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The Role Of Nitrification And Denitrification In Successful Cultivation Of Oxygenic Photogranules For Wastewater Treatment, Kristie Stauch-White

Environmental & Water Resources Engineering Masters Projects

Oxygenic photogranules (OPGs) are compact, spherical, self-immobilizing biofilms in the form of dense aggregates of microorganisms with a predomination of filamentous cyanobacteria cultivated from photoilluminated activated sludge. In this study, aerobic and anaerobic nitrogen transformation processes occurring simultaneously within OPGs, during both successful and unsuccessful cultivations, were examined. Chemical analyses including ammonium, nitrate, and nitrite concentrations at the beginning and periodically during OPG cultivations indicated nitrogen transformations occurring during successful cultivations. Additionally, qPCR studies revealed that successful cultivations supported a greater relative abundance of cyanobacteria, nitrifying, and denitrifying populations during the cultivation period. Dissolved oxygen microprofiles within a successfully cultivated …

Analyzing Streamflow Forecasts In The Context Of System Performance: A Case Study Of The City Of Baltimore Water Supply, Alexandra Mcintyre

Environmental & Water Resources Engineering Masters Projects

A major challenge confronting water suppliers is how to best incorporate emerging forecasting technologies into their drought management operations. The need for drought plans that make use of proactive drought mitigation actions is particularly pressing as climate change is expected to cause more frequent and severe droughts in the near future. This research evaluates streamflow forecast skill in the context of drought planning. The City of Baltimore’s water supply system serves as a case study. Forecasts generated by the National Oceanic and Atmospheric Administration (NOAA) and the National Weather Service’s Middle Atlantic River Forecast Center (MARFC) are integrated into a …

Transit Preferential Treatments At Signalized Intersections: Person-Based Evaluation And Real-Time Signal Control, Yashar Zeiynali Farid

Doctoral Dissertations

Efficient public transportation has the potential to relieve traffic congestion and improve overall transportation system performance. In order to improve transit services, Transit Preferential Treatments (TPT) are often deployed to give transit vehicles priority over other vehicles at an intersection or along a corridor. Examples of such treatments are exclusive bus lanes, queue jumper lanes, and signal priority strategies. The objective of this study is threefold: 1) perform a person-based evaluation of alternative TPTs when considered individually and in combination, 2) develop a bus travel time prediction model along a signalized arterial, and 3) develop a real-time signal control system, …

The Fate Of Haloacetonitriles In Drinking Waters, Yun Yu

Doctoral Dissertations

The fate of HANs in drinking waters from their precursors in natural waters to their degradation products in consumers’ tap were systematically investigated in this study. Combined amino acids were proved reactive with chlorine to form DCAN under typical drinking water conditions. However, the rate of DCAN formation from bound aspartyl residues was much slower compared to free aspartic acid. The key to DCAN formation from combined amino acids was a chlorine-induced peptide degradation process, which slowly degraded the peptide backbone to continuously produce reactive amine functional groups at the N-terminal end. Particularly, when an N-terminal aspartyl residue …

Detailed Study Of Integral Abutment Bridges And Performance Of Bridge Joints In Traditional Bridges, Brooke H. Quinn

Doctoral Dissertations

Integral Abutment Bridges (IABs) are jointless bridges in which the superstructure is cast monolithically with its substructure. Eliminating expansion joints from the superstructure reduces corrosion of bridge elements that typically result from leaking joints in traditional bridges. IABs have proven to be cost effective for both construction and life-cycle analysis. As a result, they are the standard single span highway bridge of choice by the majority of State Departments of Transportation (DOTs) across the country. Despite the widespread use of these bridges, there are no uniform guidelines in place. Factors such as pile orientation, design assumptions, maximum span length, skew …

Integrated Urban Metabolism Analysis Tool (Iumat), Nariman Mostafavi

Doctoral Dissertations

A number of tools are available today for simulating different aspects of urban activity, but these efforts are fragmented and do not effectively reflect the interrelationships between very diverse groups of urban sectors and resource flows. There is a critical need for robust and reliable urban metabolism analysis tools that integrate socio-economic elements of urbanization and physicality of the built environment into evaluating sustainability in cities. This dissertation outlines the development of an Integrated Urban Metabolism Analysis Tool (IUMAT) that dynamically measures the environmental impacts of land cover, transportation, and consumption of energy, water and materials employing a holistic framework. …

Predictive Modeling Of Riverine Constituent Concentrations And Loads Using Historic And Imposed Hydrologic Conditions, Mark Hagemann

