Environmental Engineering Commons^™

Prediction Of Neighbor-Dependent Microbial Interactions From Limited Population Data, Joon-Yong Lee, Shin Haruta, Souichiro Kato, Hans C. Bernstein, Stephen R. Lindemann, Dong-Yup Lee, Jim K. Fredrickson, Hyun-Seob Song

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Modulation of interspecies interactions by the presence of neighbor species is a key ecological factor that governs dynamics and function of microbial communities, yet the development of theoretical frameworks explicit for understanding context-dependent interactions are still nascent. In a recent study, we proposed a novel rule-based inference method termed the Minimal Interspecies Interaction Adjustment (MIIA) that predicts the reorganization of interaction networks in response to the addition of new species such that the modulation in interaction coefficients caused by additional members is minimal. While the theoretical basis of MIIA was established through the previous work by assuming the full availability …

Geostatistical Features Of Streambed Vertical Hydraulic Conductivities In Frenchman Creek Watershed In Western Nebraska, Olufemi P. Abimbola, Aaron R. Mittelstet, Troy E. Gilmore

Department of Agricultural and Biological Systems Engineering: Faculty Publications

This study evaluated the spatial variability of streambed vertical hydraulic conductivity (K_v) in different stream morphologies in the Frenchman Creek Watershed, Western Nebraska, using different variogram models. Streambed K_v values were determined in situ using permeameter tests at 10 sites in Frenchman, Stinking Water and Spring Creeks during the dry season at baseflow conditions. Measurements were taken both in straight and meandering stream channels during a 5 day period at similar flow conditions. Each test site comprised of at least three transects and each transect comprised of at least three K_v measurements. Linear, Gaussian, exponential …

Ultrasmall Mixed Eu−Gd Oxide Nanoparticles For Multimodal Fluorescence And Magnetic Resonance Imaging Of Passive Accumulation And Retention In Tbi, Badrul Alam Bony, Hunter A. Miller, Aria W. Tarudji, Connor C. Gee, Anandakumar Sarella, Michael G. Nichols, Forrest Kievit

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. TBI can have a long-term impact on the quality of life for survivors of all ages. However, there remains no approved treatment that improves outcomes following TBI, which is partially due to poor delivery of therapies into the brain. Therefore, there is a significant unmet need to develop more effective delivery strategies that increase the accumulation and retention of potentially efficacious treatments in the injured brain. Recent work has revealed that nanoparticles (NPs) may offer a promising approach for site-specific delivery; however, a detailed understanding of the …

Predicting Total Petroleum Hydrocarbons In Field Soils With Vis–Nir Models Developed On Laboratory-Constructed Samples, Nuwan Wijewardane, Post Doc Research Associate, Yufeng Ge, Natasha Sihota, Thomas Hoelen, Toni Miao, David C. Weindorf

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Accurate quantification of petroleum hydrocarbons (PHCs) is required for opti- mizing remedial efforts at oil spill sites. While evaluating total petroleum hydro- carbons (TPH) in soils is often conducted using costly and time-consuming lab- oratory methods, visible and near-infrared reflectance spectroscopy (Vis–NIR) has been proven to be a rapid and cost-effective field-based method for soil TPH quantification. This study investigated whether Vis–NIR models calibrated from laboratory-constructed PHC soil samples could be used to accurately estimate TPH concentration of field samples. To evaluate this, a laboratory sample set was constructed by mixing crude oil with uncontaminated soil samples, and two field …

Interrelationships Between Water Use Efficiency And Light Use Efficiency In Four Row Crop Canopies, Meetpal S. Kukal, Suat Irmak Dr.

