Environmental Engineering Commons^™

Combining Multivariate Statistical And Numerical Modeling For Coastal Hazards Analysis, Victor Malagon Santos

Electronic Theses and Dissertations, 2020-2023

Increased population density along the world's coastlines is driven by the wide range of services provided by costal systems, such as transportation, fisheries, trade, and tourism. Despite offering fundamental services, coastal systems are exposed to a range of natural hazards such as riverine and/or coastal flooding, and erosion, thus robust risk analyses are needed to protect coastal ecosystems, infrastructure, and people dwelling in proximity to the shoreline. Numerical and multivariate statistical models have become crucial tools in coastal risk management to support robust risk analyses, and their combined use provides many benefits in the analysis of coastal hazards. This dissertation …

Investigating The Removal Of Total Trihalomethanes In Tray And Spray Aeration Processes At Two Central Florida Groundwater Treatment Facilities, Zachary Protas

Electronic Theses and Dissertations, 2020-2023

An investigation has been completed that assessed the efficiency of tray and spray aeration processes on the removal of regulated total trihalomethanes (TTHMs) at two publicly owned potable groundwater treatment facilities located in Polk County, Florida: the Providence and Van Fleet water treatment plants (WTPs). Finished water from each of these facilities was fed to a pilot-plant that could be operated as either a tray, spray, or combined configuration. A series of four pilot aerator configurations were tested at each WTP. Test 1 evaluated the tray aerator operated in a recirculated multiple-pass mode. It was shown that three passes across …

การเพิ่มประสิทธิภาพการจัดการพลาสติกรีไซเคิลโดยใช้ระบบ Gis กรณีศึกษา: ชุมชนในจังหวัดระยอง, ชยานนท์ เทียนธนานุรักษ์

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้มีวัตถุประสงค์เพื่อศึกษาการจัดการขยะบรรจุภัณฑ์พลาสติกระดับชุมชนในพื้นที่จังหวัดระยองและสร้างแบบจำลองการแลกเปลี่ยนข้อมูลการรับซื้อขายขยะพลาสติกโดยใช้ระบบสารสนเทศทางภูมิศาสตร์ (Geographic information system; GIS) เพื่อช่วยในการจัดการขยะพลาสติกอย่างมีประสิทธิภาพและหมุนเวียนกลับมาใช้ประโยชน์สูงสุดตามหลักเศรษฐกิจหมุนเวียน ด้วยวิธีการสำรวจและรวบรวมข้อมูลชนิด ปริมาณขยะพลาสติกและที่ตั้งร้านรับซื้อในพื้นที่กรณีศึกษา 3 แห่ง ได้แก่ เทศบาลนครระยอง หมู่4 เทศบาลทับมา และชุมชนบ้านเอื้ออาทรวังหว้า ผลการวิจัยพบว่าการจัดการขยะพลาสติกในชุมชนกรณีศึกษาทั้ง 3 แห่งยังขาดความเชื่อมโยงในการจัดการขยะพลาสติกของผู้มีส่วนได้เสียตลอดห่วงโซ่คุณค่า และยังไม่ทราบช่องทางติดต่อการซื้อขายหรือตำแหน่งที่ตั้งของร้านรับซื้อหรือโรงงาน ดังนั้นงานวิจัยนี้ช่วยให้ทราบถึงพิกัดร้านรับซื้อขยะพลาสติกประเภทต่าง ๆ ในชุมชนกรณีศึกษาโดยใช้ระบบ GIS และเสนอแบบจำลองการแลกเปลี่ยนข้อมูลการรับซื้อขายขยะพลาสติกในจังหวัดระยอง ซึ่งพบว่าปัจจุบันเส้นทางการขนส่งขยะพลาสติกของชุมชนกรณีศึกษาทั้ง 3 แห่ง ของเทศบาลนครระยอง ชุมชนหมู่4 เทศบาลทับมาและชุมชนบ้านเอื้ออาทรวังหว้าจากธนาคารขยะไปยังร้านรับซื้อขวด/ถุงพลาสติก และส่งต่อไปโรงงานรีไซเคิลมีระยะทางขนส่งเท่ากับ 430.55 , 286.91 และ 458.51 กิโลเมตร ตามลำดับ จึงนำเสนอทางเลือกการเปลี่ยนร้านรับซื้อขวด/ถุงพลาสติก และโรงงานรีไซเคิล พบว่าสามารถลดระยะทางขนส่งลงเท่ากับ 165.58, 149.65 และ 348.81 กิโลเมตร ตามลำดับ คิดเป็นร้อยละ 61.54, 47.84 และ 23.93 ตามลำดับ สามารถลดการปล่อยก๊าซเรือนกระจกลงร้อยละ 92.94 , 83.85 และ 77.35 ตามลำดับ ดังนั้นหากสามารถเปลี่ยนมาใช้เส้นทางการขนส่งที่เสนอแนะได้จะสามารถช่วยลดการใช้เชื้อเพลิงและการปล่อยก๊าซเรือนกระจกสู่ชั้นบรรยากาศได้

