Environmental Engineering Commons^™

Application Of Mixed Iron Oxides In Subsurface Remediation Technologies, Saidur Rahman Chowdhury

Electronic Thesis and Dissertation Repository

Heavy metal contamination of soil and groundwater has been a concern in water supply and public health in many countries where the water supply system draws primarily from groundwater. In the present study, mixed maghemite-magnetite nanoparticles have been used as adsorbents for Cr(VI), As and Cd(II) removal. From the study, it is apparent that the removal of Cr(VI ), Cd(II) and As(V) by mixed iron oxide nanoparticles depends on pH, temperature, contact time, solid/liquid ratio and initial concentration of heavy metals. The results showed that Cr(VI) adsorption on mixed maghemite-magnetite was dependent on solution pH between 3 and 6. Theoretical …

Effect Of Groundwater-Lake Interactions On The Distribution Of Arsenic In A Freshwater Beach, Jacky Sk Lee

Electronic Thesis and Dissertation Repository

This thesis presents field measurements and numerical modeling that provide insight into the nearshore geochemical conditions and groundwater flows controlling the mobility of arsenic (As) in a freshwater beach aquifer and its potential discharge to Lake Erie. Field measurements were performed via shore-normal monitoring transects installed at beaches (Little Beach and Main Beach) located adjacent to a brownfield industrial harbour site that has elevated sediment and groundwater As concentrations. Detailed pore water chemistry analyses revealed elevated As (up to 0.056 mg/L) 1 - 2 m below the shoreline at all transect locations. The distributions of species in the aqueous and …

Biofilm Control In A Fludized Bed Bioreactor (Fbbr) Treating Municipal Wastewater: Optimization, Modeling, And Nitrous Oxide (N2o) Emissions, Ahmed Eldyasti

Electronic Thesis and Dissertation Repository

Among the various biological wastewater treatment processes for industrial and municipal wastewater treatment, fluidized bed bioreactors (FBBR) demonstrate numerous advantages compared to suspended growth systems such as lower hydraulic retention time, high surface area and accordingly high biomass retention time, higher volumetric conversion rates, lower sensitivity to temperature, and less sludge production. Despite the numerous biofilm bioreactor configurations and system schemes that are currently available for a wide variety of environmental applications, the development and optimization of a stable biofilm that is capable of offering effective and integrated functions, i.e. biodegradation, biomass-liquid separation, and biomass retention along with a substantial …

Assessment Of Solar Photovoltaic Technologies Using Multiple Perspectives And Hierarchical Decision Modeling, Nasir Jamil Sheikh

Dissertations and Theses

The objective of this research is to build a decision model for a comprehensive assessment of solar photovoltaic technologies using multiple perspectives. These perspectives include: social, technological, economic, environmental, and political (STEEP) with each perspective consisting of multiple criteria. Hierarchical decision modeling and expert judgment quantification are used to provide the relative ranking of the perspectives and criteria. Such modeling is effective in addressing technology evaluations with competing and contrasting perspectives and criteria where both quantitative and qualitative measurements are represented. The model is then operationalized by constructing desirability functions for each criterion. The combined results provide an overall numerical …

Building Upon Common-Pool Resource Theory To Explore Success In Transitioning Water Management Institutions, Christina M. Hoffman

School of Natural Resources: Dissertations, Theses, and Student Research

Nebraska, like many regions around the world, is faced with the challenge of adapting to a new era in water management. Increasing demands for water resources, mounting concerns over threatened and endangered species, and obligations to abide by interstate water allocation agreements have motivated Nebraska to revisit traditional water management approaches. However, although Nebraska’s water management institutions have undergone much change, little research exists on the influence these changes have had on the ability of water institutions to successfully manage water allocations. This research (1) qualitatively explores the perspectives and experiences of stakeholders in the overappropriated region of the Platte …

Sensitivity Analysis Of A Proposed Model For Removal Efficiency Of Trihalomethanes (Thms) Using Spray Aeration, Aidan Cecchetti

Honors Theses and Capstones

Trihalomethanes (THMs) form in drinking water treatment systems as a byproduct of chlorination and are problematic from a public health perspective due to their carcinogenic potential and their potential for additional formation throughout distribution systems. Recently, regulations have tightened on THMs in an attempt to reduce the risk of exposure for consumers at the far ends of distribution systems. Due to widespread use of chlorine and the reluctance of drinking water providers to overhaul current treatment systems, research has been undertaken to investigate post-treatment removal of THMs. One such method is spray aeration, whereby water is recycled in water storage …

Runoff Of Silvicultural Herbicides Applied Using Best Management Practices, Matthew W. Mcbroom, Jeff Louch, R Scott Beasley, Mingteh Chang, George G. Ice