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Quantitative evidence of light use efficiency (LUE) controls on water use effi- ciency (WUE) is lacking, especially comparatively across row crops. Field research experiments (2016–2018) were set up for maize (Zea mays L.), soybean [Glycine max (L.) Merr.], sorghum [Sorghum bicolor (L.) Moench], and winter wheat (Triticum aestivum L.), under optimal growth conditions in dry sub-humid conditions. Overall, LUE was able to explain 52% of variance in WUE, and were related as WUE = 1.73 LUE, although crop-specific variation was observed. High- est sensitivity of WUE to changes in LUE was found in sorghum, followed by soybean, winter wheat, and …

Effect Of Urea Fertilizer Deep Placement Days After Transplanting Using Brri Prilled Urea Applicator On Transplanted Boro Rice Yield, Muhammad Rashed Al Mamun, K. Naher, Md Towfiqur Rahman, Md Anwar Hossen

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Rice is the most important crop in the developing countries of Asia. In the south and south-east Asia, rain-fed and irrigated transplanted rice occupies nearly two-thirds of the rice-growing area and produces more than 80% of the rough rice. In these areas, prilled urea conventionally applied by farmers is very insufficient in the transplanted rice field, where severe losses occur (up to 60% of applied N) via NH₃volatilization, denitrification, leaching, and runoff. Considering loss minimization, an experiment was conducted during the Boro season at Bangladesh Agricultural Development Corporation (BADC) in Sylhet to evaluate the performance of BRRI Prilled …

ค่าจลนพลศาสตร์ของการบำบัดน้ำเสียโดยเม็ดตะกอนจุลินทรีย์แบบใช้อากาศ, สรายุธ เตยโพธิ์

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้เป็นการศึกษาประสิทธิภาพ อัตราการบำบัด และค่าจลนพลศาสตร์ของการบำบัดน้ำเสียโดยเม็ดตะกอนจุลินทรีย์แบบใช้อากาศ โดยเดินระบบในถังปฏิกรณ์เอสบีอาร์ ใช้น้ำตาลทรายเป็นแหล่งคาร์บอน และแอมโมเนียมคลอไรด์เป็นแหล่งไนโตรเจน การเลี้ยงเม็ดตะกอนในถังปฏิกิริยาใช้ความเร็วในการเติมอากาศ 3.5 เซนติเมตร/วินาทีเป็นเวลา 5.7 ชั่วโมง เวลาตกตะกอน 15 นาที สัดส่วนการทดแทนน้ำเสียร้อยละ 60 ควบคุมพีเอชในระบบในช่วง 6.8-7.2 และค่าออกซิเจนละลายมากกว่า 2 มิลลิกรัม/ลิตร ตรวจวัดพารามิเตอร์ ได้แก่ ความเข้มข้นซีโอดี แอมโมเนียม ไนไตรต์ ไนเตรต ความเข้มข้นของตะกอนแขวนลอย (MLSS) ความสามารถในการตกตะกอนที่ 30 นาที (SV30) ค่าดัชนีปริมาตรตะกอน (SVI) ขนาดเม็ดตะกอน ความหนาแน่นของตะกอน การทดลองหาค่าจลนพลศาสตร์ใช้ความเข้มข้นซีโอดี 100-2,000 มิลลิกรัม/ลิตร และความเข้มข้นแอมโมเนียมไนโตรเจน 5-100 มิลลิกรัมแอมโมเนียมไนโตรเจน/ลิตร โดยศึกษาค่าอัตราการบำบัดจำเพาะสูงสุด (km) และความเข้มข้นที่อัตราการบำบัดเท่ากับครึ่งหนึ่งของอัตราการบำบัดจำเพาะสูงสุด (Ks) ของเม็ดตะกอนจุลินทรีย์แบบใช้อากาศ ผลการทดลองพบว่า ประสิทธิภาพการบำบัดซีโอดีและแอมโมเนียมไนโตรเจนสูงสุดของระบบที่ระยะเวลาบำบัด 6 ชั่วโมงเท่ากับร้อยละ 98.4 และ 99.6 ตามลำดับ ค่าดัชนีปริมาตรตะกอนเฉลี่ย 13.408±4.752 มิลลิลิตร/กรัม ค่าความเข้มข้นตะกอนจุลินทรีย์ (MLSS) ในถังปฏิกรณ์ที่ 1 อยู่ในช่วง 8,040-26,430 มิลลิกรัม/ลิตร ในถังปฏิกรณ์ที่ 2 อยู่ในช่วง 11,100-19,720 มิลลิกรัม/ลิตร ขนาดเม็ดตะกอนขนาดใหญ่ที่สุดที่มีการพบในระบบมีขนาดเท่ากับ 3 มิลลิเมตร ความหนาแน่นของตะกอนจุลินทรีย์เท่ากับ 1.1301±0.0283 กรัม/มิลลิลิตร ค่าอัตราการบำบัดในการบำบัดซีโอดีและแอมโมเนียมสูงสุดของระบบ (km) เท่ากับ 27.917±11.997 มิลลิกรัมซีโอดี/มิลลิกรัม MLVSS/วัน และ 11.353±0.619 มิลลิกรัมแอมโมเนียมไนโตรเจน/วัน ตามลำดับ และความเข้มข้นซีโอดีที่อัตราการย่อยสลายครึ่งหนึ่งของอัตราการย่อยสลายสูงสุด (Ks) เท่ากับ 963.04±685.817 มิลลิกรัม/ลิตร ความเข้มข้นแอมโมเนียมที่อัตราการย่อยสลายครึ่งหนึ่งของอัตราการย่อยสลายสูงสุด เท่ากับ 95.973±9.509 มิลลิกรัม/ลิตร ตามลำดับ

