guide future air quality management. As one of the six criteria air pollutants (CAPs) regulated by the US Environmental Protection Agency (EPA), particulate matter with aerodynamic diameter of 2.5 µm or less (PM_2.5) is of great interests since it has adverse effects on human health, visibility and climate. This study aims to understand the current status and future changes in concentrations, sources, and health risks of PM_2.5 in Southeast US. Firstly, observations were analyzed …

Role Of Groundwater-Lake Interactions On The Behavior Of Chemicals In A Nearshore Aquifer, Sabina Rakhimbekova

Electronic Thesis and Dissertation Repository

It is well recognized that groundwater-surface water interactions play an important role in controlling the flux of groundwater-derived inorganic chemicals to surface waters. While these interactions have been well-studied in marine, and river and stream settings, the influence of these interactions on chemical fluxes to large lakes is poorly understood. Nearshore aquifers adjacent to inland coastal waters, such as the Great Lakes, are characterized by dynamic flow patterns and the mixing of groundwater and lake water, which have distinct chemical compositions. This sets up an important reaction zone in the nearshore aquifer that may modify the fate of groundwater-derived chemicals …

Partial Nitritation Anammox Process For Sidestream Wastewater Treatment In Mabr Technology, Panagiota Stamatopoulou

Electronic Thesis and Dissertation Repository

There has been an increased interest in alternative wastewater treatment systems to improve nutrients removal and energy consumptions while achieving acceptable discharge limits. Wastewater treatment plants (WWTP) have shifted their interest in treating the sidestream wastewater; a reject liquid post anaerobic digestion, rich in ammonium-nitrogen. A dedicated sidestream wastewater treatment unit has become an attractive option with the finding of a relatively new species of bacteria, anaerobic ammonium oxidizers (anammox), able to convert ammonium and nitrite into nitrogen gas. However, anammox bacteria are sensitive in environmental changes, and in combination with their low growth rate, it is challenging to establish …

Anaerobic Digestion Modeling Of A High Rate Acidification Pre-Treatment Technology, Connor Pritty

Electronic Thesis and Dissertation Repository

Through the application of a computerized model (BioWin), anaerobic co-digestion (AcoD) of source separated organics (SSO) and a high rate acidification technology (pretreatment) for a conventional wastewater treatment plant was reviewed. Through this combined approach of high rate acidification, and co-digestion techniques it was found that the experimental modeling scenarios offered increases when compared to the existing base scenario production levels. With the addition of the high rate acidification technology and application of source separated organics the maximum increases in biogas production came when an OLR of 5.24 kg-COD/m³/day and 97g COD/L/d was experimentally modeled. It is therefore, recommended that …

Flood Dynamics In The Portland Metropolitan Area, Past, Present, And Future, Lumas Terence Helaire

Dissertations and Theses

The Portland area has an extensive flood history since it was founded in 1845. In the late 19th century, the Portland area was prone to flooding from snowmelt freshets (3-6 months duration) and brief winter rain or rain-on-snow events. Since that time the magnitude of spring freshets has been curtailed by 45% due to climate change, flow diversions, and reservoir management. Along with changes in hydrology, the bathymetry of the Lower Columbia River has been altered by the dredging of the navigation channel, diking, and land reclamation. To understand how these changes in hydrology and bathymetry have affected tidal and …

Treatment Of Perchlorate And Multiple Oxyanions: Chemical And Biological Investigations, Mark Elkouz

UNLV Theses, Dissertations, Professional Papers, and Capstones

Groundwater contamination with oxyanions is an issue that must be addressed for environmental, ecological and societal reasons. Chemical and biological treatment methods of reduction are already known and practiced, but the simultaneous presence of multiple oxyanions can add complicating effects to treatment sequence and efficacy. This research was concerned with the investigation of the chemical reductive treatment of Cr(VI) using both calcium polysulfide (CaSx) and ferrous sulfate (FeSO4), and the biological reductive treatment of chlorate, Cr(VI), nitrate and perchlorate using multiple organic substrates. The chemical treatment phase consisted of initial jar tests, using CaSx and FeSO4, followed by a laboratory …

Design Of Efficient Carbon-Based Adsorbents For The Removal Of Organic And Inorganic Water Contaminants, Sayedeh Soroosh Mortazavian Dehkordi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Granular activated carbon (AC) and biochar (BC) are two carbon-based adsorbents commonly used for water and wastewater treatment. However, these adsorbents have drawbacks that suppress their aqueous contaminants removal efficiency. Their major disadvantages are that AC has low selectivity and reusability potential, and BC has a hydrophobic nature.

