Civil & Environmental Engineering Masters Theses

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Analysis and Evaluation of the Pedestrian Hybrid Beacon in School Zones
(North Dakota State University, 2010) Bittner, Michael Howard
Meeting dual objectives of pedestrian safety and motorist convenience at pedestrian crossings in school zones is an important and continuing challenge for all local communities. Pedestrian safety is influenced by pedestrian delays as well as motorist compliance of controls. Motorist convenience is influenced by the delay experienced by drivers. Conventional crosswalk control devices such as marked crosswalks and pedestrian signals are not always adequate or efficient in balancing these two crucial but conflicting objectives. The 2009 edition of the Manual on Uniform Traffic Control Devices (MUTCD) has paved the way for the use of a brand new crosswalk control device known as the pedestrian hybrid beacon (PHB). Previous research has provided evidence of this device's effectiveness in the area of motorist compliance and reduced motorist delay compared to traditional pedestrian signals. No prior research has been conducted on the PHB in the school zone context or on children pedestrians in general. This research has two objectives. The first objective was to analyze MUTCD Warrant 5 standards, which are designed for pedestrian signals in school zones, and the new PHB standards. This analysis will use pedestrian volume, vehicle volume, and gap availability on different test locations to conduct a comparative analysis of the two sets of standards. The purpose of this objective is to determine the transferability of the new MUTCD PHB standards in the school zone context. The second objective of this research was to evaluate three crosswalk control devices; marked crosswalks, pedestrian signals, and PHBs, for their ability to effectively address pedestrian safety and motorist convenience at school crossings. It was found that the PHB performed significantly better than traditional marked crosswalks but not markedly different than conventional pedestrian signals in the ability to balance the objectives of pedestrian safety and motorist convenience. The absence of improvements in performance of the PHB when compared to the pedestrian signal can be attributed to the fact that only 8.8% of motorists correctly utilized the PHB at the test location in Fargo, North Dakota. The most significant contribution of this thesis was finding that the current PHB standards in MUTCD are not transferable to the school zone context. For PHBs to be considered a viable option for engineers designing and controlling school crosswalks, it is essential that the MUTCD have school zone specific standards or guidance. The analysis carried out in this research provides insights into how such standards can be established and applied.
An Investigation of the Kerogen-Mineral Interactions in Green River Oil Shale
(North Dakota State University, 2010) Alstadt, Kristin Nadiene
Green River oil shale contains minerals, kerogen, and bitumen and yields a significant amount of oil upon heating. Kerogen is the insoluble organic remains found in sedimentary materials. It is a precursor to crude oil and is one of the most abundant forms of carbonaceous materials on earth. The richest oil shale deposits in the world are found in the Green River Formation located in the states of Utah, Wyoming and Colorado in the United States with the potential to be a major national resource. Current extraction methods involve heating the shale to high temperatures in order to decompose and evaporate the shale oil. This method is very inefficient due to tremendous energy requirements and is environmentally unfriendly. Thus, the extraction of kerogen is commercially not viable in the United States at this time. My research at North Dakota State University has been focused on understanding how the kerogen is "locked" in the surrounding mineral matrix. The research involves experimental and modeling studies aimed at evaluating the molecular interactions in the oil shale. The focus of my study has been on the in situ chemical composition, mechanical properties, and the physical location of kerogen in Green River oil shale. Fourier Transform Infrared (FTIR) studies have been conducted using the photoacoustic step-scan method to investigate the molecular nature of light and dark colored areas of the oil shale core. This technique provided the means for in situ investigation of kerogenmineral interactions. Results show that light colored oil shale has a high kerogen content with spectra similar to that of isolated kerogen while dark colored oil shale has more mineral components. Kerogen band shifts occurred indicating interactions on the molecular scale between kerogen and the surrounding minerals. Scanning Electron Microscope (SEM) studies were performed in order to obtain information on the size and layout of pores, minerals, and kerogen in the shale. Energy Dispersive Spectroscopy (EDS) performed ort light and dark colored samples indicate that the light colored oil shale contains more kerogen associated with the minerals quartz, clay, and potassium-feldspar. Dark oil shale samples contained kerogen, clay, dolomite, calcite, pyrite, and analcite. SEM images perpendicular to the bedding plane of cross-sectional polished oil shale samples showed orientated layers and elongation consistent with compression over time. The absence of large kerogen regions in SEM images and nanoindentation results suggest that Green River kerogen is on the scale of tens of nanometers and is in close proximity to oil shale minerals. The mechanical properties of kerogen and oil shale minerals were found using nanoindentation techniques. Green River kerogen was found to have an elastic modulus of 9 GPa and hardness of 1 GPa.