Removal Of Chemicals Of Emerging Concern And Mass Transfer Modeling In A Nanofiltration Membrane Process, Carlyn Higgins

Electronic Theses and Dissertations, 2020-2023

An investigation of 1,4-dioxane and enantiomeric ibuprofen mass transfer in a nanofiltration (NF) membrane process has been completed. Pilot-scale experiments using a 267 gallon per minute (gpm) split-feed, center-port NF process treating pH 6.5 groundwater revealed a consistent 12 percent removal of 1,4-dioxane despite the variable feed concentration (180 nanograms per liter (ng/L) to 38,400 ng/L) when the water flux and temperature were held constant. Bench-scale, flat-sheet NF membrane experiments treating pH 4.0 synthetic water displayed a 34.5 to 49.5 percent removal of racemic ibuprofen. Removal values were dependent on feedwater concentration (1 to 1,500 microgram per liter (µg/L)), pH, …

Within-Field Variability In Granular Matrix Sensor Data And Its Implications For Irrigation Scheduling, T. Lo, H.C. Pringle Iii, Daran Rudnick, Geng Bai, L. Jason Krutz, D.M. Gholson, Xin Qiao

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Even when located within the same field, multiple units of the same soil moisture sensor rarely report identical values. Such within-field variability in soil moisture sensor data is caused by natural and manmade spatial heterogeneity and by inconsistencies in sensor construction and installation. To better describe this variability, daily soil water tension values from 14-23 sets of granular matrix sensors during the middle part of four soybean site-years in the Mississippi Delta were analyzed. The soil water tension data were found to follow approximately normal distributions, to exhibit moderately high temporal rank stability, and to show strong positive correlation between …

Cationic Surfactant Analysis With Good Laboratory Practice, Lawrence K. Wang, Mu-Hao Sung Wang, Nazih K. Shammas, Valerie Renak, Yung-Tse Hung

Civil and Environmental Engineering Faculty Publications

The objectives of this research are to: (a) demonstrate how to select an organic solvent (such as 1,1,1-trichloroethane) for spectrophotometric determination of cationic surfactant in water and wastewater, (b) investigate and recommend possible better organic solvents for surfactant analysis; and (c) introduce good laboratory practice for personal protection, laboratory protection and hazardous waste management. Specifically this research involves selection of alternate less toxic and greener organic solvent for use in a methyl orange method for colorimetric determination of cationic surfactants in the 0.2 to 2.0 mg/L range. The principles, steps and management of the methyl orange method include: (a) complexation …

Initial Transformation Of Photo-Viable Free Amino Acids In The Presence Of Surrogate And Standard Dissolved Organic Matter Under Sunlit Irradiation, Ryan J. Kibler

Dissertations, Master's Theses and Master's Reports

With more than half of the nation’s drinking water affected by wastewater discharge from upstream and more indirect and direct reuse of treated wastewater, human health and ecotoxicological impacts resulting from effluent organic material (EfOM) will increase. Dissolved free amino acids (DFAAs), nitrogen components of EfOM, are essential nitrogen sources for microorganisms and play important roles in global N-cycling in natural aquatic environments. Several DFAAs including histidine, methionine, and tyrosine in sunlit surface waters are susceptible to direct and indirect photochemical transformation with reactive oxygen species. In this study, we investigated the reaction kinetics and initial reaction mechanisms involved in …

