Environmental Engineering Commons^™

Massive Spatiotemporal Watershed Hydrological Storm Event Response Model (Mhserm) With Time-Lapsed Nexrad Radar Feed, Changqing Song

Civil & Environmental Engineering Theses & Dissertations

Correctly and efficiently estimating hydrological responses corresponding to a specific storm event at the streams in a watershed is the main goal of any sound water resource management strategy. Methods for calculating a stream flow hydrograph at the selected streams typically require a great deal of spatial and temporal watershed data such as geomorphological data, soil survey, landcover, precipitation data, and stream network information to name a few. However, extracting and preprocessing such data for estimation and analysis is a hugely time-consuming task, especially for a watershed with hundreds of streams and lakes and complicated landcover and soil characteristics. To …

Catalytic Wet Air Oxidation Of Mono Azo Dye Orange Ii: Catalyst Selection, Reaction Kinetics, And Modeling, Pinar Ozdural

Civil & Environmental Engineering Theses & Dissertations

Wastewaters generated as byproducts of dyeing processes are not treatable with conventional methods. It has been estimated that among the 900,000 tons of different dyes produced annually in the world, approximately 10–15% are lost in wastewater streams during manufacturing and processing operations. Once in rivers and streams, dyes cause major problems, such as reducing light penetration, or displaying toxic effects on aquatic life. Therefore, it is essential that dyes are removed from wastewaters before being discharged into the environment.

This study focuses on the catalytic wet air oxidation (CWAO) of Orange II, a mono azo dye used in large amounts …

Adsorption Of Lead (Ii) Ions By Organosilicate Nanoporous Materials, Larry Keith Isaacs

Civil & Environmental Engineering Theses & Dissertations

As-synthesized organosilicate nanoporous (OSNP) materials HMS (hexagonal mesoporous structure) and MCM-41 were used as adsorbents for removal of lead (II) ions in laboratory batch and column studies. Mesoporous organosilicates were prepared from tetraethylorthosilicate (TEOS) and either an ionic (cetyltrimethyl-ammonium) or neutral (dodecylamine) surfactant. Batch reaction distribution coefficients for MCM-41 were K_D = 51.5 L/g (SD = 26.3) at 24 h and K_D = 73.7 L/g (SD = 40.5) at 7 d. OSNP lead (II) ion adsorption increased from pH = 3 until pH ca. 7.5 after which a sharp decrease in adsorption was noted. OSNP materials reflected a …

Analysis Of Ultraviolet Energy Distribution In Uv Disinfection Systems Using Monte Carlo Ray -Trace Method, Khoi Trung Nguyen

Civil & Environmental Engineering Theses & Dissertations

Determination of fluence rate in ultraviolet (UV) disinfection systems is a crucial part in evaluating disinfection efficiency of the systems. A robust Monte Carlo Ray Trace (MCRT) method has been developed to determine fluence rates in three-dimensional space of the systems. This is a statistical sampling method in which millions of random light energy bundles are simulated from the axis of each UV lamp and traced through the system until their energies reduce to a minimum threshold level. Inherent phenomena including refraction through quartz tubes, specular reflection at quartz tube surfaces, and absorption by quartz and water, along with specific …

An Analysis Of Indicator Organism Suitability For Lower James And York Rivers, Rhonda Ashonti Ford

Civil & Environmental Engineering Theses & Dissertations

The primary objectives of this thesis are (1) determine if the proper indicator organism is being utilized to determine the bacterial water quality in the State of Virginia. (2) If other environmental factors can predict the bacterial water quality. The current indicator organism of choice for bacterial water quality of waters in the State of Virginia is enterococci, for estuarine and brackish waters. E. coli is the indicator organism of choice for fresh waters in Virginia.

