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Articles 4291 - 4320 of 6123
Full-Text Articles in Civil and Environmental Engineering
Environmental Consequences Of A Power Plant Shut-Down: A Three-Dimensional Water Quality Model Of Dublin Bay, Zeinab Bedri, Michael Bruen, Aodh Dowley, Barthelomew Masterson
Environmental Consequences Of A Power Plant Shut-Down: A Three-Dimensional Water Quality Model Of Dublin Bay, Zeinab Bedri, Michael Bruen, Aodh Dowley, Barthelomew Masterson
Articles
A hydro-environmental model is used to investigate the effect of cessation of thermal discharges from a power plant on the bathing water quality of Dublin Bay. Before closing down, cooling water from the plant was mixed with sewage effluent prior to its discharge, creating a warmer, less-saline buoyant pollutant plume that adversely affects the water quality of Dublin Bay. The model, calibrated to data from the period prior to the power-plant shut-down (Scenario 1), assessed the water quality following its shut-down under two scenarios; (i) Scenario 2: continued abstraction of water to dilute sewage effluents before discharge, and (ii) Scenario …
Bathing Water Quality Prediction Using An Integrated Catchment And 3-D Coastal Hydrodynamic Model, John O'Sullivan, Zeinab Bedri, Aisling Corkery, Louise Deering, Katalin Demeter, Wim Meijer, Barthelomew Masterson, Gregory O'Hare
Bathing Water Quality Prediction Using An Integrated Catchment And 3-D Coastal Hydrodynamic Model, John O'Sullivan, Zeinab Bedri, Aisling Corkery, Louise Deering, Katalin Demeter, Wim Meijer, Barthelomew Masterson, Gregory O'Hare
Conference papers
Under the new European Union Bathing Water Directive (2006/7/EC) which comes into force in 2014, more stringent bathing water quality standards, defined in terms of Escherichia coli (E.coli) and Intestinal Enterococci (I.E.), will apply in Irish bathing waters. Compliance with these standards is ensured through a structured water quality monitoring programme that is published by Authorities with responsibility for bathing water areas in advance of each bathing season. The directive recognises that elevated levels of faecal coliform bacteria in bathing areas can derive from the overland transport of waste from livestock in the rural fraction of river catchments. On days …
Gis-Based Flood Analysis For Adequate Flood Mitigation In An Unplanned Urban Area; The Case Of Pikine Dagoudane In Dakar County, Senegal, Sokhna Helene Diop
Gis-Based Flood Analysis For Adequate Flood Mitigation In An Unplanned Urban Area; The Case Of Pikine Dagoudane In Dakar County, Senegal, Sokhna Helene Diop
Masters Theses
Since 1989, Pikine Dagoudane, in the suburbs of Dakar City has faced several flooding events, resulting in economic loss, environmental degradation and severe disturbance of the social life of the residents. The mitigation programs implemented have not appeared to provide any relief since 2000. Review of the existing literature on the crisis has revealed that the general scale of the studies, and the insufficient attention to some of the major factors could be accounted for such little efficiency. This thesis applies a different approach, based on a small area and focusing mainly on topographic characteristics, to provide a better understanding …
Dairy Manure Flushwater Treatment By Packed-Bed Anaerobic Digesters, Neal Cary Adler
Dairy Manure Flushwater Treatment By Packed-Bed Anaerobic Digesters, Neal Cary Adler
Master's Theses
Wastewater treatment performance of three pilot-scale packed-bed anaerobic digesters with walnut shell medium was researched for treating dairy freestall barn flushwater. Reciprocation mixing was evaluated as a means to lessen channelization in the media bed and to improve biogas production and organic matter removal at ambient temperatures. Reciprocation has been used in biological nitrogen removal systems to introduce air into the system to repeatedly oxygenate nitrifying biofilm along with mixing (Behrends et al. 2003), but the anaerobic systems benefit from mixing. Two tanks were used in each system, where one was full and one was empty at any given time. …
Laboratory Evaluation Of A Turn Compensation Control System For A Ground Sprayer, Wesley M. Porter, Jorge A. Rascon, Yeyin Shi, Randal K. Taylor, Paul A. Weckler
Laboratory Evaluation Of A Turn Compensation Control System For A Ground Sprayer, Wesley M. Porter, Jorge A. Rascon, Yeyin Shi, Randal K. Taylor, Paul A. Weckler
Department of Agricultural and Biological Systems Engineering: Faculty Publications