Life Cycle Information Models With Parameter Uncertainty Analysis To Facilitate The Use Of Life-Cycle Assessment Outcomes In Pavement Design Decision-Making, Chaitanya Ganesh Bhat

Dissertations, Master's Theses and Master's Reports

The objective of this dissertation is to develop Life Cycle Information Models (LCIMs) to promote consistent and credible communication of potential environmental impacts quantified through Life-Cycle Assessment (LCA) methodology. The introduction of Life Cycle Information Models (LCIMs) will shift the focus of pavement LCA stakeholders to collect reliable foreground data and adapt to consistent background data present within LCIMs. LCA methodology requires significant Life Cycle Inventory (LCI) data to model real world systems and quantify potential environmental impacts. The lack of guidance in ISO standards on consistently compiling LCI data and defining protocols for modeling lowers the reliability of LCA …

การประเมินศักยภาพโครงสร้างพื้นฐานสีเขียว: กรณีศึกษาคณะวิศวกรรมศาสตร์ จุฬาลงกรณ์มหาวิทยาลัย, พารณ มั่นใจอางค์

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้เป็นการศึกษาศักยภาพโครงสร้างพื้นฐานสีเขียวที่เกี่ยวข้องกับการจัดการน้ำฝนในพื้นที่เมือง ครอบคลุมโครงสร้างพื้นฐานสีเขียว 3 ระบบ ได้แก่ ระบบกักเก็บน้ำฝน หลังคาเขียว และคอนกรีตพรุน โดยพิจารณาศักยภาพในการลดปริมาณน้ำฝนที่ไหลลงท่อระบายน้ำ และศักยภาพในการลดปริมาณก๊าซเรือนกระจกจากการลดปริมาณน้ำเสียที่เข้าสู่ระบบบำบัด ลดปริมาณการใช้น้ำประปา และการช่วยอนุรักษ์พลังงานของมาตรการดังกล่าว โดยใช้ข้อมูลปริมาณฝนที่ตกในพื้นที่กรุงเทพมหานครจากกรมอุตุนิยมวิทยา ย้อนหลังเป็นเวลา 10 ปี ตั้งแต่ปี พ.ศ. 2551 – 2560 และใช้โปรแกรม Open studio ซึ่งมีฐานข้อมูลของ EnergyPlus รุ่น 8.9.0 ในการจำลองการใช้พลังงานของอาคาร รวมทั้งประเมินความคุ้มค่าทางเศรษฐศาสตร์ในระยะเวลาโครงการ 50 ปี โดยมีคณะวิศวกรรมศาสตร์ จุฬาลงกรณ์มหาวิทยาลัย เป็นพื้นที่กรณีศึกษา ผลการศึกษาพบว่า ระบบกักเก็บน้ำฝน ขนาดความจุ 40 ลูกบาศก์เมตร สามารถลดปริมาณน้ำฝนที่ไหลลงท่อระบายน้ำและลดปริมาณก๊าซเรือนกระจกได้มากที่สุดในขณะที่มูลค่าปัจจุบันสุทธิยังเป็นบวกนั่นคือจะได้ผลประโยชน์ทางเศรษฐศาสตร์ด้วย จึงควรได้รับพิจารณาทำก่อนเป็นอันดับแรก ส่วนโครงสร้างพื้นฐานสีเขียวอื่นๆ นั้นจะต้องมีค่าใช้จ่ายเพิ่มเติม สำหรับหลังคาเขียว เป็นโครงสร้างพื้นฐานสีเขียวที่สามารถลดปริมาณน้ำฝนที่ไหลลงท่อระบายน้ำและลดปริมาณก๊าซเรือนกระจกได้มากที่สุดแต่ก็มีต้นทุนที่สูงที่สุดเช่นกัน ขณะที่คอนกรีตพรุน เหมาะกับการใช้ประโยชน์ในการจัดการน้ำฝนแต่ไม่แนะนำสำหรับจุดประสงค์ในการลดปริมาณก๊าซเรือนกระจก