Durability of Concrete Members Strengthened with CFRP Sheets under Harsh Environmental Conditions
(North Dakota State University, 2010) Hossain, Md. Mozahid
The deterioration of concrete structures 1s a maJor concern to the infrastructure community. Typical sources of deterioration may include aging,.incrcased service load, and environmental damage. Structural rehabilitation using carbon fiber reinforced polymer (CFRP) sheets has recently attracted attention to the infrastructure community because of the superior strengthening effects in comparison to conventional repair methods. The CFRP sheets may be bonded on the deteriorated concrete structure using bonding agents to enhance load-carrying capacity. The most important consideration in such a strengthening method may be the long term durability under harsh environmental conditions. Furthermore, premature debonding of bonded CFRP sheets may also cause significant losses of the strengthening effects. Although extensive research has been reported on the debonding mechanism of CFRP sheets, there is still lack of understanding on the durability of CFRPs subject to low temperature effects. This thesis presents some major findings of the durability performance of concrete members strengthened with CFRP sheets subjected to harsh environments.
Analyses of Highway Project Construction Risks, Performance, and Contingency
(North Dakota State University, 2010) Mohamed, Fahmy Diab
Past studies have highlighted the importance of risk assessment and management in construction projects and transportation industry, and have identified cost and time as the most important risks that transportation professionals want to understand and manage. The main focus of this study is to comprehensively analyze transportation construction risk drivers and identify the correlation of the significant risk drivers with project characteristics, cost growth, schedule growth, and project contingency. This study has adopted 31 relevant and significant programmatic and project-specific risk drivers from different past studies. These risk drivers have been analyzed and evaluated using survey responses from professionals in the context of highway transportation projects. Risk assessments including rating of the encountered risk drivers and their correlation with project characteristics have been carried out within the context of highway construction projects in the United States. Correlations of the construction project performance or risk measures, cost growth percentage, and schedule growth percentage, with the rating values of identified risk drivers values have enabled a better understanding of the impacts of risks and the risk assessment process for highway transportation projects. The impact of significant risk drivers on reported construction cost contingency amounts has also been analyzed. The purpose of this effort was to assess impact of ratings for cost impact, schedule impact, and relative importance of the identified risk drivers on contingency amounts. Predetermined method is the common way to calculate contingency amount in transportation projects. In this study parametric modeling has been used to analyze the relationship between predetermined contingency amounts in transportation projects with perceived risk rating values in order to understand how the expert judgments regarding risk ratings can be used in determination of contingency amounts.
Comparisons of Energy Dissipation in Structural Devices with Foundation Soil During Seismic Loading
(North Dakota State University, 2010) Saravanathiiban, Duraisamy Soundararajan
The effectiveness of structural energy dissipation mechanisms such as passive energy dissipation devices and base isolation methods used in seismic design depends on their capacity, ductility, energy dissipation, isolation, and self-centering characteristics. Though rocking shallow foundations could also be designed to possess many of these desirable characteristics, current seismic design codes often avoid nonlinear behavior of soil and energy dissipation beneath foundations because of concerns about permanent deformations at foundation level. This thesis compares the effectiveness of energy dissipation in foundation soil with structural energy dissipation devices during seismic loading. Numerical simulations of structures with and without energy dissipation devices were carried out to systematically study the seismic energy dissipation in structural elements and energy dissipation devices. The numerical model was validated using shaking table experimental results on model frame structures with and without energy dissipation devices. The energy dissipation in the structure, drift ratio, and the force and displacement demands on the structure are compared with energy dissipation characteristics of rocking shallow foundations as observed in centrifuge experiments, where shallow foundations were allowed to rock on dry sandy soil stratum during dynamic loading. The comparisons of results clearly indicate that foundation (rocking) energy dissipation mechanism is as efficient as structural passive energy dissipation devices. For the structures with energy dissipating devices, about 70% to 90% of the seismic input energy is dissipated by energy dissipating devices, while foundation rocking dissipates about 30% to 90% of the total seismic input energy in foundation soil (depending on static factor of safety). Inclusion of energy dissipating braces increases the base shear force transmitted to the structure, while normalized base shear forces transmitted to the foundation during rocking are smaller than those of the structures with energy dissipating devices because of the isolation effect of rocking foundations. If properly designed (with reliable capacity and tolerable settlements), adverse effects of foundation rocking can be minimized while taking advantage of the favorable features of foundation rocking, and hence they can be used as efficient and economical seismic energy dissipation mechanisms in buildings and bridges.