Doctoral Dissertations

This research was principally concerned with the task of quantifying dissolved and suspended constituents carried in river water when direct measurements are not available. This is a question of scientific and societal relevance, and one with a long history of study and a great deal of remaining difficulty. The traditional approach to estimating these quantities, linear regression models (LMs), suffers from poor flexibility and high subsequent bias in many applications. This research applied semiparametric generalized additive models (GAMs), a more flexible class of regression models, evaluated their performance in various locations and conditions, and applied them in a proactive modeling …

The Stability Of Ferrate(Vi) In Water And Its Impacts On Disinfection Byproduct Precursors, Yanjun Jiang

Doctoral Dissertations

Ferrate has been proposed as an alternative pre-oxidant in drinking water treatment for many years. Despite extensive studies that examined ferrate oxidation of specific contaminants, little research has been done on the impacts of ferrate in raw waters that include natural organic matter (NOM) and bromide, and that are also treated with coagulants and chlorine. The future of ferrate as a potable water treatment chemical depends on its ability to achieve adequate disinfection while minimizing the formation of disinfection byproducts (DBPs) under these realistic scenarios. In this work, laboratory-scale treatment studies were conducted to (1) clarify the stability of ferrate …

Proactive Assessment Of Climate Change And Contaminant Spill Impacts On Source Water Quality, Lillian C. Jeznach

Doctoral Dissertations

Managing the water quality of surface drinking water sources has become an increasingly difficult task for water suppliers due to increased watershed urbanization and climate change. Changes in source water quality may affect public perceptions, treatment effectiveness, and ultimately costs to treat water to drinking standards. Although there are increased threats to current and future drinking water quality, current approaches to managing these threats are typically reactionary. Prior detailed modeling efforts of hypothetical events that may impair raw water quality allow for an understanding of constituent fate and transport, including potential maximum concentrations and travel times to the drinking water …

Live Load Distribution Factors For Horizontally Curved Concrete Box Girder Bridges, Mohammed Zaki

Masters Theses

Live load distribution factors are used to determine the live-load moment for bridge girder design when a two dimensional analysis is conducted. A simple, analysis of bridge superstructures are considered to determine live-load factors that can be used to analyze different types of bridges. The distribution of the live load factors distributes the effect of loads transversely across the width of the bridge superstructure by proportioning the design lanes to individual girders through the distribution factors.

This research study consists of the determination of live load distribution factors (LLDFs) in both interior and exterior girders for horizontally curved concrete box …

Modeling Choice Problems With Heterogeneous User Preferences In The Transportation Network, Mahyar Amirgholy

Doctoral Dissertations

Users of transportation systems need to make a variety of different decisions for their trips in the network, while their objective is to keep the generalized costs of their own trips minimized. In the transportation network, there is a diversity of different factors that can influence the decisions of the users, while the relative importance of these factors varies among the heterogeneous users with different trip purposes. Nonetheless, the cumulative result of the individual decisions of the users seeking to minimize their costs according to their own preferences leads to the user equilibrium condition in which no one can reduce …

Drought Management Using Streamflow Forecasts: A Case Study Of The City Of Baltimore Water Supply, Kathryn Booras

Environmental & Water Resources Engineering Masters Projects

This research investigates forecast skill in predicting the onset and severity of drought in the Susquehanna River Basin. Streamflow forecasts developed by the National Oceanic and Atmospheric Administration’s (NOAA’s) Mid-Atlantic River Forecast Center (MARFC) are incorporated with other key drought indices in an aggregate drought index to predict and classify drought severity and to trigger drought mitigation actions. Climate drought index parameters for the Susquehanna River Basin, such as the Standardized Precipitation Index (SPI), Days of Storage Remaining Index (DSR), and Palmer Drought Severity Index (PDSI), are evaluated by their ability to detect water supply droughts of record. Drought indicators …

Biogenic Organic Carbon Compounds In Air And Rain, Iman Hosseini Shakib

Environmental & Water Resources Engineering Masters Projects

Rainwater quality has not been an issue of concern until recent decades of increasing urbanization and industrialization. Therefore, the role of biogenic contamination sources has been always underestimated as generally, anthropogenic contaminants are thought to be responsible for rainwater quality deterioration. This study aims to find the sources and reasons of biogenic VOC emission into the air and their changes in the air. Also, transfer of biogenic VOCs into the rainwater and their abundance have been investigated. The effects of these biogenic VOCs on rainwater quality have been studied by sampling of two rain events in the University of Massachusetts …