The scope of this dissertation is to enhance the performance of commonly-used carbon-based adsorbents for the removal of organic and inorganic water contaminants and to understand the interactive mechanism of contaminants’ ions/molecules with adsorbents. Hexavalent chromium (Cr(VI)) and trichloroethylene (TCE) are two types of inorganic and organic water contaminants, respectively, which are …

Carbon Management And Volatile Fatty Acid Production In Primary Clarifiers At A Wastewater Treatment Plant, Brittany Nicole Radke

UNLV Theses, Dissertations, Professional Papers, and Capstones

An increasing number of treatment plants are required to remove nutrients from domestic wastewater to lessen the impact of nutrient loading to water bodies. Enhanced Biological Phosphorus Removal (EBPR) is one of the processes commonly used to remove phosphorus from domestic wastewater. The presence of an adequate quantity of volatile fatty acids (VFA) in the wastewater influent to EBPR is important for process efficiency and stability. The objective of this research was to investigate the production of VFAs through fermentation of sludge in primary clarifiers as it related to improving nutrient removal, primarily targeting phosphorus.

The research tested, in full-scale, …

Application Of Data-Driven And Process-Based Modeling Approaches For Water Quality Simulation In Lakes And Freshwater Reservoirs, Ali Saber Sichani

UNLV Theses, Dissertations, Professional Papers, and Capstones

Lakes and freshwater reservoirs often serve as the primary drinking and irrigation water sources for surrounding communities. They provide recreational and tourism opportunities, thereby promoting the prosperity of neighboring communities. Reliable estimates of water quality in lakes and reservoirs can improve management practices to protect water resources.

Seasonal water temperature and solar shortwave radiation variations, and their subsequent interactions with water column aquatic life, combined with seasonal variations of mixing intensity throughout the water column, result in variations of water quality constituents with depth during the annual cycle. The complexity of these variations entails the use of advanced water quality …

Evaluation Of Titanosilicate Materials For The Sorption Of Cesium And Strontium From High Level Wastes, Matheus Tolentino Lauar

UNLV Theses, Dissertations, Professional Papers, and Capstones

Treatment of high-level waste (HLW) stored in the U.S. Department of Energy (U.S. DOE) sites of Hanford and Savannah River involves the separation of radioactive cesium (137Cs) and strontium (90Sr). Challenges in treating the liquid HLW includes high alkalinity or acidity, and high salt content, many orders of magnitude above Cs and Sr concentrations. Ion exchange is the preferred process for removing these compounds, due to the availability of selective media and large volume-processing capacity by column operations. The crystalline silicotitanate (Na2Ti2O3SiO4·2H2O), i.e. CST, which structure is analog to the mineral sitinakite, is considered the reference material for this application. …

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 …

Utility Of Bench Scale Sand Tank Experiments At Assessing Permeable Reactive Barrier Design, Brandon Meier

UNLV Theses, Dissertations, Professional Papers, and Capstones

The objective of this work was to evaluate the utility of bench scale sand tank experiments at assessing permeable reactive barrier (PRB) design. Our criteria for meeting this goal was that differences between PRB designs could be identified solely by measuring concentration in outflow from the sand tank models. For our PRB designs (funnel-and-gate, staggered wells, and parallel bars), numerical simulations clearly showed that PRB design had a quantifiable effect on outflow concentration, provided that the solute reacted with the PRB materials. Conversely, use of a conservative (non-reactive) solute did not allow us to discern between PRB design alternatives. Employing …

Spatial And Temporal Characteristics Of Temperature-Precipitation Covariability Across Canada In A Changing Climate, Harsimrenjit Singh

Electronic Thesis and Dissertation Repository

Changes in the regional characteristics of temperature and precipitation can intensify the occurrence and severity of extreme events such as rain-on-snow induced flooding, droughts and wildfires. Analyzing these climate variables in isolation without considering their interdependencies might result in severe underestimation of their combined effects. In this study, copula functions are used to describe the joint behaviour of temperature and precipitation across Canada over a historical period of 1910-present using observations and further till the end of the 21st century using three large ensembles of regional climate models. Moreover, given the lack of observation data over Canada, gridded datasets are …

College Of Engineering Senior Design Competition Fall 2019, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge. The senior design competition helps focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects on …

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 …

Energy & Carbon Neutral Nyc, Evan Banks, Elena Zimareva, Elena Malysheva

Publications and Research

In 2016, the world's leading countries signed the Paris Agreement which focused on reducing anthropogenic climate change on the planet. On May 2019, New York State and New York City declared its own ambitious goals aimed at decarbonizing the city and restricting the state’s energy use to relying completely on renewables.