Filamentous Growth in Entrapped Microbial Cell Reactor Treating Wastewater
(North Dakota State University, 2010) Sathyaseelan, Vinodgnanadrepan
The overgrowth of filamentous microorganisms in wastewater treatment systems is a common adversary condition leading to foaming, poor sludge settling problems, and reduction in organic removal efficiency. Entrapped microbial cell reactors have been investigated for their uses in wastewater treatment. However, their susceptibility to filamentous growth is not known. The objective of this study is to investigate the filamentous growth and its effect on the treatment performance of an entrapped microbial cell system treating wastewater. A typical activated sludge wastewater treatment system was included for comparative purpose. Both systems were operated at the same operating conditions using synthetic wastewater. Four different hydraulic retention times (HRT) (9, 6, 3, 1.5 hours), three different dissolved oxygen (DO) concentrations (2, 4.5 and 5.7 mg/1), and three different influent chemical oxygen demand (COD) concentrations ( 120, 206 and 300 mg/I) were investigated. Results showed that DO and organic loading rate (COD/HRT) did not have any effect on the organic (soluble COD and soluble biochemical oxygen demand at 5 days) removal efficiencies at high and medium HRT (9 and 6 hours), even when there was excessive filamentous growth in the entrapped microbial cell reactor. The organic removal efficiencies of the activated sludge system dropped for some cases at high and medium HRT because of excessive filamentous overgrowth. At low HRT (3 hours), there was abundant filamentous growth and a drop in the organic removal efficiencies in the entrapped microbial cell reactor. To determine the reason (between HRT and filamentous abundance) for the decreases in organic removal efficiencies by the entrapped microbial cell system at the low HRT, a very low HRT of 1.5 hours was applied. DO and organic loading rate did not affect organic removal efficiencies of the entrapped cell reactor. Reduction of the filamentous microorganisms was attempted by chlorination using sodium hypochlorite. Three different chlorine dosages, I, 0.25 and 0.50 g NaOCl/d, were applied. The dosage of 0.25 g NaOCl/d was found to be very effective in controlling the filamentous overgrowth in the entrapped microbial cell reactor. The reduction of filamentous organisms by chlorination did not result in improved organic removal efficiencies, suggesting that the very low HRT rather than the abundance of filamentous organisms was responsible for the poorer performance of the reactor. A cell morphology and organelle analysis indicated Sphaerotilus natans as the most frequently observed filamentous microorganism in the entrapped microbial cell reactor. A thick layer of biofilm was also observed on the entrapment matrix. The biofilm did not affect the performances of the reactor. These results suggested that the entrapped microbial cell reactor is subjected to filamentous overgrowth, but it has no effect on the performances of the reactor.
Modeling and Analysis of Impacts of Right-Tum Lane Lengths
(North Dakota State University, 2010) Chevuri, Pavan Kumar
Tum lanes have been studied for several decades, with focus being on left-tum lanes and for urban areas. The need for right-tum lanes has been studied using the impact of such tum lanes on both safety and operational efficiency. However, the impacts of different right-tum lane lengths have not been studied well. The determinations of righttum lane lengths have been based primarily on the deceleration of the right-turning vehicles, which happens to be one of the many factors that should influence such decisions. In this study the impacts of the right-tum lanes on two-lane roads with no controls on major roads have been modeled and analyzed. In particular, the impacts on the space mean speed and the delays have been studied using both the analysis of field data from several intersections around Minnesota and the analysis of the results from simulation models developed using CORridor SIMulation (CORSIM®)
Quantification of the Influences of Subsurface Uncertainties on Seismic Behavior of Shallow Foundations
(North Dakota State University, 2011) Kayser, Mohammad Feroz Ahmed
The properties of geomaterials are uncertain. These uncertainties not only affect the dynamic behavior of the geomaterials, but also significantly influence the complex nonlinear dynamics between the soil, foundation, and the structure (dynamic soilfoundation- structure interaction - SFSI). However, current civil engineering approach in incorporating the effects of SFSI on the seismic behavior of structures is still largely deterministic without considering uncertain geomaterial properties. The objectives of this research are to characterize the uncertainties in soil properties m a probabilistic framework and to quantify their effects on dynamic soil-foundation system behavior during seismic loading. The research methodology includes systematic propagation of uncertainties in soil properties through soil-foundation interface to the dynamic behavior of the structure during seismic loading. A recently developed Contact Interface Model (CIM), to model the soil-foundation system behavior during seismic loading, has been used in numerical simulations. To study the sensitivity of the response of the soil-foundation system to the random input parameters, probabilistic analyses have been carried out using Tornado Diagram analysis, Spider Plot analysis, First Order Second Moment (FOSM) analysis, and small scale Monte-Carlo simulations. Results obtained from the probabilistic numerical simulations indicate that ultimate moment capacity of the soil-foundation system during seismic loading is more sensitive to the uncertainty in the applied vertical load on the foundation than the uncertainties in soil properties. Since the uncertainty in applied vertical load is considerably smaller than the uncertainties in soil properties, the ultimate moment capacity of shallow foundation is predictable with reasonable accuracy. Energy dissipation beneath the foundation mainly depends on the applied vertical load and initial vertical stiffness of the foundation, while initial vertical stiffness of the foundation and rebounding ratio were found to contribute the most to the settlement of the foundation. The rotation of the foundation is more sensitive to the shaking intensity than uncertainties in soil properties.
