Environmental Engineering Commons^™

Silver Nanoparticle Transport Through Soil: Illuminating The Governing Pore-Scale Processes, Ian L. Molnar

Electronic Thesis and Dissertation Repository

Engineered nanoparticles are widely used and will eventually be released to the subsurface environment and contaminate groundwater resources. However, the transport of engineered nanoparticles through soil is currently not well understood and cannot be modelled in any fundamental manner, placing groundwater resources at risk from nanoparticle contamination. This inability to accurately simulate transport is due to a lack of experimental information on nanoparticle interactions in the pore spaces of real soils.

This thesis illuminates the pore-scale processes governing silver nanoparticle transport through soil. In addition, it examines the influence of surface chemistry and grain/pore distributions on those processes. For the …

Monitoring And Modeling The Hydrological Performance Of Extensive Green Roof Systems, Joseph Seidl

Theses and Dissertations

Urban stormwater runoff causes many problems for watersheds located within large metropolitan areas, including such detrimental effects as flooding, erosion, pollution, and the increased risk of combined sewerage overflows. Increased amounts of impervious areas resulting from urban sprawl have also been shown to escalate stormwater flows, which exacerbates water management issues in these metropolitan areas. Water resource engineers have progressively turned toward green infrastructure to solve stormwater problems, and green roof systems represent one type of this green infrastructure. As of current, however, green roof systems are largely underused in as an effective stormwater management tool.

The major factor limiting …

Evaluation Of First Order Error Induced By Conservative-Tracer Temperature Approximation For Mixing In Karstic Flow, Philippe Machetel, David A. Yuen

Sinkhole Conference 2015

Fluid dynamics in karst systems is complex due to the heterogeneity of hydraulic networks that combine the Porous Fractured Matrix (PFM) and the interconnected drains (CS). These complex dynamic systems often need to be treated as “black boxes” in which only input and output properties are known. In this work, we propose to assess the first-order error induced by considering the temperature as a conservative tracer for flows mixing in karst (fluvio-karst). The fluvio-karstic system is treated as an open thermodynamic system (OTS), which exchanges water and heat with its surrounding. We propose to use a cylindrical PFM drained by …

Karst Spring Cutoffs, Cave Tiers, And Sinking Stream Basins Correlated To Fluvial Base Level Decline In South-Central Indiana, Garre A. Conner

Sinkhole Conference 2015

The Mitchell Aquifer averages 80m in thickness and underdrains a karst region in the Crawford Upland and Mitchell Plateau region in south-central Indiana (110,000 km2). The Springville Escarpment is a transitional boundary between the upland and plateau. Cave stream linking between cave tiers in the aquifer and correlation of cave tier inception horizons to a base level decline surface is interpreted for the Kirby Watershed, encompassing the prekarst headland of Indian Creek (42km2). The watershed was severed from lower Indian Creek at Eller Col by limestone cavern drainage on the ridge between White River and East Fork. Correlation of recharge …

Tracer Studies Conducted Nearly Two Decades Apart Elucidate Groundwater Movement Through A Karst Aquifer In The Frederick Valley Of Maryland, Keith A. White, Michael K. Cobb, Thomas Aley, Ethan Weikel

Sinkhole Conference 2015

A pair of groundwater tracer studies at a single karst test site were completed 18 years apart. The results of these studies have provided evidence of both relatively rapid advective transport via conduits and an extreme capacity for dye storage and retardation. The tracer results, coupled with other subsurface investigation data, are used to develop a conceptual model for groundwater movement through this karst aquifer in the Frederick Valley of Maryland, as well as identify implications for remediation. Three fluorescent tracer dyes used in the initial study were detected in several background monitoring locations established for the second study conducted …

Field Scale Application Of Nanoscale Zero Valent Iron: Mobility, Contaminant Degradation, And Impact On Microbial Communities, Chris M.D. Kocur

Electronic Thesis and Dissertation Repository

This thesis began by verifying that nanoscale zero valent iron (nZVI) synthesis methods could be scaled up and implemented at the field scale in a safe manner. This led to successful demonstration of nZVI injection and mobility under constant head gravity injection into a contaminated utility corridor in Sarnia, Ontario. Where field studies have fallen short in the past was linking the somewhat qualitative field geochemical parameters to other evidence of nZVI transport. Definitive nZVI detection was elusive in previous field studies due to the highly reactive nature of the particles caused by their high surface area. nZVI was detected …

A Soil Parameters Geodatabase For The Modeling Assessment Of Agricultural Conservation Practices Effects In The United States, Mauro Di Luzio, Martin L. Norfleet, Jeffrey G. Arnold, Jimmy R. Williams, James R. Kiniry

International Journal of Geospatial and Environmental Research

Soil parameters for hydrology modeling in cropland dominated areas, from the regional to local scale, are part of critical biophysical information whose deficiency may increase the uncertainty of simulated conservation effects and predicting potential. Despite this importance, soil physical and hydraulic parameters lack common, wide-coverage repositories combined to digital maps as required by various hydrology-based agricultural water quality models.

This paper describes the construction of a geoprocessing workflow and the resultant hydrology-structured soil hydraulic, physical, and chemical parameters geographic database for the entire United States, named US-SOILM-CEAP. This database is designed to store a-priori values for a suit of models, …