Engineering Commons^™

Quantification Of Septic System Contribution To Nutrient Loads In Surface Waters, Archana Tamang

Electronic Thesis and Dissertation Repository

Freshwater systems worldwide are threatened by excessive nutrient (nitrogen and phosphorus) loading. This study evaluated the contribution of septic systems to stream nutrient loads in nine subwatersheds. Stream sampling was conducted during low and high discharge conditions, with samples analyzed for total phosphorus (TP), soluble reactive phosphorus (SRP), nitrate (NO₃-N), and acesulfame (ACE; wastewater tracer). Higher septic effluent reached the subwatershed outlets during high discharge conditions. Subwatersheds with newer households had a lower percentage of septic effluent reaching the stream compared with subwatersheds with older households. Seasonal and event-based ACE concentration-discharge relationships revealed that the hydrological pathways delivering …

Field-Scale Implementation Of Sulfidated Nano Zerovalent Iron For In-Situ Remediation, Ariel Nunez Garcia

Electronic Thesis and Dissertation Repository

As far back as the mid-1990s, biogenic sulfidation has been observed during the implementation of iron-based materials for groundwater remediation. This phenomenon has largely been a consequence of natural biogeochemical processes and the prospects of utilizing engineered sulfidated zerovalent iron (ZVI) particles – nano- and/or micro- sized – were not extensively explored. More recently sulfidation of zerovalent iron (ZVI) particles has received considerable attention, highlighting the benefits that engineered/abiotic sulfidation can offer to nZVI, but to date, no field demonstration of the technology has been conducted. The first part of this thesis aims to report the unique challenges and unanswered …

Estimation Of Nutrient Loads From Septic Systems To Tributaries In The Lake Erie Basin, Lauren Oldfield

Electronic Thesis and Dissertation Repository

Septic systems are often cited as an important source of nutrient loading to surface waters; however, there is limited quantitative evidence supporting this. To address phosphorus (P) load reduction targets for Lake Erie that were set by the Canadian and United States governments, there is a need to quantify the contribution of septic systems to P tributary loads. Doing so is challenging due to the diffuse nature of this nonpoint source, the lack of septic system inventory across Ontario, and the complexity of P transport in the environment. In this study, the artificial sweetener acesulfame, a tracer for human wastewater, …

Analysis And Control Of Aluminum Concentration In Groundwater: Mathematical Modelling And Laboratory Study, Daria Popugaeva

Electronic Thesis and Dissertation Repository

The remediation of metal-contaminated natural water bodies is prioritized due to metals toxicity, non-biodegradable properties, and accumulative behaviours leading to the increased incidence of adverse health effects. Current investigation is driven by the existing problem of elevated aluminum concentrations in the groundwater of Khibiny alkaline massif (Kola Peninsula). The prohibitive aluminum level exceeding the accepted standard of 0.20 mg L⁻¹ is described as a serious health concern when the groundwater used for the local water supply. The results of comprehensive field data analysis based on chemometric methods applied to the available monitoring data including 12 groundwater quality parameters are …

Enumeration, Variability, And Transport Of Escherichia Coli In The Foreshore Reservoir And Surface Water At Freshwater Beaches, Laura J. Vogel

Electronic Thesis and Dissertation Repository

Beaches are of immense recreational, societal and economic value. This value, however, is considerably diminished by poor water quality. Fecal indicator bacteria (FIB) are measured at recreational beaches worldwide to assess the water quality. A beach closure or advisory is issued if FIB concentrations in surface water exceed recreational water quality standards. Due to the lengthy time required to enumerate FIB (24 – 96 hours), statistical and mechanistic models have been developed to predict water quality exceedances a priori and to better understand why and under what conditions water quality exceedances occur. These models as well as beach water quality …

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 …