Evaluating the Effects of Rail Preemption Strategies on Highway Safety and Operations
(North Dakota State University, 2011) Bratlien, Andrew Lee
Previous research related to signal preemption near highway-rail grade crossings has emphasized safety considerations, which are paramount due to the severity of potential train-vehicle collisions. The purpose of this research was to quantify the safety and efficiency implications of several common preemption strategies using the conditions in a small urban context. The research evaluates several important characteristics of rail preemption, including track clearance time, advance preempt time, and dwell cycle strategy, particularly with regard to surface street operational efficiency, that current traffic engineering practice do not adequately address. The context and preemption strategies were modeled using simulation software VISSIM. The results identified two separate and potentially serious safety issues related to the interaction of advance preempt time, track clearance time, and existence of four-quadrant gates at railroad crossing. In addition, the research also highlighted the negative effect of excessive track clearance time and dwell cycle on adjacent surface street operations.
Time-dependent Behavior of Various FRP Composites for Structural Applications
(North Dakota State University, 2011) Khan, Md. Fuad Hassan
This thesis represents the long-term behavior of fiber reinforced polymer (FRP) materials for structural applications. FRP composites consist of high-strength fibers embedded in an epoxy resin. The long-term investigations include i) pultruded glass FRP (GFRP) beams subjected to sustained loads and cold temperature and ii) reinforced concrete beams strengthened with near-surface mounted (NSM) carbon FRP (CFRP) strips. For the first phase, test parameters include the variation of sustained intensities and temperature. The flexural behavior of the long-term beams is studied through a combined experimental and numerical approach, including load-carrying capacity, failure mode, creep response, and material degradation. Some material parameters that are crucial for practical applications are suggested using a regression analysis. A finite element model is developed to predict the behavior of GFRP beams. An analytical model is also proposed to estimate the long-term behavior of GFRP composites for structural applications. For the second phase, test parameters include the variation of sustained intensities, CFRP strengthening schemes and bonding agents. The short-term beams are loaded both monotonically and cyclically whereas the long-term beams are loaded only monotonically. The flexural behavior of all beams is studied through an experimental investigation, including load-carrying capacity, failure mode, creep response, and material degradation.
Experimental Studies on Infiltration/Soil-Water Movement Processes and Green-AMPT Modeling
(North Dakota State University, 2011) Sande, Leif Andrew
Experimental studies on infiltration/soil-water movement processes are vital to better understanding movement of soil-water in the vadose zone. The objective of this experimental research was to investigate infiltration/soil-water movement processes utilizing laboratory experiments and computer modeling. Small scale laboratory soil box infiltration experiments were conducted and utilized for the improved parameterization of the Green-Ampt (GA) saturated moisture content parameter to produce an effective moisture content parameter (Be) for utilization in a modified GA model. By incorporating ⊖e values into GA modeling, modeling results showed greatly improved wetting front prediction across different soil conditions. A new soil packing method was proposed for replicating complex microtopographical surfaces with uniform bulk densities in laboratory soil box experiments which proved efficient and effective at accomplishing both objectives. A rainfall simulator and an instantaneous-profile laser scanner were used to simulate rainfall and quantify surface microtopography for experiments. The results clearly show the effect of microtopography on infiltration and soil-water movement characteristics. This offers valuable insight into infiltration/soil-water movement processes as affected by different soil and surface microtopographic conditions.