New York State Materials Recycling Facilities Report 2019, Firman Firmansyah, Yiyi Wang, Sameena Manzur, Sayidana Brannan-Douglas, Justin Lee, Andersson Lora, John O'Halloran, Elizabeth Hewitt, Krista L. Thyberg, David J. Tonjes

Technology & Society Faculty Publications

The composition of collected recyclables reported on here has some consistency across the three systems in terms of the general kinds of recyclables collected (but that is true for most US waste management systems). The grab samples analyzed here varied considerably in terms of overall composition. Clearly some of that has to do with the nature of the collection programs (single stream and dual stream, residential alone versus residential plus commercial) but it may also relate to the service areas for the systems, indicating that waste is highly context-driven and location-specific. Islip is an affluent suburban setting; Delaware County collects …

Mapping Michigan's Historic Coastlines, Ryan A. Williams

Dissertations, Master's Theses and Master's Reports

This five-year project, sponsored by the Michigan Department of Environment, Great Lakes, and Energy, is working to map how Michigan’s Great Lakes shorelines have changed over the past 80+ years. Products of this project include publicly available digital, georeferenced, historic aerial photography datasets, as well as map layers depicting the locations of historic shorelines and bluff lines from 1938, 1980, 2009, 2016, 2018, and 2020. Additional products include bluff retreat risk areas, shoreline rate of change map layers, and tools to assist in the development of future Coastal Vulnerability Index projects for the Great Lakes. All products are available as …

Water Quality Engineering And Wastewater Treatment, Yung-Tse Hung, Hamidi Abdul Aziz, Issam A. Al-Khatib, Rehab O. Abdel Rahman, Mario Gr Cora-Hernandez

Civil and Environmental Engineering Faculty Publications

No abstract provided.

Long Term Evaluation Of E. Coli Removal From Stormwater Using Recycled Steel Byproducts, Brenden Olevson

Electronic Theses and Dissertations

Stormwater runoff often carries a variety of pollutants and pathogens that can endanger public health and wildlife. One contaminant of concern often highlighted in stormwater quality is Escherichia Coli (E.Coli) because its presence indicates microbial contamination in water. Different types of media filtration are being studied to reduce contaminant concentrations in stormwater. In this study, steel byproducts were examined as a potential material to use in media filtration to remove E. Coli and other contaminants from stormwater. Batch scale studies were conducted in laboratory to evaluate the E. Coli removal potential of steel chips and steel slag over a 24-hour …

A Speciation Modeling Study Of Heavy Metal Adsorption To Plastic In Municipal Wastewater Treatment Plant Units, Kaitlyn Hague

Electronic Theses and Dissertations

Microplastics are an emerging concern due to their harmful effect to organisms and their ability to facilitate transport of contaminants including heavy metals. Microplastics can enter the environment through wastewater treatment plants, landfill leachate, and littering. Once in the environment microplastics can be distributed throughout rivers, the ocean, and lakes. In order to understand the adsorption of heavy metals to microplastics a geochemical modeling study was completed using Visual Minteq. Lab tests were completed to better understand what constituents are available in wastewater at four different locations: influent, clarifiers, digesters, and effluent. These constituents were then used to observe how …