Assessing The Economic And Flow Regime Outcomes Of Alternative Hydropower Operations On The Connecticut River's Mainstem, Luke Detwiler

Environmental & Water Resources Engineering Masters Projects

Hydropower provides a source of reliable and inexpensive energy, producing approximately 20% of the global energy supply, though it comes at a cost to riverine ecosystems. To maximize revenues, major hydropower facilities store and release water with respect to short-term changes in energy price, causing significant sub-daily flow regime alterations that impact downstream ecological communities. In the United States, the Federal Energy Regulatory Commission (FERC) is responsible for hydropower regulation and this is administered, in part, during periodic relicensing of existing facilities. The process of relicensing provides the opportunity to evaluate the goals and concerns of interested parties and evaluate …

Investigating Interactions Between Water And Society On A Global Scale: Econometric Analyses Of Hydroclimatic Variability And Water Policy, Hassan Furqan Khan

Environmental & Water Resources Engineering Masters Projects

INVESTIGATING INTERACTIONS BETWEEN WATER AND SOCIETY ON A GLOBAL SCALE: ECONOMETRIC ANALYSES OF HYDROCLIMATIC VARIABILITY AND WATER POLICY AUGUST 2016 HASSAAN FURQAN KHAN Directed by: Professor Casey M. Brown Water-related hazards such as floods, droughts and disease cause damage to an economy through the destruction of physical capital including property and infrastructure, the loss of human capital and the interruption of economic activities, like trade and education. The question for policy makers, however, is whether the impacts of water-related risk accrue to manifest as a drag on economic growth at a scale suggesting policy intervention. In this work, we use …

Hydrologic Modeling At Ungauged Locations In Support Of The Development Of A Vulnerability Ranking Protocol System For Road-Stream Crossing Infrastructure, Gordon Clark

Environmental & Water Resources Engineering Masters Projects

Recent tropical storms that have resulted in flood events with large economic impacts in the Northeastern US have catalyzed efforts to understand the complex interactions between human and natural systems. Specifically, the resilience of our transportation infrastructure to climate and the impact of our transportation systems on the aquatic environment are of significant interest on both the local and regional scales to state and federal agencies. It is important that new, innovative approaches be developed that consider both the robustness of our infrastructure today and its ability to cope with forecasted extremes due to climate change. Because few streams are …

Integrated Solar Technologies With Outdoor Pedestrian Bridge Superstructure Decking, Richard K. Racz

Masters Theses

Solar technology has been a major topic in sustainable design for many years. In the last five years, however, the solar technology industry has seen a rapid growth in installations and technological advances in cell design. Combined with a rapidly declining overall system cost, the idea of introducing solar technology into a wider range of applications is becoming a focus for engineers and scientists around the world. So many variables which alter solar energy production, such as the sun and surrounding environment, determine whether a solar design is beneficial. This thesis presents a bridge deck surface integrated with solar cells …

Developing An Ecological Sanitation Transect, Ian Kolesinskas

Masters Theses

A sanitation problem exists for people across the globe: basic human waste collection and treatment is inaccessible to much of the world’s population; and the status-quo gray infrastructure system of sanitation is unsustainable and unsuitable for widespread application. A paradigm shift is needed: this thesis makes the case for developing an Ecological Sanitation Transect to bring back the closed loop that connects consumption, waste excretion, sanitation, and food production. The Ecological Sanitation Transect is a synthesis of ecological sanitation, where human excreta is reused, and the urban transect, where development density is conceptualized along a continuum from rural to urban. …

A Vulnerability Framework For Assessing The Risks To Water Supply Systems Under Climate Uncertainty In The Urban Northeastern United States, Sarah Whateley

Doctoral Dissertations

The northeastern United States is not commonly considered a drought prone region. Yet there are increasing pressures on water utilities throughout the region that constrain their ability to supply reliable water. These include new constraints on water withdrawals and requirements to release additional water for ecological purposes. Finally, there is the emerging concern associated with climate change. The vulnerability of any particular system, however, is not easily assessed, as it is dependent on a variety of factors that go beyond simple changes in precipitation and temperature. These include the size of the watershed, the volume of storage, required releases, and …

Modeling Interactions Between Human Factors And Traffic Flow Characteristics, Chaoqun Jia

Doctoral Dissertations

To serve research needs for traffic flow model development and highway safety enhancement, we model interactions between human factors and traffic flow character- istics, this topic includes methods on collecting data, modeling impacts of parameters on flow, and calibrating parameters on observed data. An example of successful traf- fic data collection is NGSIM data, which contains location, speed, and acceleration information of vehicles. An algorithm was designed to match and extract vehicles’ trajectory records, and utilize the extracted information for pattern recognition of lane changing maneuvers. This algorithm reads records from an NGSIM data set, pick out vehicles executing lane …