The ability to compensate sprayer nozzle flow across a horizontal boom has the potential to mitigate the problem of inaccurate chemical application rate due to lateral speed differences when sprayers are turning. A laboratory testing platform and procedure were developed and tested with a commercial turn compensation control system for a ground sprayer. Virtual paths consisting of simulated GPS signals representing right and left turns separated by straight segments were simulated with four turning radii (75%, 125%, 250%, and 500%) based on boom width. Actual application rates from 11 nozzles spread across the boom were measured using load cells in …
Comparison Of Biofilm Media In Reciprocating Biofilters Treating Dairy Flushwater, Kyle Keoki Tatsuo Fooks
Comparison Of Biofilm Media In Reciprocating Biofilters Treating Dairy Flushwater, Kyle Keoki Tatsuo Fooks
Master's Theses
Reciprocating biofilters known as ReCip is a viable technology to manage nutrients, mainly nitrogen, problems at livestock operations such as swine farms and dairies. Past studies have demonstrated that ReCip is more adept at total nitrogen (TN) removal than traditional subsurface flow wetland systems. The traditional substrate used to attach biomass was rock aggregate; this media may be hard to obtain for some agricultural projects, so alternate substrates are tested and compared with the rock aggregate. The purpose of the study was twofold: first, different biofilm media were tested and compared in terms of treatment performance and, second, the long-term …
Settling Performance In Wastewater Fed High Rate Algae Ponds, Elliott Blake Ripley
Settling Performance In Wastewater Fed High Rate Algae Ponds, Elliott Blake Ripley
Master's Theses
Although high rate algae ponds (HRAPs) are a proven wastewater treatment technology with numerous environmental, social, and economic benefits, their widespread use has been hindered by inconsistent and unreliable settling performance. Hence, the goal of this thesis is to investigate how specific operational parameters affect the settling performance of HRAPs. Nine HRAPs (30 m2 surface area, 0.3 m depth) were operated as three triplicate sets, with each set run on either a 2, 3, or 4 day HRT continuously from January 25, 2012 through April 11, 2013. Settling performance was determined (i) by measuring the TSS of Imhoff cone …
The Fundamentals Of A Course On The Environmental Impacts Of Ships, Patricia A. Coker
The Fundamentals Of A Course On The Environmental Impacts Of Ships, Patricia A. Coker
LSU New Orleans Theses and Dissertations
No abstract provided.
Stormwater Harvesting Using Retention And In-Line Pipes For Treatment Consistent With The New Statewide Stormwater Rule, Martin Wanielista, Mike Hardin, Ikiensinma Gogo-Abite, Manoj Chopra
Stormwater Harvesting Using Retention And In-Line Pipes For Treatment Consistent With The New Statewide Stormwater Rule, Martin Wanielista, Mike Hardin, Ikiensinma Gogo-Abite, Manoj Chopra
BMP Trains Research and Publications
Stormwater rules and regulations are evolving. Thus, there is a need for research that supports alternative methods for water quality treatment of runoff water. The information in this report supports the use of filtration media called Biosorption Activated Media (BAM) that improves runoff water quality. Runoff to impaired waters may need additional treatment or reduced volume of discharge to meet a mass discharge limitation. In addition, some nutrients in runoff waters may need to be removed before they percolate to nutrient sensitive areas such as aquifers with discharge to springs or estuaries. Thus, stormwater harvesting or reuse is another best …
Preliminary Analysis Of Ghg Production From The Lincoln Water System To Determine Operating Energy And Infrastructure Construction Impacts, Martin Gakuria
Preliminary Analysis Of Ghg Production From The Lincoln Water System To Determine Operating Energy And Infrastructure Construction Impacts, Martin Gakuria
Department of Environmental Engineering: Theses and Other Student Research
The Lincoln Water System (LWS) provides water to the citizens, industries, and commercial areas within and near the City of Lincoln, Nebraska. The intent of this thesis is to determine if reductions in future per capita water demand will help reduce the building of infrastructure and reduce future pumping costs and uses the computation of greenhouse gasses to compare the effects of different degrees of water conservation.