Understanding The Weather- And Soil-Related Variability In Agricultural Water Footprints: Case Study Of Maize And Soybeans Grown In The St. Joseph Watershed, Karleigh M. Krieg

Dissertations, Master's Theses and Master's Reports

Introduced in 2002, the water footprint is a valuable tool for understanding the consumption of freshwater resources. The traditional approach to quantifying the water footprint is to sum the green, blue, and gray water footprint components. The green water footprint is the volume of water that comes from precipitation, is stored in the soil, and used by vegetation. The blue water footprint is the volume of surface or ground water that is withdrawn and applied to cultivated lands via irrigation. These components are based on the evapotranspiration of green and blue water resources, respectively. The gray water footprint is the …

การใช้ของเสียกระจกแผงพลังงานแสงอาทิตย์ทดแทนการใช้ปูนซีเมนต์บางส่วนในการผลิตมอร์ตาร์, ครองขวัญ ข่วงบุญ

Chulalongkorn University Theses and Dissertations (Chula ETD)

จากปริมาณของเสียแผงพลังงานแสงอาทิตย์ที่กำลังจะเกิดขึ้นภายในระยะเวลา 20-30 ปีจากการติดตั้งในช่วงพ.ศ. 2545-2558 อาจจะเป็นน้ำหนักได้ถึง 235,954 ตัน โดยส่วนใหญ่ประเทศไทยนิยมใช้แผงพลังงานแสงอาทิตย์ชนิดผลึกซิลิกอน ซึ่งแผงประเภทนี้มีปริมาณกระจกมากถึงร้อยละ 70-80 โดยน้ำหนักขององค์ประกอบแผง การจัดการของเสียแผงพลังงานแสงอาทิตย์ในประเทศไทยในขณะนี้มีการกำจัดด้วยการนำไปทิ้งที่หลุมฝังกลบอุตสาหกรรม ซึ่งเป็นการจัดการที่ไม่ยั่งยืนเพราะเป็นการสูญเสียทรัพยากรอย่างไร้ประโยชน์ ในงานวิจัยนี้มุ่งเน้นในการนำกระจกแผงพลังงานแสงอาทิตย์ชนิดผลึกซิลิกอนนำกลับมาใช้ประโยชน์ใหม่ โดยทำการศึกษาผลกระทบต่อสมบัติต่างๆของมอร์ตาร์ที่มีการแทนที่บางส่วนของปูนซีเมนต์ด้วยกระจกแผงพลังงานแสงอาทิตย์บดละเอียดขนาด d50 ที่ 4.97 ไมโครเมตร ที่ร้อยละ 0, 10, 20 และ 30 โดยน้ำหนัก จากผลการศึกษาพบว่าเมื่อเพิ่มปริมาณผงกระจกจะทำให้ ค่าการขยายตัวของซีเมนต์เพสต์มีค่าเพิ่มขึ้น ค่าการก่อตัวระยะต้นและระยะปลายของซีเมนต์เพสต์สั้นลง ค่าการไหลแผ่ของมอร์ตาร์มีค่าลดลง การซึมผ่านของคลอไรด์ในมอร์ตาร์ลดลง สำหรับกำลังรับแรงอัดมอร์ตาร์ช่วงอายุต้น พบว่ามอร์ตาร์ที่มีปูนซีเมนต์ที่มีการแทนที่ด้วยผงกระจกร้อยละ 0 ให้กำลังรับแรงอัดสูงที่สุด แต่ที่อายุ 90 วัน มอร์ตาร์ที่มีการแทนที่ปูนซีเมนต์ด้วยผงกระจกร้อยละ 10 ให้กำลังรับแรงอัดที่สูงที่สุด เนื่องจากการเกิดปฏิกิริยาปอซโซลานิกใช้เวลานานกว่าจะเกิดปฏิกิริยา

Revised Draft Final Butte Reclaimed Areas Maintenance And Monitoring (M&M) Plan In Accordance With Butte Reclamation Evaluation System (Bres), Pioneer Technical Services, Inc.