Alginate Encapsulated Nanoparticle-Microorganism System for Trichloroethylene Remediation
(North Dakota State University, 2012) Shanbhogue, Sai Sharanya
Nanoscale zero-valent iron (NZVI) particles were encapsulated in calcium alginate capsules for application in environmental remediation. TCE degradation rates for encapsulated and bare NZVI were similar indicating no adverse effects of encapsulation on degradation kinetics. Microorganisms were separately encapsulated and used along with encapsulated NZVI and co-encapsulated in calcium alginate capsules. Batch experiments were performed to test the efficacy of the combined iron-Pseudomonas sp. (PpF1) system. The combined system removed 100% TCE over the first three hours of the experiment followed by 70% TCE removal post TCE re-dosing. Complete reduction of TCE was achieved by NZVI between 0-3 h and the second phase of treatment (3-36 h) was mostly achieved by microorganisms. Experiments conducted with co-encapsulated NZVI-D.BAV1 achieved 100% TCE removal. During the first three hours of the experiment 100% TCE removal was achieved by NZVI, and 100% removal was achieved post re-dosing where D.BAV1 accomplished the treatment.
A Comparative Study of Nitrification in Fargo and Moorhead Distribution Networks
(North Dakota State University, 2012) Portlock, Daniel
Nitrification in water distribution networks has become a growing concern for water supplies in the United States. The use of chloramines as a disinfectant in distribution pipe networks has become increasingly popular to reduce the disinfectant byproducts that are formed with free chlorine. In chloraminated systems there is potential for nitrification to occur because it reduces chloramine residuals. As chloramines decompose in the network, ammonia is released. Nitrifiers oxidize ammonia into nitrites, which react with chloramines resulting in its further reduction. As this cycle continues, chloramines will be consumed faster in the network, causing regrowth of heterotrophic bacteria. A study was conducted to compare the Fargo and Moorhead distribution networks for the occurrence of nitrification and their potential to deteriorate water quality. Each distribution network was analyzed independently for variations in operational conditions and water quality parameters that can serve as indications of nitrification in a distribution network.
Influence of Molecular Interactions on Elastic Properties and Oxygen Diffusion in PolyButylene Terephthalate Polymer: A Molecular Dynamics Study
(North Dakota State University, 2012) Raviprasad, Muniyamuthu
In most barrier applications, both mechanical and diffusion properties of the material are important. In this thesis the evaluation of molecular mechanisms responsible for the enhanced elastic properties of Polymer Clay Nanocomposites (PCNs) and the molecular mechanisms of Oxygen diffusion in PolyButylene Terephthalate polymer are presented. Interaction energy between PCN constituents, conformational changes of polymer, interaction energy between Oxygen molecule and polymer, rate of Oxygen and Oxygen diffusion coefficient are evaluated. Molecular simulation studies of PolyButylene Terephthalate (PBT) clay nanocomposite and Nylon6 clay nanocomposite show that a higher crystallinity polymer such as PBT would require higher attractive and repulsive interactions with organic modifier in order to make significant change in the crystallinity of PBT in the nanocomposite and in turn enhance the elastic modulus and hardness. Molecular interactions energy between Oxygen molecule and polymer, change in polymer conformation caused by thermal energy assist the Oxygen molecule to diffuse through polymer.
Characterization of Surface Microtopography and Determination of Hydrotopographic Properties
(North Dakota State University, 2012) Chi, Yaping
Spatial characterization of surface microtopography is important in understanding the overland flow generation and the spatial distribution of surface runoff. In this study, fractal parameters (i.e., fractal dimension D and crossover length l) and three hydrotopographic parameters, random roughness (RR) index, maximum depression storage (MDS), and the number of connected areas (NCA), have been applied to characterize the spatial complexity of microtopography. Clear and meaningful relationships have been established between these parameters. The RR was calculated as the standard deviation of the processed elevation, and the fractal parameters were calculated with the semivariogram method. The puddle delineation program was applied in this study to spatially delineate soil surface and to accurately determine MDS and NCA. It has been found that fractal parameters can better characterize surface microtopography. More importantly, fractal and anisotropic analyses can help to better understand the overland flow generation process.