Faculty Publications

Nine small (2.2 to 2.9 ha) and four large (70 to 135 ha) watersheds in East Texas, USA, were instrumented to compare herbicide runoff under different silvicultural systems with best management practices (BMPs). Two treatments were evaluated: conventional, with clearcutting, aerial herbicide site preparation, and hand-applied banded herbaceous release; and intensive, in which subsoiling, aerial fertilization, and a second-year aerial herbicide application were added. Herbicides were applied as operational tank mixes. The highest imazapyr concentration found in stream water was 39 mg L^‑1 during the first storm after application (23 days after treatment, DAT) and in-stream concentrations …

Evaluating Alternatives For Augmented Water Quality Improvement Utilizing Oyster Restoration As Best Management Practice (Bmp), Stephanie Roberts Long

Civil & Environmental Engineering Theses & Dissertations

Due to several anthropogenic influences, the Chesapeake Bay has experienced a marked decrease in water quality since the colonists arrived at the Jamestown settlement in Virginia during the 1600s. Higher concentrations of nitrogen and phosphorus have enriched the estuaries and coastal waters via point sources (sewage treatment plants and industrial wastes), nonpoint sources (agricultural run-off and septic tank discharges) and the atmosphere (Newell et al., 2005). Restoring oyster beds is considered a Best Management Practice (BMP) to improve water quality as well as provide physical habitat for aquatic species and a healthier estuarine system (USACE Native Oyster Restoration Master …

Development Of Peptide Nanotube-Modified Biosensors For Gas-Phase Organophosphate Detection, Peter A . Baker

Theses and Dissertations

Vapor-phase detection of the model organophosphate malathion was achieved using enzymes encapsulated in peptide nanotubes and attached to gold screen-printed electrodes. Malathion was chosen as the model for this experiment because its binding mechanism with acetylcholinesterase (AChE) is identical to its more potent counterparts (such as sarin or VX), but it has an extremely low human toxicity, which makes it both practical and easy to use. The peptide nanotubes had horseradish peroxidase encapsulated inside and were coated with both acetylthiocholine (ASCh) and AChE on the outside. ASCh hydrolysis, which produces thiocholine, was catalyzed by the AChE. The thiocholine was then …

Biodegradation Of An Organophosphate Chemical Warfare Agent Simulant By Activated Sludge With Varying Solid Retention Times, Allen K. Janeczko

Theses and Dissertations

This study examined the fate of malathion, a surrogate compound for VX studies, in bench-scale sequencing batch bioreactors being operated under varied solid retention times (SRTs) to simulate the activated sludge process in wastewater treatment facilities. Results show that a constant influent of the malathion will largely be removed. However, the heterotrophic bacteria undergo a stress response which temporarily inhibits malathion removal, the extent of which increases with increasing SRTs. After this stress response takes place, the activated sludge is able to resume a high degree of malathion removal, even with increased influent concentration; however, this is done so at …

Influence Of Media Size And Flow Rate On The Transport Of Silver Nanoparticles In Saturated Porous Media: Laboratory Experiments And Modeling, Travis J. Meidinger

Theses and Dissertations

Silver nanoparticles (AgNPs) are widely produced and used. Because of their potential toxicity and the possibility of their release into the environment, it is important to understand the factors involved in their transport; particularly how they may move in groundwater, which is a potential pathway to human and environmental receptors. By passing a solution of 15 mg/L AgNPs with an average size of 17 nm through sand-filled glass columns, this study looks at the physical effects of flow rate and media size on transport. Three different sand sizes ( 0.074, 0.21-0.297, and 0.4-2.0mm) were used, as well as two different …

Fate Of Malathion In An Activated Sludge Municipal Wastewater Treatment System, Edward B. Walters

Theses and Dissertations

Organophosphate compounds are used as pesticides and in chemical warfare agents such as nerve agents. VX (O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate) is one of the most toxic and environmentally persistent of these nerve agents. This research examined the fate of malathion, a pesticide and surrogate of VX (O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate), in bench-scale activated sludge (AS) sequencing batch reactors. Sorption kinetics and sorption equilibrium isotherm experiments indicate that sorption to AS biomass was not a statistically important removal mechanism. However, approximately 90% of the initial 4.25 mg L-1 malathion concentration degraded primarily via heterotrophic activity.