Data analysis was performed on water production statistics and data (1994-2011) collected and provided by the City of Lincoln, Nebraska. Projections in accordance with the Lincoln-Lancaster County 2040 Comprehensive Plan were made to …
Full Depth Reclamation: Bringing Developing Countries' Transportation Up To Speed, Sadie Smith
Full Depth Reclamation: Bringing Developing Countries' Transportation Up To Speed, Sadie Smith
Civil Engineering Undergraduate Honors Theses
Often, a direct correlation is observed between a country’s transportation network and economic development. Evidence of this is observed all over the world. Full Depth Reclamation (FDR) is a roadway recycling technique that mills and mixes the existing roadway with a stabilizing agent and then re-compacts the mixture to create a thicker, stabilized pavement layer. This method is both cost effective and environmentally friendly, making it a very appealing option as the need to rehabilitate or increase the structural capacity of existing roads grows. In this study, the material characterization of FDR was examined as a composite material of both …
Aerosol Delivery As A Method For Enhancing Remedial Application In Contaminated Vadose Zones, Richard Hall
Aerosol Delivery As A Method For Enhancing Remedial Application In Contaminated Vadose Zones, Richard Hall
All Dissertations
Remediation of contaminated vadose zones is often hindered by an inability to effectively distribute liquid- or solid-phase amendments. Many amendment-based approaches, such as bioremediation, chemical oxidation, and reactive barriers have been successful in saturated formations. However, these remedial approaches have seen limited application in unsaturated materials, largely because of difficulties delivering amendments.
Aerosol delivery is a promising approach for distributing amendments in contaminated vadose zones. The amendments are aerosolized, creating a cloud of micron to sub-micron-scale liquid droplets held suspended in a gas by Brownian motion. During injection into porous media, the aerosol particles are transported along with the gas …
Stormwater Pollution Treatment Bmp Discharge Structures, Miles F. Simmons
Stormwater Pollution Treatment Bmp Discharge Structures, Miles F. Simmons
Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research
Structural best management practices (BMPs) are used to capture and treat stormwater runoff. Most structural BMPs provide treatment by filtering runoff through a filter media or collecting it in a detention basin and slowly discharging it over an extended period of time to allow suspended solids and associated contaminants to settle out. The purpose of this study is to design an effective outlet structure that provides adequate filtration or slows discharge to 40 hours.
A model detention basin was constructed in the Civil Engineering Hydraulics Laboratory at the University of Nebraska-Lincoln (UNL) and two full scale outlet structures were tested …
Influence Of Pcb-Contaminated Water Bodies On The Pcb Content Of Riparian Vegetation Through Foliar Deposition, Timothy Matthew Sattler
Influence Of Pcb-Contaminated Water Bodies On The Pcb Content Of Riparian Vegetation Through Foliar Deposition, Timothy Matthew Sattler
All Theses
Polychlorinated biphenyls (PCBs) are a class of persistent organic pollutants that are generally considered semi-volatile. Volatilization and transport of PCBs from contaminated water bodies can result in PCB accumulation on terrestrial plant surfaces, acting as an entry point for contaminants into terrestrial food webs. Evergreen plants can serve as biomonitors of this PCB accumulation, as they often retain foliage for several years, allowing for greater concentrations to accumulate and subsequently be measured. Rhododendron maximum plants often grow in the riparian zone adjacent to water bodies in the Appalachian region, such as near Town Creek, Pickens, South Carolina. This research aimed …
Effect Of Deposition From Static Test Fires On Corn And Alfalfa, Scout Mendenhall
Effect Of Deposition From Static Test Fires On Corn And Alfalfa, Scout Mendenhall
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Alliant Techsystems, Inc (ATK) manufactures solid rocket motors for the National Aeronautics and Space Administration (NASA) at the Promontory, UT facility. Periodically ATK conducts static test fires, where the rocket is restrained horizontally and fired into a hillside. The plume entrains native soil and is carried by the wind until it cools and settles. Although the area around ATK is sparsely populated, residents of nearby Penrose and Thatcher, UT are concerned with the deposition of the test fire soil (TFS) from the static rocket tests. In 2010, several crop fields nearing harvest were dusted with TFS, prompting the investigation of …
Using Qual2kw As A Decision Support Tool: Considerations For Data Collection, Calibration, And Numeric Nutrient Criteria, Andrew J. Hobson
Using Qual2kw As A Decision Support Tool: Considerations For Data Collection, Calibration, And Numeric Nutrient Criteria, Andrew J. Hobson
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Surface water quality in the United States is managed by the U.S. Environmental Protection Agency (EPA) under direction of the Clean Water Act. Designated uses are required for all state waters. Numeric or narrative water quality standards provide measures to determine if each waterbody meets the intended use. Narrative standards typically include vague terminology that is difficult to interpret and this has led EPA to encourage states to develop numeric criteria for nutrients in all its streams, rivers, and lakes. These numeric nutrient criteria are intended to stave off the harmful effects of over-growth of aquatic plants which can result …