A Field Study Of Bioaccessible Lead In Detroit Soils: Insight Into The Effectiveness Of Phosphate-Based Lead Sequestration, Sabrina R. Good

Wayne State University Theses

Historical and contemporary use of lead (Pb) in gasoline, paints, and industry have caused lead to be ubiquitous in the urban soil environment, disproportionately affecting low-income minority children. As soil is a major exposure pathway for children, an effective remediation technique for lead-contaminated soil is urgently needed. Common remediation techniques, such as excavation or soil capping, are expensive and environmentally destructive, especially on a city-wide residential basis. Decreasing the bioavailability of lead, or the fraction which is retained by the human body, may be a more economically and environmentally conscious option for remediating lead in urban environments.

Research has demonstrated …

An Investigation Into Solid Waste Problem In The Egyptian Construction Industry: A Mini-Review, Ahmed Osama Daoud, Ayman Ahmed Ezzat Othman, Herbert Robinson, Ali Bayyati

Architectural Engineering

Solid waste management (SWM) is one of the most critical global challenges nowadays. It has a severe negative effect on the triple bottom line of sustainability. Construction and demolition waste (CDW) contributes about 50% of the total global annual generated SW. In the particular case of the Middle East and North Africa (MENA) region including Egypt, the SW problem has become a major challenge, and the need to find sustainable solutions is overwhelming. However, the region faces several challenges that hinder the development of an effective and efficient SWM system. This has resulted in the predominance of unsustainable SWM practices …

Water Reclamation Using Functionalized Forward Osmosis Membrane, Fnu Joshua

Electronic Theses and Dissertations, 2020-2023

This study investigated water reclamation from an impaired-quality water using forward osmosis (FO) membrane functionalized by nano zero valent iron (nZVI) loaded polyelectrolyte multilayer films. Stormwater runoff was selected as the impaired-quality water, which served as a feed solution (FS) and a NaCl salt solution at a concentration representing reverse osmosis (RO) concentrate was used a draw solution (DS). RO concentrate is another impaired-quality water that is discharged to the environmental with little or no treatment. A commercial cellulose triacetate (CTA) FO membrane was modified using poly allylamine hydrochloride (PAH) (a polycation) and poly acrylic acid (PAA) (a polyanion) following …

Development And Application Of A Performance And Operational Feasibility Guide To Facilitate Adoption Of Soil Moisture Sensors, Meetpal S. Kukal, Suat Irmak, Kiran Sharma

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Soil moisture sensors can be effective and promising decision-making tools for diverse applications and audiences, including agricultural managers, irrigation practitioners, and researchers. Nevertheless, there exists immense adoption potential in the United States, with only 1.2 in 10 farms nationally using soil moisture sensors to decide when to irrigate. This number is much lower in the global scale. Increased adoption is likely hindered by lack of scientific support in need assessment, selection, suitability and use of these sensors. Here, through extensive field research, we address the operational feasibility of soil moisture sensors, an aspect which has been overlooked in the past, …

Effects Of Farrowing Stall Layout And Number Of Heat Lamps On Sow And Piglet Production Performance, Suzanne M. Leonard, Hongwei Xin, Tami M. Brown-Bandl, Brett C. Ramirez, Somak Dutta, Gary A. Rohrer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Most farrowing facilities in the United States use stalls and heat lamps to improve sow and piglet productivity. This study investigated these factors by comparing production outcomes for three different farrowing stall layouts (traditional, expanded creep area, expanded sow area) and use of one or two heat lamps. Data were collected on 427 sows and their litters over one year. Results showed no statistical differences due to experimental treatment for any of the production metrics recorded, excluding percent stillborn. Parity one sows had fewer piglets born alive (p < 0.001), lower percent mortality (p = 0.001) and over-lay (p = 0.003), and a …

Teacher Level Factors And Student Achievement In A Cyber-Enabled Engineering Education Professional Development Program, Wei Zakharov, Johannes Strobel, Heidi A. Diefes-Dux

Department of Agricultural and Biological Systems Engineering: Faculty Publications

This study investigates the impact of an elementary engineering education teacher professional development program on student learning. The results show a significant increase in students’ knowledge in science from pre- to post-test as well as in engineering design from grade two to grade four. Further, the study uses multilevel modeling to quantitatively analyze the impact of differences among teachers on the engineering design achievement of their students. Different predictive relationships between demographic and social capital factors at the teacher level and student achievement are identified and implications for educational policymaking and practices are discussed.