Investigation Of Effluent Nitrogen Derived From Conventional Activated Sludge (Cas) And Biological Nutrient Removal (Bnr) Systems And Its Impact On Algal Growth In Receiving Waters, Heonseop Eom

Doctoral Dissertations

The main objective of this research was to evaluate the effects of effluent nitrogen from conventional activated sludge (CAS) and biological nutrient removal (BNR) processes on eutrophication in receiving estuaries. To investigate differences in effluent nitrogen from CAS and BNR processes, lab-scale wastewater treatment systems having identical influent were operated under controlled conditions. This reactor study showed that the BNR system decreased nitrogen discharge by removing dissolved inorganic nitrogen (DIN) from wastewater but generated more effluent dissolved organic nitrogen (DON) than did the CAS system. The transition of treatment conditions from anoxic to oxic within the BNR process facilitated the …

Adaptive Route Choice In Stochastic Time-Dependent Networks: Routing Algorithms And Choice Modeling, Jing Ding-Mastera

Doctoral Dissertations

Transportation networks are inherently uncertain due to random disruptions; meanwhile, real-time information potentially helps travelers adapt to realized traffic conditions and make better route choices under such disruptions. Modeling adaptive route choice behavior is essential in evaluating Advanced Traveler Information Systems (ATIS) and related policies to better provide travelers with real-time information. This dissertation contributes to the state of the art by estimating the first latent-class routing policy choice model using revealed preference (RP) data and providing efficient computer algorithms for routing policy choice set generation. A routing policy is defined as a decision rule applied at each link that …

Understanding Factors That Affect Microbial Fuel Cell Performance: Inoculum Characteristics And Methanogenesis, Joshua Jack

Environmental & Water Resources Engineering Masters Projects

Microbial fuel cells (MFCs) are a promising approach to wastewater treatment that use anode-respiring bacteria (ARB) to oxidize organic matter and generate electric current. Although these devices have great potential, MFCs are not yet commercialized primarily due to their low power output at pilot scale. Past studies have hypothesized power production may be largely limited by high internal resistances and competing microbial metabolisms (Logan et al., 2008).

The source of inoculum used to build MFC communities has been demonstrated to significantly influence cell resistance and microbial dynamics (Sun et al., 2008; Chae et al., 2008). Studies that have shown these …

Aging And Property Changes Of Clay Around Driven Piles, Hasian R. Zapata

Geotechnical Engineering Masters Projects

The purpose of this research was to determine how soil disturbance caused by the installation of piles (of differing types and geometries) in clay affect the short and long-term capacity of piles. Several types of piles were installed in lightly overconsolidated clay at three different test sites in Amherst, Massachusetts. Before and after pile installation, an in-situ testing program consisting of field vane shear tests was carried out around piles installed at one of the three testing sites. Undrained shear strength and water content profiles allowed for an approximate determination of changes in the behavior of the clay surrounding some …

Evaluating Roadway Cross-Sectional Design Elements And Its Impact On Driver Behavior Using A Driving Simulator, Bhavana Gongalla

Transportation Engineering Masters Projects

This research explores the relationship between the cross-sectional design elements and the impact on selected driver attributes such as speed profiles and lateral positioning. In this experiment a traditional collector type base roadway of 1.5 miles with 14 ft travel lane and 8 ft shoulder was modeled using a fixed base driving simulator. The base scenario was subsequently reconfigured with four different cross-sectional design with various elements within the same physical right-of-way. Specific design elements included, narrower lanes, bicycle lanes, raised center median and a curvilinear roadway profile. A within subject’s design of twenty participants who drove each of the …

A Simple One-Scale Constitutive Model For Static Liquefaction Of Sand-Silt Mixtures, Yang Liu, Ching-Shung Chang, Shun-Chuan Wu

Civil and Environmental Engineering Faculty Publication Series

Instability of liquefaction is one of the major reasons which results in the failure of earth structure such as dam. The present study focuses on the simulation of static liquefaction behavior for granular materials such as sand and sand-silt mixtures. Based on micromechanical analysis of inter-particle behavior, a simple one-scale model is proposed to simulate the stress-strain response of sand; then the proposed model is extended to simulate the sand-silt mixtures using the mixture theory combining the properties of sand and silt according to their proportions. Empirical expressions are introduced to fit the critical state strength and the location of …