Some of these goals specifically target infrastructure in the city since estimates cite buildings as accounting for nearly 70% of New York’s energy use. The main law of New York’s Climate Policy, Local Law 97, requires all buildings over 25,000 sq ft to reduce their CO2 footprint by 40% …

Thermodynamic Model Of Co2 Deposition In Cold Climates, Sandra K. S. Boetcher, Ted Von Hippel, Matthew J. Traum

Publications

A thermodynamic model, borrowing ideas from psychrometric principles, of a cryogenic direct-air CO2-capture system utilizing a precooler is used to estimate the optimal CO2 removal fraction to minimize energy input per tonne of CO2. Energy costs to operate the system scale almost linearly with the temperature drop between the ingested air and the cryogenic desublimation temperature of CO2, driving siting to the coldest accessible locations. System performance in three Arctic/Antarctic regions where the proposed system can potentially be located is analyzed. Colder ambient temperatures provide colder system input air temperature yielding lower CO2 removal energy requirements. A case is also …

Model Block Press Design, Ben Todd Van Hamersveld, Chester Wong, Alexander Wing-Jon Giannousis

Mechanical Engineering

This project’s goal is to redesign the Center for Vocational Building Technology (CVBT) BP9 earth block press, which makes 1/3 scale compressed earth blocks to build demonstration model homes in Thailand. The full-scale block press, the BP6, provides a sustainable and affordable technique for constructing habitable homes in Thailand. The BP9 serves as a tool to inform the public of the advantages of human-powered earth block presses through demonstration. The BP9 press design has multiple problems: it is too expensive to manufacture, there is too much friction when used, it has several weak points due to users unintentionally applying excessive …

Cytotoxicity And Mutagenicity Of Disinfection Byproduct Mixtures Formulated Using Free Chlorine And Monochloramine, Yonas Ghebremedhin

Graduate Theses and Dissertations

Bioassays have been used extensively to assess various toxicity endpoints of drinking water disinfection byproducts (DBPs), but an emphasis on single compounds prevails. In this research, DBP mixtures were assessed using a cytotoxicity test with Chinese Hamster Ovary (CHO) cells and an Ames fluctuation test with Salmonella typhimurium TA-98 and TA-100 with and without S9 rat liver homogenate. Seven whole mixture DBP concentrates were formulated using reconstituted natural organic matter (NOM) extracts from the Upper Mississippi River using scaled disinfectant dosing protocols with free chlorine and monochloramine in the presence and absence of added bromide. DBPs were identified by gas …

Underwater Particle Image Velocimetry (Piv) Measurement Of Turbulence Over Mussel Bed In A Deepsite Of Lake Michigan, Tong Jin

Theses and Dissertations

The influence of the benthic filter feeders, such as bivalves, on ecosystem plankton, and nutrient dynamics is considered significant in shallow marine and freshwater systems. Recent indirect evidence showed that the profundal quagga mussels (Dreissena rostriformis bugensis) have fundamentally altered energy flow and dynamics of nutrients and phytoplankton in Lake Michigan and other Great Lakes. To investigate the phytoplankton grazing rate of the quagga mussel and the mussel siphon currents induced bio-mixing, a self-contained in situ Underwater Particle Image Velocimetry was developed to measure the turbulence structure and the turbulent diffusion coefficient immediately above the profundal quagga mussel covered substrate …

Study On Dye-Sensitized Solar Cells Based On Tio2 Composite Nanomaterials, Cuiping Kang, Muhammad Aqeel Ashraf, Yung-Tse Hung

Civil and Environmental Engineering Faculty Publications

With the continuous development of nanomaterials, how to improve the conversion efficiency of DSSCs has been the focus of scholars. Nano-TiO2 material is a wide bandgap semiconductor with a bandgap of 3.2eV. It exhibits good performance in dye adsorption, charge separation, electron transport, etc., and has good chemical stability and strong acid and alkali resistance. Therefore, it was always the material of choice for the preparation of photoanodes. In this paper, different thicknesses of TiO2 NRs barrier layers were prepared on FTO substrates by solvothermal method and two-step spin coating method, and their electrochemical and photoelectric properties were tested by …

Silver-Based Microbial Check Valve For Spacecraft Potable Water Systems, Tanner Burns

Chemical Engineering Undergraduate Honors Theses

As human space exploration increases, the development of a more efficient potable water treatment system suited for spacecraft becomes crucial. This Waste-management Education Research Consortium (WERC) challenge was designed to explore the viability of microbial control through the utilization of silver ions as a biocide for possible integration into the Tranquility Node 3 water purification system aboard the International Space Station (ISS). Current systems using iodine risk causing hyperthyroidism from overexposure; however, silver can be safely ingested without this side effect. After researching silver delivery methods including electrochemical ion production, controlled release, or a combination of the two, our team …

Defining Boat Wake Impacts On Shoreline Stability Toward Management And Policy Solutions, Donna Marie Bilkovic, Molly M. Mitchell, Jennifer Davis, Julie Herman, Elizabeth Andrews, Angela King, Pamela Mason, Navid Tahvildari, Jana Davis, Rachel L. Dixon

