Environmental Engineering Commons^™

Hydroclimate Drivers And Atmospheric Dynamics Of Floods, Nasser Najibi

Dissertations and Theses

Our preliminary survey showed that most of the recent flood-related studies did not formally explain the physical mechanisms of long-duration and large-peak flood events that can evoke substantial damages to properties and infrastructure systems. These studies also fell short of fully assessing the interactions of coupled ocean-atmosphere and land dynamics which are capable of forcing substantial changes to the flood attributes by governing the exceeding surface flow regimes and moisture source-sink relationships at the spatiotemporal scales important for risk management. This dissertation advances the understanding of the variability in flood duration, peak, volume, and timing at the regional to the …

Minimizing Trihalomethane Formation Through Source Water Monitoring And Optimizing Treatment Practices, Nashid Mirza

Graduate Theses, Dissertations, and Problem Reports

Trihalomethanes, a family of halogenated disinfection byproducts, are prevalent in finished drinking water. According to USEPA’s Disinfectants and Disinfection Byproducts Rules (DBPRs), the regulatory standard of the total trihalomethanes (TTHMs) is 80 μg/L, and water treatment plant operators are required to closely monitor TTHMs in the finished water on a quarterly basis. Although total organic carbon (TOC) has been identified as a precursor for the TTHMs, knowledge gaps still exist in how specific water and treatment related factors (e.g., intake water quality, seasonal variation, contact time, and treatment train) affect TTHMs formation. Focusing on water treatment plants in southwestern Pennsylvania, …

Incorporation Of Contaminated Sediment Into Environmentally Safe Concrete, Andrew Needs

Williams Honors College, Honors Research Projects

The research performed through this project provided some interesting results on how the different properties of the contaminated sediment can impact the strength of the new concrete.

Average three, seven, and fourteen-day strengths increased when comparing to the baseline mix developed for the experiment. Increases in strengths were notices in the ten and twenty-five percent soil replacement mixes. The largest increase was approximately thirty-three percent greater than the baseline average.

The results from the forty percent replacement test showed a significant decrease in strengths when comparing against the baseline mix. A loss of about thirty percent was observed between the …

The Operational And Safety Effects Of Heavy Duty Vehicles Platooning, Ahmed Alzahrani

UNF Graduate Theses and Dissertations

Abstract

Although researchers have studied the effects of platooning, most of the work done so far has focused on fuel consumption. There are a few studies that have targeted the impact of platooning on the highway operations and safety. This thesis focuses on the impact of heavy-duty vehicles (HDVs) platooning on highway characteristics. Specifically, this study aims at evaluating the effects of platooning of HDVs on capacity, safety, and CO₂ emissions.

This study is based on a hypothetical model that was created using the VISSIM software. VISSIM is a powerful simulation software designed to mimic the field traffic flow …

Escherichia Coli Removal From Stormwater Using Steel Chips Filter, Peng Dai

Electronic Theses and Dissertations

Media filtration has received increasing attention as an effective technology that can facilitate the removal of particles and dissolved pollutions in the stormwater. However, most traditional media filtration systems are generally ineffective in removing bacteria, causing pollution of groundwater and receiving surface water. In this study, recycled steel chips were evaluated as low-cost filter materials for bacterial removal from stormwater. Laboratory column experiments were conducted to evaluate the impact of steel chips particle size, flow rate, initial E.coli concentration, pH, natural organic matter (NOM), steady and intermittent flow on E.coli removal. The results showed that E.coli removal decreased from 99.4% …

Decomposing A Watershed’S Nitrate Signal Using Spatial Sampling And Continuous Sensor Data, Evan Clare

Theses and Dissertations--Civil Engineering

Watershed features, physiographic setting, geology, climate, and hydrologic processes combine to produce a time-variant nutrient concentration signal at the watershed outlet. Anthropogenic influences, such as increased agricultural pressures and urbanization, have increased overall nutrient loadings delivered to the fluvial network. The impact of such increased nutrient loadings on Kentucky’s drinking water remains a potential threat to the region.

By coupling spatial sampling of nitrate concentrations in surface water with contemporary nutrient and water quality sensor technology, a decomposition of the Upper South Elkhorn watershed’s nitrate signal and an estimation of source timing and loading in the watershed was completed. The …