Silver Bow Creek/Butte Area Superfund Site

No abstract provided.

The Use Of Physically Based Models And Ensemble Forecasting For Storm Surge Risk Assessment In A Changing Climate, Jeane Camelo

Electronic Theses and Dissertations, 2020-2023

Storm surge has been the deadliest and costliest hurricane induced hazard in the coastal United States. In order to save property and lives, emergency managers must issue advisories guided by numerical models in a timely manner. However, these surge models are highly dependent on weather forecasts which contain uncertainties themselves as hurricanes traverse through the waters before making landfall. This dissertation aims to understand the contribution of uncertainties in hurricane properties, particularly the wind intensity which can contribute to uncertainties in storm surge models. Investigating these properties through numerical modeling is both computationally and time intensive. However by developing a …

Evolution Of Three Streambanks Before And After Stabilization And Record Flooding, Matthew Russell, Aaron R. Mittelstet, Tiffany Messer, Jesse T. Korus, R.M. Joeckel

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Stabilization projects are increasingly used to mitigate the effects of anthropogenic streambank erosion, yet the effectiveness of stabilization has been insufficiently measured. Sound monitoring practices inform adjustments in implementation and maintenance, which improve engineered effectiveness. Thus, the objectives of this study were to: 1) measure streambank migration from in three reaches stabilized with wooden jetties following a major flooding event, and 2) quantify deposition around the jetties between pre-flood and post-flood. Streambank deposition was measured in 2019 with a River Surveyor and Global Positioning System (GPS). Bank erosion rates in Reaches 1, 2 and 3 were 0.41, 0.96 and 0.07 …

Communities Of Nitrifying Microorganisms From Recirculating Aquaculture Systems (Rass) Under Different Ammonium Concentration And Salinity, Preeyaporn Pornkulwat

Chulalongkorn University Theses and Dissertations (Chula ETD)

Bioaugmentation of nitrifying cultures can accelerate nitrification during startup and transition periods of recirculating aquaculture systems (RASs) operations. To formulate nitrifying cultures for RASs, impacts of ammonia and salinity (NaCl) on culturing nitrifying microorganisms were comprehensively investigated by including currently known groups of nitrifying microorganisms (ammonia-oxidizing archaea (AOA), ammonia oxidizing bacteria (AOB), comammox, Nitrospira, and Nitrobacter). Initially, community structure of nitrifying microorganisms was observed in biofilters from water recirculation units of shrimp holding tanks operated at two different salinities of 2 and 15 g/L. Unique patterns of nitrifying communities consisting of AOA, comammox, and Nitrospira (without AOB and Nitrobacter) were …

Incinerator Ash Characterization - Implications For Elevated Temperature Landfills, Angel Villarruel-Moore

Electronic Theses and Dissertations, 2020-2023

The occurrence of temperatures in municipal solid waste (MSW) landfill gas (LFG) extraction systems in excess of 55°C is a problem that has gained much attention in the solid waste industry, both domestically and globally. Facilities which frequently experience such temperatures are termed Elevated Temperature Landfills (ETLFs), and recent research conducted at the University of Central Florida (UCF) has provided strong evidence that ash, both MSW incinerator ash (MSWIA) and coal combustion ash (CCA), when co-disposed with unburned MSW, provides materials which are able to participate in abiotic exothermic reactions that may lead to the development or sustainment of ETLFs. …

Treatment Of Cutting Oil Via Fe0/Air And Al0/Air Using Waste From Auto Parts Manufacturing, Warangkana Srimoke

Chulalongkorn University Theses and Dissertations (Chula ETD)