The study concluded (1) Enterococci are the best indicator organism for beaches located in the Hampton Roads Harbor and the Lower James River. (2) …

Halonitromethane Treatment Using Advanced Oxidation Process: Rates, Mechanisms And Kinetic Modeling, Stuart Kirkham Cole

Civil & Environmental Engineering Theses & Dissertations

Halonitromethanes (HNMs) are low molecular weight halogenated disinfection-by-products (DBPs) found to be formed during ozonation, chlorination, or chloramination of waters containing natural bromide ion and nitrogenous organic matter. This work identifies the absolute rate constants for the oxidative hydroxyl radical (•OH) and reductive hydrated electron e^- _aq extinction of HNM compounds. Three forms of HNMs included in this study are the chlorinated, brominated, and mixed halogenated compounds. Electron pulse radiolysis and transient absorption spectroscopy were used to measure •OH and e^- _aq radical absolute reaction rate constants for a total of nine HNMs. To elucidate the decomposition reaction …

Performance Of Constraint-Handling Techniques Applied To A Genetic Algorithm-Based Watershed Management Model, Kwisun Park Yu

Civil & Environmental Engineering Theses & Dissertations

Wet detention ponds are a commonly used structural best management practice to reduce nonpoint source pollutant loading into receiving water bodies. Design of these ponds is typically carried out individually to meet a target total suspended solids (TSS) removal level. An improvement to this approach is to generate cost-effective pond configurations that meet system-wide targets for removal of pollutant loadings, corresponding to a specific build-out land use plan. The cost-effectiveness can be further improved through appropriate land use allocation planning conducted simultaneously with the design of detention ponds. Harrell and Ranjithan (2003) presented an evolutionary algorithm- (EA-) based modeling approach …

Source Identification Of Ammonia Inputs To The Wastewater Treatment Holding Pond At International Paper Franklin Mill, Melissa Riddick Wolford

Civil & Environmental Engineering Theses & Dissertations

While nitrogen is an essential nutrient in aquatic systems, elevated levels of nitrogen can be fatal to many aquatic organisms including fish and other organisms that are in the river. Elevated levels of ammonia have been recently (2001-2002) detected in the water released from a wastewater treatment system holding pond at International Paper Franklin, Virginia and are a concern for the receiving system. The elevated ammonia concentrations observed in previous years were not observed in 2003, due likely to increased precipitation and the occurrence of a major hurricane (Hurricane Isabel) during the sampling period that may have influenced the observations. …

Extension Of A Cross-Shore Beach Profile Model For Coarse Materials And Steep Slopes, Kentaro Hayashi

Civil & Environmental Engineering Theses & Dissertations

In the present SBEACH model, the effective grain size can range from 0.13 to 1.0 mm. The grain size greatly influences three main processes of the model: fall velocity, sediment transport direction, and sediment transport rate. First, the theory of the fall velocity, which is called Hallermeier's formula in the SPM (1984), is replaced by the new theory in the CEM (2002). Second, the sediment transport direction is changed by two criteria. One was developed by Sunamura and Horikawa (1974). This theory includes the beach slope. The other was derived by Ahrens and Hands (2000). The effective grain size range …

Adaptive Parallel Framework Algorithm (Apfa) For Environmental Engineering Applications, Lianghua Zhou

Civil & Environmental Engineering Theses & Dissertations

This research proposes a new framework methodology for integrating environmental computer applications in flexible, open and adaptively and reusable manners so that the resulting application framework could be used to effectively, flexibly and rapidly handle various environmental problems and issues. Research also demonstrates the framework algorithm with a case study. The proposed algorithm is referred as Adaptive Parallel Framework Algorithm (APF A). Core concept of the APF A is based on a parallelism, "many-to-one" mode to communicate among environmental applications, and takes advantages of a loosely coupled technology that helps archiving the required flexibility, extensibility and usability of integrated systems. …

Characterization And Removal Of Tributyltin (Tbt) From Shipyard Washwasters Laboratory And Full-Scale Studies, Ram Prasad

Civil & Environmental Engineering Theses & Dissertations

Tributyltin has long been used as a biocide in many consumer products to prevent biological growth and fouling. One of the persistent uses of tributyltin is as an antifouling agent in marine paints where its use prevents biological growths on hulls and greatly improves the fuel efficiency of ships. Due to observed adverse effects (tributyltin is an endocrine disrupter) on non-target organisms like shellfish, oysters and snails, the use of tributyltin in marine paints has been banned in many nations and its point source discharge is now regulated through the Virginia Permit Discharge Elimination System (VPDES) program (first state to …

Mass Transfer Reactions And Decay Sinks For Disinfectants In Water Distribution Systems, Jeremy B. Jones

Civil & Environmental Engineering Theses & Dissertations

Treatment plants utilize chlorine and chloramine both as a primary disinfectant for water purification and a secondary disinfectant for distribution system protection. The treatment goal is that the disinfectant residual be present throughout the distribution system until it reaches the customer's tap. Maintaining a residual throughout the system is critical for providing pathogen-free water and protecting human health. Therefore, water utility authorities are very interested in how disinfectants such as chlorine and chloramine decay as they travel through a water distribution system.