Civil & Environmental Engineering Faculty Publications

Coastal economies are often supported by activities that rely on commercial or recreational vessels to move people or goods, such as shipping, transportation, cruising, and fishing. Unintentionally, frequent or intense vessel traffic can contribute to erosion of coastlines; this can be particularly evident in sheltered systems where shoreline erosion should be minimal in the absence of boat waves. We reviewed the state of the science of known effects of boat waves on shoreline stability, examined data on erosion, turbidity, and shoreline armoring patterns for evidence of a response to boat waves in Chesapeake Bay, and reviewed existing management and policy …

A Comparison Of The Army Corps Of Engineers Hydrologic Modeling System And Autodesk Storm And Sanitary Analysis For Hydraulic And Hydrologic Analysis And Design, Foster Josef Heifetz Campbell

Master's Theses

Hydrological and hydraulic effects of urban development is one of the key issues of study for improved water management. The addition of impervious surfaces to once pervious land and re-routing open channels and flow paths can cause flooding or declining water levels within a watershed. Many studies of these issues have found that there can be multiple factors causing hydrological and hydraulic impacts, and it can be hard to analyze and develop effective solutions without appropriate drainage software packages. However, there are multiple software packages available for use, and determining the correct one to use for a specific challenge can …

Optimizing Hydrogen Sulfide Removal And Biogas Production Using The Water Wash Method, Brian Leightner

Theses and Dissertations

Biogas forms from decomposing organic material in agricultural digesters, landfills, and wastewater treatment plant digesters. Biogas is mostly composed of methane, and can be used as a carbon-based fuel. Microorganisms that consume organics in these waste streams also produce hydrogen sulfide (H2S) as part of the biogas, in varying trace amounts. H2S is corrosive to engines and pipes for machinery, a human health hazard when inhaled, and an aquatic hazard when dissolved in water. Water washing is an absorption process that dissolves hydrogen sulfide and other water soluble compounds in this process and carries it away from the gas, thereby …

Using Tio2 To Optimize The Photocatalytic Degradation Of Kraft Black Liquor Using Response Surface Methodology, Zihan Wang

Major Papers

The Canadian pulp and paper industry has been concerned with reducing annual emissions of pollutants into water bodies, air and landfills. Black liquor is a major byproduct from pulp mills such as Kraft. Black liquor is utilized in boilers to produce steam and electricity. Black liquor is a low-value chemical and researchers have employed thermal and chemical processes to produce products such as oils, adhesives, and dispersants. In recent years, photocatalysis has become an alternative to degrade black liquor into short chain carbon chemicals.

This study aims to optimize the performance of black liquor photocatalytic degradation using the TiO_{2 …}

Modeling Response Of Water Quality To Land-Use And Climate Change In Lake Auburn, Me, Nicholas Messina

Electronic Theses and Dissertations

Lake Auburn, Maine, USA, is a historically unproductive lake that has experienced multiple algal blooms since 2011. The lake is the water supply source for a population of ~60,000. We modeled past temperature, and concentrations of dissolved oxygen (DO) and phosphorus (P) in Lake Auburn by considering the watershed and internal contributions of P as well as atmospheric factors, and predicted the change in lake water quality in response to future climate and land-use changes. A stream hydrology and P-loading model (SimplyP) was used to generate input from two major tributaries into a lake model (MyLake) to simulate physical mixing, …

Innovating Green Stormwater Infrastructure For Nutrient Management: Long-Term Field And Modeling Studies Of Conventional And Modified Denitrifying Bioretention Systems, Emma V. Lopez-Ponnada

USF Tampa Graduate Theses and Dissertations

Urban stormwater and nutrient management are increasingly important topics to address globally, as coastal urbanization increases, disturbing the natural landscape, hydrology, and water quality. Untreated urban stormwater runoff carries pollutants that enter our waterways, such as rivers and marine environments, which serve as drinking water sources, recreational sites, and locations for economic livelihood. One pollutant and nutrient of concern for water quality is reactive nitrogen (N). Since pre-industrial time, reactive nitrogen has doubled from human activity. When found in excess in waterways, nitrogen causes an overabundant growth of algae, which can result in eutrophic and hypoxic conditions, impacting ecosystems, human …

High Ammonia Strength Wastewater Treatment Using Algae, Bacteria And Ion Exchange, Nadezhda Zalivina

USF Tampa Graduate Theses and Dissertations

Nitrogen pollution has been considered one of the major problems of the 21st century. Discharge of nitrogen from improperly treated wastewaters into surface water bodies causes eutrophication and hypoxia, which results in significant environmental, public health and economic damages. In addition to the incoming flow, wastewater treatment plants generate internal highly concentrated ammonium streams, such as anaerobic digestion sidestream. As a current practice, sidestream without prior treatment is returned to the head of the plant, which increases the total incoming nitrogen load by 20-30% and often exceeds the treatment capacity. The most commonly used conventional biological nitrogen removal processes are …