Used shot blast and aluminium dross wastes generated from auto part manufacturing were applied as catalysts under the modified-air Fenton (MAF) system to treat synthetic cutting oil wastewater. Experimental designs were applied to find optimum conditions in terms of size and amount of catalyst, initial pH, initial cutting oil concentration, air flow rate, and mixing speed. Fe0 and Al0 forms were found in used shot blast and aluminum dross, respectively, according to XRD and XRF results, and the element contents of Fe and Al were found to be 96.37 % and 37.13 %, respectively. For used shot blast under the …

Life Cycle Assessment Of Polylactic Acid Biopolymer Industrial Waste Management Techniques In Belize, Dennis J. Newby

Theses and Dissertations--Civil Engineering

In January 2020, the Government of Belize enacted an Implementation Strategy and Action Plan to phase-out single-use plastics and to transition to products like bioplastics. This work investigated the environmental effects of using alternative waste management techniques to manage polylactic acid biopolymer (PLA) waste by using life cycle assessment (LCA). The following treatment options were compared: landfill, landfill expansion, cogeneration, and anaerobic digestion. The landfill and landfill expansion processes both had a global warming potential of 0.01 kg of CO₂ eq. per kg of PLA waste managed compared to the cogeneration and anaerobic digestion processes -0.03 and -0.06 kg …

Quantifying The Source And Pathway Of Dissolved Reactive Phosphate In Karst Drainage Of The Inner-Bluegrass, Cory Radcliff

Theses and Dissertations--Biosystems and Agricultural Engineering

In the Midwestern U.S. seasonal hypoxia experienced in the Gulf of Mexico and harmful algal blooms in inland freshwater ponds, lakes, and rivers are partly fueled by dissolved orthophosphate loadings from disturbed landscapes. Efforts to reduce dissolved reactive phosphate (DRP) loadings have had varying levels of success and have led to insufficient water quality improvements. Inefficiencies in conservation strategies can stem from poor understanding of phosphate source and flow pathway dynamics. This study focused on monitoring sources and flow pathways of dissolved reactive P in a karst agroecosystem with phosphatic limestone. We collected event water samples at the Camden Creek …

Evaluating The Biotic Condition Of Restored Streams In Kentucky’S Inner Bluegrass Region, Charles Cole Crankshaw

Theses and Dissertations--Biosystems and Agricultural Engineering

Numerous stream restoration projects have been implemented in Kentucky’s Inner Bluegrass region to offset anthropogenic impacts. These projects range from full channel realignments to volunteer-led riparian installations. To assess the ability of said projects to restore stream habitat and biota, full restoration (n=12) and riparian (n=6) sites were compared to reference (n=6) and disturbed (n=12) sites using RBP and SVAP protocols, macroinvertebrate samples, and geomorphology. General trends for SVAP, RBP, and BI scores, starting with highest habitat or biotic quality, were reference sites, full and riparian restoration sites, then disturbed sites. The number of EPT taxa, another indicator of biological …

Predicting The Impacts Of Climate Change On The Great Lakes Water Levels Using A Fully Coupled 3d Regional Modeling System, Miraj Kayastha

Dissertations, Master's Theses and Master's Reports

The Great Lakes of North America are the largest surface freshwater system in the world and many ecosystems, industries, and coastal processes are sensitive to the changes in their water levels. The recent changes in the Great Lakes climate and water levels have particularly highlighted the importance of water level prediction. The water levels of the Great Lakes are primarily governed by the net basin supplies (NBS) of each lake which are the sum of over-lake precipitation and basin runoff minus lake evaporation. Recent studies have utilized Regional Climate Models (RCMs) with a fully coupled one-dimensional (1D) lake model to …

Peer-To-Peer Energy Trading For Networked Microgrids, Jonathan David Warner

Theses, Dissertations and Capstones

Considering the limitations of the existing centralized power infrastructure, research interests have been directed to decentralized smart power systems constructed as networks of interconnected microgrids. Therefore, it has become critical to develop secure and efficient energy trading mechanisms among networked microgrids for reliability and economic mutual benefits. Furthermore, integrating blockchain technologies into the energy sector has gained significant interest among researchers and industry professionals. Considering these trends, the work in this thesis focuses on developing Peer-to-Peer (P2P) energy trading models to facilitate transactions among microgrids in a multiagent network. Price negotiation mechanisms are proposed for both islanded and grid-connected microgrid …