Current mathematical models typically divide the decay into two distinct phases. There is (1) decay occurring in the …

Adsorption Of Inorganic And Organic Ligands Onto Aluminum Hydroxide And Its Effect In Water Treatment, Peter Pommerenk

Civil & Environmental Engineering Theses & Dissertations

The inorganic anions fluoride, sulfate, and orthophosphate are ubiquitous substances in aqueous environments. These chemicals are also applied in drinking water treatment processes where fluoridation, coagulation with sulfate-based metal salts, or the use of passivating corrosion inhibitors or sequestering agents is practiced. If these ions are present at elevated levels in raw waters or added in the treatment train at points other than directly before entering a finished water reservoir, they can exert a negative influence on the removal of particles and natural organic matter.

Although the water chemistry of these inorganic ions seems to be well understood, their potential …

Towards Quantification Of Active Sand Volume In The Nearshore Profile, Sukru Serkan Ozger

Civil & Environmental Engineering Theses & Dissertations

An active sand volume concept is introduced for the first time in this study. The significance of this new concept and its possible practical uses for Coastal Engineering are discussed. A theory is proposed towards quantification of the active sand volume across a beach profile and the circumstances under which it should be defined are determined.

Next, a 12-year nearshore bathymetric data set surveyed at the Field Research Facility of the Army Corps of Engineers at Duck, NC is used to determine the hypothetical quantity of active volume. Statistical analysis of elevations at digitized cross-shore distances is performed and a …

A Buffered Advection/Dispersion Lake Water Quality Transport Framework For Modeling Lake Gaston Pipeline Intake Water Withdrawal, Lloyd Ashton Gatling

Civil & Environmental Engineering Theses & Dissertations

Water quality response to reservoir water withdrawal is investigated in Pea Hill Arm of Lake Gaston, a non-tidal reservoir tributary, where the point of water withdrawal is in an upstream tributary and influences the direction of tributary flow causing longitudinal velocity null flow conditions to occur. The study also focuses on control of withdrawal rate and timing to optimize both quality of water remaining in the tributary and quantity of water that can be safely withdrawn.

Research was conducted assuming steady state conditions and later under spatial and temporal variability experienced in the reservoir with main lake pool elevation fluctuations …

Development Of Baseline Water Quality Stormwater Detention Pond Model For Chesapeake Bay Catchments, William J. Musico

Civil & Environmental Engineering Theses & Dissertations

A stormwater detention pond model, EEMD (Environmentally Economic Management Design), was developed using VisualBasic to facilitate the design of extended detention basins. A detention basin is a design such that a site's stormwater runoff would meet certain environmental impact requirements. To ensure these environmental requirements are meet the Commonwealth of Virginia subscribes to the procedures outlined by the Chesapeake Bay Local Assistance Department (CBLAD).

The purpose of the Chesapeake Bay Local Assistance Department (CBLAD) Calculation Procedures is to ensure that the development of constructed areas do not further exacerbate current problems of stormwater-induced eutrophication and downstream flooding. The methodology is …

Shoreline Change Modeling As A Tool In Coastal Environmental Management, Jorge Espinoza Amaguana

Civil & Environmental Engineering Theses & Dissertations

The one-line numerical model GENESIS has been calibrated to evaluate its performance as a tool in providing insights into the physical components to manage the coastal environment. To calibrate the model, physical environmental data, literature research, and computer modeling methodologies were utilized in addressing the objectives of this thesis. The model was applied at three beaches of the Virginia Beach City with different man-made structures by using the actual field wave data for wave year J 997. Waves are the main environmental component affecting the coastal system; however, additional environmental data and the best engineering decision were used as model …

A Two Dimensional Distributed Hydrological Model For Infiltrating Watersheds With Channel Networks, Donald Lee Currey

Civil & Environmental Engineering Theses & Dissertations

A numerical model named Old Dominion Watershed Simulation Model (ODWSM) is developed for simulating the rainfall/runoff process that occurs over watersheds. ODWSM's computational modules include the capability to simulate two-dimensional overland flow, spatially varied infiltration and depression storage, interception and channel flow for irregular and looped networks.