Initial Swelling Mechanism of Expansive Clays: A Molecular Dynamics Study
(North Dakota State University, 2012) Srinivasamurthy, Lakshmikanth
Expansive soils are widely found in many parts of the world. Highly active smectite clay mineral Montmorillonite is the major constituent in these clays and can expand or contract up to 15 times of their original volume. Constrained swelling exert large amount of stress causing damage to structures, pavements etc. These clays are also used as barrier materials, Nano-materials in polymer clay Nano composites and drug delivery systems. Several factors influence the swelling potential such as water content, density, voids, electrolyte content and cation exchange capacity. However, molecular scale mechanisms that control swelling behavior in these clays need to be understood. Objectives of this research are to provide an insight into mechanisms that result in swelling of these clays. Molecular modeling is used to build and study solvation of Na-Montmorillonite system. Trajectories of water molecules are captured and the evolutions of interaction energies with swelling are calculated.
Warm Mix Asphalt Processes Applicable to North Dakota
(North Dakota State University, 2012) Saboori, Arash
Warm mix asphalt (WMA) represents a group of technologies that allows production of asphalt mixtures at lower temperatures compared to traditional hot mix asphalt (HMA). This results in less fuel consumption and reduction in CO2 ¬and fumes emission. This research was conducted in order to provide North Dakota department of transportation (NDDOT) with a thorough study on state of the practice of WMA in USA and compare WMA performance with HMA. Extensive literature study was conducted, collecting reports and field experiment data from DOTs of states with climate similar to ND. Viewpoints of experts in the field were collected and analyzed using a comprehensive survey. These were added to analysis of collected data on WMA performance. The research results suggest using foaming processes (Double Barrel Green in particular) and chemical additives (Evotherm in particular) at this early stage with guidelines for modifications in WMA specification and testing compared to HMA.
Functionality of a Damaged Steel Truss Bridge Strengthened with Post-Tensioned CFRP Tendons
(North Dakota State University, 2012) Brunell, Garrett Floyd
This research program investigates the performance of a steel truss bridge when subjected to both localized web damage and a subsequent post-tensioned strengthening approach. The investigation utilizes a combined approach involving an experimental scale model bridge and a numerical computer model generated using the commercial finite element software RISA 3-D. The numerical model is validated using test data and further extended to parametric studies in order to investigate the theoretical load rating, strain energy, load redistribution, mode shapes and frequency of the bridge for control, damaged and strengthened states. The presence and severity of damage are found to significantly influence the global safety and reliability of the bridge. Also, higher order modes are more susceptible to changes in shape and frequency in the presence of damage. A recovery of truss deflection and a reduction of member forces are achieved by the proposed strengthening method.
Clay Fluid Interactions in Montmorillonite Swelling Clays: A Molecular Dynamics and Experimental Study
(North Dakota State University, 2012) Patwary, Md Zillur R.
Swelling clays cause tremendous amounts of damage to infrastructure. For the effective prevention of detrimental effects of these clays, and to optimize the beneficial properties for industrial applications it is necessary to clearly understand the fundamental mechanisms of swelling of clays. In this study, we studied the effect of fluid polarity on swelling and flow properties of swelling clays using molecular modeling and experimental technique for bridging the molecular level phenomenon of these clays with microstructure change, particle breakdown and macro scale swelling and flow properties. A wide range of fluids (Dielectric Constant 110 to 2.4) were used, those are also commonly present in landfill leachates. We were able to tie the properties of swelling clays at different length scales. Then, we simulated the solvation of clay sheets, studied the effect of discrete charge distribution, contribution of edge charges on swelling clays and discussed some fundamental assumptions associated with double layer theories.
Identifying Causes of Dissolved Oxygen Depletion and Determination of Sediment Oxygen Demand in the Souris River
(North Dakota State University, 2013) Baker, Matthew Ernest
The Upper Souris River was placed on the Environmental Protection Agencies (EPA) impaired waters list for low dissolved oxygen (DO). A Total Maximum Daily Load (TMDL) study was conducted to determine possible causes of DO depletion. From sampling and site visits it was determined nonpoint sources contributed the majority of organic loadings to the Upper Souris River. Through preliminary testing, it was determined that sediment oxygen demand (SOD) played a key role in depleting DO levels during winter months and required further investigation. River profile surveying, water quality sampling, and laboratory testing of SOD were carried out to determine parameters required for water quality modeling. SOD tests were conducted to determine impacts of sediment organic contents and temperature on SOD rate. Sediment oxygen demand rates ranged from 0.37 to 1.22 g O2/m2/d. The QUAL2K model was calibrated to simulate DO variations along the study reach under ice covered conditions.

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