Present Mechanization Of Regional Tea Processing And Grading System In Bangladesh, Md Towfiqur Rahman, Marwa Rahman, Kaswar Hamid, Sabiha Ferdous, Muhammad Rashed Al Mamun

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Nowadays tea is the most popular beverage crop of Bangladesh which contributes to our national GDP. There are 166 tea gardens in the various region in Bangladesh are producing tea. Some best quality tea is exporting from our country but this amount is negligible due to improper handling and processing systems. Quality tea production from processing houses is beyond control and mostly depends on the processing method. Improper handling and insufficient technology results in lower grade tea, as well as foreign contaminates, are found in made tea. This research focused on the problems of the present of tea processing and …

Recovery Of Ethyl Lactate From Washing Solution Originating From Drill Cuttings Treatment By Adsorption Process, Theary Peng Orng

Chulalongkorn University Theses and Dissertations (Chula ETD)

The purpose of this study was to recover the washing solutions generated from drill cuttings washing process using an adsorption technology. Ethyl lactate (EL) was selected as an extracting agent for drill cuttings washing throughout the work. Various washing parameters including liquid-to-solid (L/S) ratio, washing time, mixing speed, rinse-to-solid (R/S) ratio, and rinsing time were studied with the aid of response surface methodology. Once the optimal washing conditions were obtained, the recovery of washing solutions, i.e., spent EL and rinsed water using the commercial granular activated carbon (GAC) and kapok fiber (KF) were investigated. Finally, the adsorbent modification and validation …

Remediation And Prevention Of Harmful Algae Blooms (Habs) In Ascarate Lake At El Paso, Texas, Elizabeth Herrera Ortega

Open Access Theses & Dissertations

Ascarate park in El Paso, Texas is an example of an urban ecosystem in the middle of a growing city. It is the largest public-use recreational park in El Paso county and it includes a 48-acre Ascarate lake. The purpose of this study was to prevent harmful algae growth in Ascarate lake using phytoremediation by analyzing different water quality parameters. We installed artificial islands on west cove of the lake with African iris plants to determine the feasibility of remediation to prevent algae blooms in Ascarate lake. Water samples were collected at different points close and away from the islands …

Removal Of Heavy Metals From Landfill Leachate Using Electrospun Polyelectrolyte Complex Fiber-Laminated Ultrafiltration Membrane, Amirsalar Rabbani Esfahani

Electronic Theses and Dissertations, 2020-2023

Ultrafiltration (UF) is a low-pressure membrane process that yields higher permeate flux and saves significant operating costs compared to NF/RO. However, UF has not been applied as a primary method for landfill leachate treatment due to its large pore size. This research investigated the removal of heavy metals from landfill leachate using an UF membrane laminated with fiber mats produced from electrospinning of a polyelectrolyte complex. In this research, we modified the surface of the UF membrane with two polyelectrolytes including Polyacrylic Acid (PAA) and Polyallylamine Hydrochloride (PAH). The removal of heavy metals including Pb, Cd, and Cu from water …

Fluvial Sediment Organic Matter Degradation Identified With Elemental And Isotopic Fate During Laboratory Incubation, Brenden Riddle

Theses and Dissertations--Civil Engineering

Fluvial sediment is well recognized as a critical factor in both carbon and nutrient budgets within stream systems. However, we find very few studies of reactivity and isotope enrichment for stream water from agricultural and urban streams and the class of substrate known as fluvial sediment organic matter. This study investigated the hypothesis that fluvial sediment is subject to degradation even though many previous studies have considered this class of substrate generally inert. Therefore we qualify that elemental and isotopic signatures of fluvial sediment organic matter should be considered potentially non-conservative when used in tracer studies. Methods applied to this …

Probabilistic Approach To Water, Sediment, And Nutrient Connectivity For Advancing Watershed Modelling, David Tyler Mahoney