Design Of An Underwater Video And Gps Mapping System For The Exploration Of Streambed Aquatic Populations, William Barbour

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

This design project was initiated due to the need for an underwater video mapping system optimized for exploration along the streambed or riverbed and under rocks. Such a system would be used for population mapping of fish and other aquatic species. The system also needed to incorporate global positioning system data with the visual data. The current prototype successfully fulfills the requirements for underwater practicality and visual and GPS data collection. It incorporates a compact waterproof camera with Sony lens, two Fenix high-intensity waterproof flashlights for illumination, a handheld DVR for recording video, and a Garmin 60CSx GPS unit. The …

A Multi-Objective Facility Location Model For Closed-Loop Supply Chain Network Under Uncertain Demand And Return, Saman Hassanzadeh Amin, Guoqing Zhang

Mechanical, Automotive & Materials Engineering Publications

A closed-loop supply chain (CLSC) network consists of both forward and reverse supply chains. In this paper, a CLSC network is investigated which includes multiple plants, collection centres, demand markets, and products. To this aim, a mixed-integer linear programming model is proposed that minimizes the total cost. Besides, two test problems are examined. The model is extended to consider environmental factors by weighed sums and ε-constraint methods. In addition, we investigate the impact of demand and return uncertainties on the network configuration by stochastic programming (scenario-based). Computational results show that the model can handle demand and return uncertainties, simultaneously.

Effects Of Nitrogen Deposition And Empirical Nitrogen Critical Loads For Ecoregions Of The United States, Linda Pardo, Mike Fenn, Christine Goodale, Linda. Geiser, Charles Driscoll, Edith Allen, Jill Baron, Roland Bobbink, Williams Bowman, Christopher Clark, Bridget Emmett, Frank Gilliam, Tara Greaver, Sharon Hall, Erik Lilleskov, Lingli Liu, Jason Lynch, Knute Nadelhoffer, Steven Perakis, Molly Robin-Abbott, John Stoddard, Kathleen Weathers, Robin Dennis

Frank S. Gilliam

Human activity in the last century has led to a significant increase in nitrogen (N) emissions and atmospheric deposition. This N deposition has reached a level that has caused or is likely to cause alterations to the structure and function of many ecosystems across the United States. One approach for quantifying the deposition of pollution that would be harmful to ecosystems is the determination of critical loads. A critical load is defined as the input of a pollutant below which no detrimental ecological effects occur over the long-term according to present knowledge.

The objectives of this project were to synthesize …

Soil Chemistry Response To Wollastonite (Casio3) Addition At Hubbard Brook, Chris E. Johnson

Chris E Johnson

No abstract provided.

Soil Chemistry Response To Wollastonite (Casio3) Addition At Hubbard Brook, Chris E. Johnson

Civil and Environmental Engineering

No abstract provided.

The Effects Of Physical Activity On Greenhouse Gas Emissions For Common Transport Modes In European Countries, Aidan Duffy, Robert Crawford

Articles

This paper applies a life cycle methodology to estimate activity-related contributions of transport modes to GHG emissions. The methodology uses national input-output tables, environmental accounts, household budget data and nutritional data to derive food-sector GHG coefficients of consumption for ten European countries. The food energy requirements for each mode of transport are estimated taking account of the modal activity level and energy requirements. Walking, cycling, driving and bus travel are considered. Typical national food energy-related emissions for walking, cycling, and driving ranged from 25.6 - 77.3 gCO2-eq/pass.km, 10.4 - 31.4 gCO2-eq/pass.km and 1.7 - 5.2 gCO2-eq/pass.km; passenger transport was found …

Predicting Landslides In Real Time, Michael J. Olsen

TREC Project Briefs

The Oregon Department of Transportation, or ODOT, has an ongoing struggle to maintain public highways against earth movements such as erosion, earthquakes and landslides. An earthquake or landslide can close down a road for days, while highway workers fight to keep supply lines open and repair the damage. Particularly along Oregon’s coastal roads with high sea cliffs, these natural processes are a constant threat to transportation infrastructure. The damage caused by gradual erosion is typically not detectable until there is a landslide or other disaster, costing the state considerable time and money to repair. New technology has the potential to …

Design Of A Transpired Air Heating Solar Collector With An Inverted Perforated Absorber And Asymmetric Compound Parabolic Concentrator., Nasif Shams

Doctoral

absorber and an asymmetric compound parabolic concentrator was applied to increase the intensity of solar radiation incident on the perforated absorber. A 2D ray tracing model quantified optical efficiency at different incident angles within 27o to 89o incident angles. The beam efficiency was found to vary between 72% and 79% and diffuse efficiency was found to vary between 48.2% and 65%. The average thermal efficiency was found to be approximately 55%-65% with average radiation above 400 W/m2 for flow rates in the range of 0.03 kg/s/m2 to 0.09 kg/s/m2. Experimental results at air flow rates of 0.03 kg/s/m2 and 0.09 …