Overland flow computation is performed by writing the two-dimensional kinematic wave equations in an implicit finite difference form. Computational speed is gained by using an upwind differencing scheme and solving the equations in the direction of flow. This solution method allows for the calculation of infiltration and depression storage to include rainfall, current …

A Calibrated Shoreline Change Model For The Southeast Atlantic Ocean Coast Of Virginia, Prasert Vangsantitrakul

Civil & Environmental Engineering Theses & Dissertations

The idea that the long-term historic shoreline change at a given site is mainly caused by spatial gradients in the net longshore sediment transport is generally accepted. The position changes of the coastline can therefore be modeled by calculating the coastal erosion or accretion from the longshore sediment transport. This study used the GENESIS software program, one-line model, to simulate and calibrate the long-term shoreline change of the southeast coast of Virginia from 1925 to 1980. The study reach covers 45- km from Cape Henry to the Virginia-North Carolina border.

This study experienced the lack of certain important historic data …

Characterization Of Rainfall Runoff Quality From A Shipyard Drydock, Peter Pommerenk

Civil & Environmental Engineering Theses & Dissertations

Water quality and hydrological data were collected during seventeen rain events and additional data was obtained from laboratory experiments to characterize the quality of stormwater runoff from a drydock located on the Elizabeth River in Norfolk, Virginia.

The results indicated that the concentrations of dissolved constituents in drydock runoff increased with decreasing flow rate, while solids concentrations exhibited positive correlation to flow rate, suggesting that the mobilization of particulate matter is velocity driven. Approximating the runoff hydrograph due to a storm event using a simple model enabled derivation of the average time that rainwater resides on the drydock surface before …

Modeling A High-Efficiency Ozone Injection Contactor, L. Bernard Garrett Jr.

Civil & Environmental Engineering Theses & Dissertations

Significant research over the last several years has focused on applying modeling equations for estimating design parameters of ozone contactors. Much of this research has focused on fine bubble diffusers, which are the more widely used injection system for ozone contactors in the U.S. A recently developed design incorporates a new ozone injection system called a sidestream venturi injector (SVI) which is used with a co-current downflow column to achieve very high ozone mass transfer efficiencies. A pilot study conducted at the Harwood's Mill water treatment plant in Newport News, Virginia, from June to December 1993 demonstrated the high mass …

Long-Term Effects Of Seawalls On The Adjacent Nonwalled Beaches Of A Historically Receding Shoreline, Bryan Norton Jones

Civil & Environmental Engineering Theses & Dissertations

Great debate has arisen in recent years over the effects seawalls may or may not have on the erosion rate of a historically receding shoreline. A primary obstacle to the formation of definite conclusions about this subject is the lack of long-term physical data, which must be collected prior to and following seawall construction. This thesis presents the results of a study using 15 years of beach profile data to determine how seawalls influence the existing erosional trends of the beach at Sandbridge, Virginia.

Three analysis methods using three time scales (historic, seasonal, and storms) were used to answer three …

Organic Matter Characterization Of Virginia Rivers And Reservoirs, Susanne Margaret Lockhart

Civil & Environmental Engineering Theses & Dissertations

Research was conducted on characterizing the DOC characteristics and to discern whether spatial and temporal variations exist in these characteristics as impacted by seasonal, hydrologic or other factors. Data was cumulative of two studies: the State-Wide Survey in which water samples were taken in March and July 1995 from surface waters in four physiographic regions of Virginia and the James River Peninsula Survey concentrating on reservoirs and rivers on the James River Peninsula.