Theses and Dissertations--Civil Engineering

The goal of this dissertation is to represent the spatial and temporal domains of water, sediment, and nutrient flux and pathways within fluvial and watershed settings. To complete this goal, we integrate connectivity theory into watershed model structures to simulate water, sediment, and nutrient movement at the fundamental unit they occur. Fluvial-based sediment and nutrient flux is an important driver of global sediment and nutrient budgets, and the quantification of which serves as an ongoing challenge to limnologists, engineers, and watershed managers. Watershed models have been richly developed over the past century, but are currently restrained by problems related to …

A Modeling Approach To Understanding Glyphosate Transport In The Belize River Watershed, Barbara Anmei Astmann

Theses and Dissertations--Civil Engineering

Glyphosate is the most widely used herbicide worldwide and is often transported from application areas to surface water when solubilized in runoff or sorbed to eroded sediment. There is evidence that suggests both glyphosate and its main metabolite aminomethylphosphonic acid (AMPA) may pose a risk to human health, as well as cause adverse effects in the environment. However, consistent monitoring data is still limited, especially in developing countries. Belize is a developing nation with agriculture being a major sector of its economy and is heavily reliant on glyphosate. The widespread use of glyphosate in Belize may be resulting in glyphosate …

Variance Decomposition Of Forecasted Water Budget And Sediment Processes Under Changing Climate In Fluvial And Fluviokarst Systems, Nabil Al Aamery

Theses and Dissertations--Civil Engineering

Variance decomposition is the partitioning of different factors affecting the variance structure of a response variable. The present research focuses on future streamflow and sediment transport processes projections as the response variables. The authors propose using numerous climate factors and hydrological modeling factors that can cause any response variable to vary from historic to future conditions in any given watershed system. The climate modeling factors include global climate model, downscaling method, emission scenario, project phase, bias correction. The hydrological modeling factor includes hydrological model parametrization, and meteorological variable inclusion in the analysis. This research uses a wide spectrum of data, …

Investigation Into The Presence, Persistence, And Fate Of S. Aureus, And Its Mobile Genetic Elements, In Wastewater And The Surrounding Environment, Atena Amirsoleimani

Theses and Dissertations--Civil Engineering

Currently, the world is engaged in a battle against very small parts of our environment that develop and share genes for resistance to multiple environmental conditions. Pathogenic infections caused by antibiotic-resistant bacteria have been impacting animal and human health and life. Increasing incidences of methicillin- resistant Staphylococcus aureus (MRSA) infections transmitted through the environment are rising faster than the discovery of new antibiotics. Multi-drug resistant S. aureus infections in healthy individuals without prior hospitalization have been increasing all around the world.

Many people carry S. aureus in their nose and on their skin, common niches for the bacteria to co-grow …

Soil Bulk Density Effects On Runoff Estimation, Colton Pugh

Theses and Dissertations--Biosystems and Agricultural Engineering

Urbanization has long been a major factor in the hydrology of surrounding areas. Engineers are commonly tasked with mitigating the extra runoff that urbanization brings with it. The NRCS Curve Number (CN) method is a commonly-used approach to predicting the amount of runoff that will be experienced from a given area. However, this method is known to be highly simplified in model of the processes involved. This study focused on determining the relationships between soil bulk density, simulated rainfall events, hydrologic soil group (HSG) and runoff estimation (specifically via the NRCS CN method). It was determined that soil bulk density …

Quantifying Nitrogen Fate In Karst Agroecosystem Streams Of Central Kentucky: Development And Application Of Numerical Modeling And Insight From High-Resolution Sensors, Nolan Lewis Bunnell

Theses and Dissertations--Biosystems and Agricultural Engineering

In-stream fate of nutrients in karst agroecosystems remains poorly understood, despite the known impact of karst on water resources at local to global scales. In the Inner-Bluegrass region of central Kentucky, heterogeneity of karst maturity, flow pathways, and nutrient sources adds to the complexity of quantifying nutrient dynamics, thus requiring novel monitoring and modeling approaches. The significance of these streams is recognized given spring/surface water confluences have been identified as hotspots for biogeochemical transformations. In slow-moving streams high in dissolved inorganic nutrients (particularly dissolved inorganic nitrogen (DIN) and dissolved reactive phosphorus (DRP)), benthic and floating aquatic macrophytes are recognized to …