Investigating The Feasibility Of Growing Algae For Fuel In Southern Nevada, Faegheh Moazeni
Investigating The Feasibility Of Growing Algae For Fuel In Southern Nevada, Faegheh Moazeni
UNLV Theses, Dissertations, Professional Papers, and Capstones
Microalgae capable of growing in waste are adequate to be mass-cultivated for biodiesel, avoiding fertilizers and clean water, two obstacles to sustainability of the feedstock production. This study replaces fertilizers and clean water with waste products. The investigated wastes include (1) the liquid fraction of sewage after solids and particles are removed, known as centrate, and (2) algal biomass residue, i.e. the algae remaining at the end of the lipids extraction process at biofuel plants. These wastes contain sufficient amount of nitrogen and phosphorus required for algal growth. This study proposes a system in which centrate would be used as …
Soil Organic Carbon Dynamics In Agriculture: Model Development And Application From Daily To Decadal Timescales, Matthew P. Pelton
Soil Organic Carbon Dynamics In Agriculture: Model Development And Application From Daily To Decadal Timescales, Matthew P. Pelton
Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research
Soil carbon (C) is the largest terrestrial C pool globally, containing more C than the atmosphere and biosphere. Soil organic carbon (SOC) is a source and sink of CO2 emissions to and from the atmosphere, thus influencing future climate change. Understanding SOC dynamics is also important for maintaining C stocks to sustain and improve crop yields. An existing model to estimate changes in SOC due to respiration was modified to operate in three computational platforms: MS Excel, MS Excel with Visual Basic for Applications, and supercomputing. This model was validated against CO2 flux data from a 9-year field …
Predicting Groundwater Trading Participation In The Upper Republican River Natural Resource District, Elizabeth M. Juchems
Predicting Groundwater Trading Participation In The Upper Republican River Natural Resource District, Elizabeth M. Juchems
Department of Agricultural Economics: Dissertations, Theses, and Student Research
The goal of this thesis is to predict participation in groundwater trading and the directions of trades among participants. Specifically, the paper considers both formal and informal trading of groundwater used for crop irrigation purposes and attempts to identify those characteristics that predict the probability of trade participation and whether an individual is a buyer or seller of groundwater rights. While the public benefits from efficient use of groundwater include adequate stream flow in hydrologically connected areas and future use of groundwater supplies, there are significant private benefits to landowners especially in water-short areas. Groundwater trading can help move water …
Sustainable Urban Rail Trails: Designing The Cross Kirkland Corridor, Mia Cooledge
Sustainable Urban Rail Trails: Designing The Cross Kirkland Corridor, Mia Cooledge
Scripps Senior Theses
This thesis is a guide to building a sustainable rail-trail, wherein I focus on invasive species removal, green pavement, and creating an inviting space with the inclusion of integrated art. When the City of Kirkland, WA purchased the 5.75 mile long section of railroad going through the city, I approached city manager Kurt Triplett to ask about his plans for the corridor. He liked the idea of aiming for a sustainable trail, so I wrote a guide to building an environmentally friendly trail based on a number of prominent readings on sustainable design.
Floatovoltaics: Quantifying The Benefits Of A Hydro-Solar Power Fusion, Abe Mckay
Floatovoltaics: Quantifying The Benefits Of A Hydro-Solar Power Fusion, Abe Mckay
Pomona Senior Theses
To slow climate change, humans should take immediate and widespread action. One way to slow climate change is by switching to switch to renewable power plants such as solar fields. Recently, pioneering companies have built solar fields on water bodies. This study found that such a pairing of water and solar could increase production efficiency by 8-10% through panel cooling, save millions of liters of water from evaporation, and produce energy with under-utilized space.
Assessment Of Solar Photovoltaic Technologies Using Multiple Perspectives And Hierarchical Decision Modeling, Nasir Jamil Sheikh
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 …
Runoff Of Silvicultural Herbicides Applied Using Best Management Practices, Matthew W. Mcbroom, Jeff Louch, R Scott Beasley, Mingteh Chang, George G. Ice
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 …
Sensitivity Analysis Of A Proposed Model For Removal Efficiency Of Trihalomethanes (Thms) Using Spray Aeration, Aidan Cecchetti
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 …
Building Upon Common-Pool Resource Theory To Explore Success In Transitioning Water Management Institutions, Christina M. Hoffman
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 …
Evaluating Alternatives For Augmented Water Quality Improvement Utilizing Oyster Restoration As Best Management Practice (Bmp), Stephanie Roberts Long
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
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
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 …
Fate Of Malathion In An Activated Sludge Municipal Wastewater Treatment System, Edward B. Walters
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.
Influence Of Media Size And Flow Rate On The Transport Of Silver Nanoparticles In Saturated Porous Media: Laboratory Experiments And Modeling, Travis J. Meidinger
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 …