Results illustrate that the two largest fractions of DOC were the hydrophilic and hydrophobic acid fractions. An increase in DOC was observed between the mountains and the …

A Receiving Water Quality Model For Dissolved Metal Runoff From A Floating Drydock, Thomas O. Fenn

Civil & Environmental Engineering Theses & Dissertations

A methodology for modeling the water quality mixing zone of dissolved metal bearing storm water runoff is presented with specific application to floating drydocks in a tidal estuary. The method relies upon a solution of the mass balance equation as contained in the computer program, Water Quality Analysis Simulation Program (WASPS), an Environmental Protection Agency (EPA) model. Separate applications are presented for dissolved metal and solid settling to optimize the WASPS program capabilities.

WASPS provides the capability to evaluate the mass balance equation in a finite difference scheme applied over a large number of small volume segments. The program may …

The Influence Of Seawalls On Beach Responses To Storms, Seasonal Transitions And Long-Term Erosion, John Marshall Hazelton

Civil & Environmental Engineering Theses & Dissertations

It has been argued that seawalls have a detrimental effect on the adjacent beaches. These effects may only be noticeable over a period of years or may be short-term effects associated with storms or with seasonal transitions of the beach. Many theories on beach and seawall interaction have been speculative and have lacked actual field or laboratory evidence for their basis.

This study uses four years of monthly and post-storm beach profile data to examine what influences the seawalls at Sandbridge, Virginia have on the adjacent beaches. Long-term effects of the seawalls are analyzed using fourteen years of profile data. …

Landfill Leachate Production And Gas Generation Numerical Model, John Edward Riester Jr.

Civil & Environmental Engineering Theses & Dissertations

Numerous processes occur in landfills which lend themselves to modeling. Many of the processes are mutually interdependent. An unsteady numerical model is developed combining the major processes. The three-dimensional moisture transport equations and boundary conditions are solved using an implicit finite difference scheme. The boundaries are determined through a two-dimensional runoff model for the landfill surface and a one-dimensional leachate liner flow model at the bottom of the landfill. The runoff model accounts for evapotranspiration, runoff, infiltration, and leachate recirculation. Richard's equation is solved for saturated and unsaturated vertical flows and Darcy's Equation is solved for lateral flow between adjacent …

Statistical Variations In Beach Parameter Change Rates For Walled And Non-Walled Profiles At Sandbridge, Virginia, Douglas Allen Bellomo

Civil & Environmental Engineering Theses & Dissertations

The interaction of seawalls {bulkheads) and beaches is a highly controversial subject today. In many locations all over the United States, seawalls have been both praised and ridiculed. It is well documented that Sandbridge, Virginia is, and has been, experiencing shoreline recession. Many believe however, that the recent construction of the seawalls has worsened this existing situation.

Fortunately, historical maps, and beach profiles are available to help determine if this is truly the case. The following defines several visible beach parameters, and describes how these parameters were calculated from two different data sources. Several methods and statistical techniques are then …

Evaluating The Effects Of Alum With Polyelectrolyte Coagulant Aids In Treatment Of Low Turbidity Waters, Kenneth John Stockwell

Civil & Environmental Engineering Theses & Dissertations

Potable water sources usually require treatment for removal of suspended organic and inorganic particles. Conventional treatment processes incorporate chemical coagulants for removal of these suspended particles. Alum is a widely used coagulant that can provide adequate removals of turbidity. However, high alum dosages are required for treatment of low turbidity waters producing a voluminous sludge that is difficult to dewater.

Recent Federal regulations have limited disposal options for chemical sludges. This has prompted a reevaluation of coagulants and their dosages with the goal of reducing the amount of sludge produced and improving the sludge handling characteristics necessary for ultimate disposal. …

An Engineering Solution To Improve Water Quality In A Tidal Lagoon, Richard Warren Price

Civil & Environmental Engineering Theses & Dissertations

Rising demand for better water quality stimulated research and development of ways to improve the quality level in existing as well as proposed water systems. At present, most of the solutions focus on biological and chemical processes.

Many natural or man-made water bodies act as receivers for both point and non-point pollution sources. Employment of biological and chemical treatment has proved successful in many of these cases; however, in some cases a more natural physical solution of an engineering mode would be more desirable. A "flushing" technique using the tidal fluctuation as a driving force has been investigated and the …