Determination Of Pollutant Load Reductions To Three Mile Creek As A Result Of The Implementation Of Storm Water Bio-Infiltration Basins On The Usa Campus, Jordan E. Blackmon

Honors Theses

Three Mile Creek has been identified as an impaired urban stream and is now a priority for cleanup for both the City of Mobile and the Alabama Department of Environmental Management. Methods to better manage storm water runoff on the USA campus have begun, with a goal to reduce sediment and nutrient inputs to Three Mile Creek. Both sediment and nutrient inputs to Three Mile Creek disrupt habitat and lower dissolved oxygen concentrations, which are detrimental to overall stream health. Low Impact Development strategies are an innovative way to use nature-like, green-infrastructures to minimize storm water runoff quantity and improve …

Index-Based Approach With Remote Sensing For The Assessment Of Extreme Weather Impact On Watershed Vegetation Dynamics, Kushan Bellanthudawage

Electronic Theses and Dissertations, 2020-2023

Spatial technologies such as satellite remote sensing can be used to identify vegetation dynamics over space and time, which play a critical role in earth observations. Biophysical and biochemical features associated with vegetation cover can then be used to elucidate climate change impact such as floods and droughts on ecosystem that may in turn affect watershed-scale water resources management. Unlike single flood or drought event, intermittent extreme weather events may exert more physiological and biological pressures on the canopy vegetation. This study aims to investigate the climate change impacts on canopy vegetation, which occurred from March 2017 to October 2017 …

Effects Of Changes In Land Use Land Cover And Climate On Long-Term Total Dissolved Solids Trends In The Mid-Atlantic Region Of The United States, Melaine Edouard Kolimedje

Graduate Theses, Dissertations, and Problem Reports (ETD)

The Mid-Atlantic region (MAR) of the U.S. is subjected to a variety of stressors that affect the headwaters of the major rivers. Some of these stressors are abandoned mine drainage, agriculture, municipal point sources, urban areas, out-of-basin diversions, competing water uses, rapid population growths in the lowlands, alterations in water availability due to climate change and habitat alteration. In addition to these regional stressors, the rapid population growths and energy sources shifting have resulted in changes in land use and land cover (LULC) over the last few decades. The interactive effects of LULC and interannual/long-term climate changes have resulted in …

Reduction Of Energy Consumption Through Pump Efficiency Analysis, Riley Dodds

Williams Honors College, Honors Research Projects

Water scarcity, global warming, lack of fossil fuels, and future Green Act goals and legislature are at the forefront of policy change and election discussion within the United States. As civil engineers these topics are heavily discussed and challenged within the field and new solutions along with innovations are in constant demand. Within the community of Akron, the Akron Water Supply Water Plant continues to actively innovate and solve numerous concerns ranging from the quality of water to the overall operating costs. Energy consumption cost Akron Water Supply over $952,914.32 and 14,411,960 of kilowatts per hour of electrical energy to …

Laboratory Study Of The Effects Of Flexible Vegetation On Solute Diffusion In Unidirectional Flow, Sha Lou, Hao Wang, Hongzhe Liu, Guihui Zhong, Larisa Dorzhievna Radnaeva, Elena Nikitina, Gangfeng Ma, Shuguang Liu

Civil & Environmental Engineering Faculty Publications

Background

Flexible vegetation is an important part of the riverine ecosystem, which can reduce flow velocity, change turbulence structure, and affect the processes of solute transport. Compared with the flow with rigid vegetation, which has been reported in many previous studies, bending of flexible vegetation increases the complexity of the flow-vegetation-solute interactions. In this study, laboratory experiments are carried out to investigate the influence of flexible vegetation on solute transport, and methods for estimating the lateral and longitudinal diffusion coefficients in the rigid vegetated flow are examined for their applications to the flow with flexible vegetation.

