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Full-Text Articles in Engineering
Effect Of Land Use Type And Stormwater Control Measures On Non-Point Source Phosphorus Concentrations And Loads In A Cold Climate Urban Subwatershed, Dillon H. Vyn
Electronic Thesis and Dissertation Repository
Non-point source phosphorus (P) exports from urban areas including contributions from different urban land use types and seasonal variations are not well understood, especially for cold climates. Additionally, the effectiveness of different stormwater control measures (SCMs) in reducing P concentrations and loads are poorly quantified with assessments rarely considering total watershed P loads. To address these gaps, detailed field monitoring of total P (TP), soluble reactive P (SRP), total suspended solids (TSS), and water quantity was conducted over a 19-month period in a mixed urban watershed in London, ON. Monitoring sites were located at watershed outlets, at the outlets of …
Exploring Valuable And Potentially Harmful By-Products Formed And/Or Released From Smouldering Treatment Of Sewage Sludge, Taryn Ashley Fournie
Exploring Valuable And Potentially Harmful By-Products Formed And/Or Released From Smouldering Treatment Of Sewage Sludge, Taryn Ashley Fournie
Electronic Thesis and Dissertation Repository
The presence of potentially toxic elements (PTEs) and emerging contaminants (e.g., per- and polyfluoroalkyl substances (PFAS)) makes sewage sludge management challenging. Due to their hazards, there is significant interest in thermal treatment technologies that can destroy these compounds, like incineration. However, incineration still poses several risks due to forming and/or releasing hazardous emissions (e.g., polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and PTEs). More recently, the use of smouldering has been introduced as a potential treatment technique for managing sewage sludge. Smouldering presents several advantages over traditional incineration due to its lower energy and pre-treatment requirements and potential for beneficial …
Evaluation Of The Impacts Of De-Icing Salts On The Performance Of Bioretention Media In Retaining Phosphorus From Urban Stormwater, Brennan S. Donado Visbal
Evaluation Of The Impacts Of De-Icing Salts On The Performance Of Bioretention Media In Retaining Phosphorus From Urban Stormwater, Brennan S. Donado Visbal
Electronic Thesis and Dissertation Repository
Bioretention systems are a low impact development system that can remove pollutants such as phosphorus (P) from urban stormwater. P retention in bioretention systems is complicated in cold climate regions due to factors such as inputs of road de-icing salts. This study evaluates the impact of prolonged and periodic salt inputs on P retention by conducting column experiments using three different bioretention media with and without an amendment added. Non-amended columns showed net P release, whereas amended columns showed net P retention. While some non-amended columns showed prolonged salt exposure increases P release, the largest P release for all columns …
Spatio-Temporal Variability Of Phosphorus Near The Groundwater-Stream Interface, Meghan Vissers
Spatio-Temporal Variability Of Phosphorus Near The Groundwater-Stream Interface, Meghan Vissers
Electronic Thesis and Dissertation Repository
Agricultural practices can cause excess inputs of soluble reactive phosphorus (SRP) to freshwater catchments leading to eutrophication. This study evaluates spatio-temporal variability of SRP in an agricultural streambed including the influence of groundwater-stream interactions, and examines the associated geochemical and hydrological controls. High porewater SRP (>1000 µg/L) and high SRP sediment fractions were observed in low groundwater discharge zones, specifically in the shallow (≤ 0.1 m) streambed sediments. Porewater SRP concentrations were linked to iron redox cycling with SRP concentrations concordant with more reducing conditions. Porewater SRP varied temporally but distinct seasonal changes were not observed. The conditions in …
Assessment Of The Performance Of Field-Scale Bioretention Systems To Reduce Phosphorus Loads From Urban Stormwater, Jaeleah J. Goor
Assessment Of The Performance Of Field-Scale Bioretention Systems To Reduce Phosphorus Loads From Urban Stormwater, Jaeleah J. Goor
Electronic Thesis and Dissertation Repository
High nutrient loading can degrade surface water quality worldwide. Bioretention systems are low impact development stormwater management features designed to remove pollutants, including phosphorus (P), from urban stormwater runoff. In this study, two field-scale bioretention systems installed in London, Ontario, Canada were monitored to develop detailed understanding of P behaviour and the hydro-biogeochemical mechanisms that govern overall P retention. Net retention of total P and dissolved organic P, and net release of soluble reactive P (SRP) and total dissolved P were observed. Prolonged input of road de-icing salts (NaCl) in winter and early spring may result in high P release …
Quantification Of Septic System Contribution To Nutrient Loads In Surface Waters, Archana Tamang
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 …
Estimation Of Nutrient Loads From Septic Systems To Tributaries In The Lake Erie Basin, Lauren Oldfield
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, …
Hydrology And Phosphorus Model For Agricultural Watershed: Swat Simulation Of Discharge And Nutrient Flux In The Medway Creek Watershed, Omar El Abusanina
Hydrology And Phosphorus Model For Agricultural Watershed: Swat Simulation Of Discharge And Nutrient Flux In The Medway Creek Watershed, Omar El Abusanina
Electronic Thesis and Dissertation Repository
High nutrient concentrations in surface water have been a serious concern that impacts water quality and ecology. High Phosphorus levels in Medway Creek indicate the presence of a pollution source in the watershed that needs to be identified and quantified. To investigate this issue, the Soil and Water Assessment Tool (SWAT) program has been used in this study with the Geographic Information System (GIS) to model the Medway Creek watershed and assess stream flow and nutrient flux. In this research, the SWAT model has been built, calibrated, and validated using two independent observed data sets to evaluate the SWAT efficiency …