Results

The experimental observations …

Evaluating Ozone And Granular Activated Carbon Treatment For Control Of Disinfection By-Product Formation For A Central Florida Groundwater Supply, Devon Higgins

Electronic Theses and Dissertations, 2020-2023

A pilot investigation that compared ozone oxidation with an integrated ozone and granular activated carbon (GAC) process for the control of regulated disinfection by-products at the University of Central Florida's water plant located at the Orlando campus has been completed. Treatment effectiveness was measured by monitoring the parameters pH, temperature, non-purgeable dissolved organic carbon (DOC), ultraviolet absorbance at a wavelength of 254 nm (UV254), specific ultraviolet absorbance (SUVA), excitation emission matrices (EEMs) and the associated formation of the DBP chemical groups total trihalomethanes (TTHMs) and haloacetic acids (HAAs). Groundwater that contained an average of 2.5 milligrams per liter (mg/L) DOC …

Assessing Different Plant-Centric Water Stress Metrics For Irrigation Efficacy Using Soil-Plant-Atmosphere-Continuum Simulation, Jingwen Zhang, Kaiyu Guan, Bin Peng, Ming Pan, Wang Zhou, Robert F. Grant, Trenton E. Franz, Daran Rudnick, Derek M. Heeren, Andrew Suyker, Yi Yang, Genghong Wu

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Understanding plant water stress (PWS) in the soil-plant-atmosphere-continuum (SPAC) that connects water supply from soil, water demand from atmosphere, and plant self-regulation is a prerequisite for efficient irrigation in response to water scarcity. Currently, PWS can be defined in various ways, for example, based on environmental factors and/or plant-centric metrics. The environment-based metrics usually do not take plants into consideration. Regarding the existing plant-centric metrics, their interconnections and abilities to capture the physical water constraints from both soil water supply and atmospheric water demand are still unclear. This research investigates the theoretical foundations behind different PWS metrics, and assesses their …

High-Temperature Performance Of Ambient-Cured Alkali- Activated Binder Concrete, Kruthi Kiran Ramagiri, Darshan Chauhan, Shashank Gupta, Arkamitra Kar, Dibyendu Adak, Abhijit Mukherjee

Civil and Environmental Engineering Faculty Publications and Presentations

Owing to their lower carbon footprint and efficient performance compared to portland cement (PC), alkali-activated binders (AAB) show promising potential as an alternative to PC. The present paper investigates the high-temperature performance of AAB concrete through compressive and bond strength tests. Four different AAB concrete mixes with varying proportions of fly ash: slag (100:0, 70:30, 60:40, and 50:50) cured under ambient conditions are exposed to elevated temperatures. The mechanical performance of AAB concrete is corroborated with microstructural changes. The results show that AAB concrete with fly ash: slag ratio of 70:30 exhibits the best mechanical performance after exposure to elevated …

Low-Level Groundwater Atrazine In High Atrazine Usage Nebraska Counties: Likely Effects Of Excessive Groundwater Abstraction, Moses New-Aaron, Olufemi Abimbola, Raheleh Mohammadi, Oluwaseun Famojuro, Zaeema Naveed, Azar Abadi, Jesse E. Bell, Shannon Bartelt-Hunt, Eleanor G. Rogan

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Recent studies observed a correlation between estrogen-related cancers and groundwater atrazine in eastern Nebraska counties. However, the mechanisms of human exposure to atrazine are unclear because low groundwater atrazine concentration was observed in counties with high cancer incidence despite having the highest atrazine usage. We studied groundwater atrazine fate in high atrazine usage Nebraska counties. Data were collected from Quality Assessed Agrichemical Contaminant Nebraska Groundwater, Parameter–Elevation Regressions on Independent Slopes Model (PRISM), and water use databases. Descriptive statistics and cluster analysis were performed. Domestic wells (59%) were the predominant well type. Groundwater atrazine was affected by well depth. Clusters consisting …