Engineering Commons^™

Biodegradability Of Cellulose And Its Impact On Oxygen Transfer Efficiency And Biological Nutrients Removal, Ahmed Shawki Ahmed

Electronic Thesis and Dissertation Repository

Cellulose from toilet paper is a significant fraction of particulate organics, which is recoverable. For the first time, comprehensive mapping and tracking the fate of cellulose across various unit processes at full-scale in two water resource recovery facilities located in North America and Europe was undertaken. The influent cellulose content accounted for approximately one-third of the total suspended solids (TSS). More than 80% of the raw wastewater cellulose was captured in primary treatment. The high cellulose content of the primary sludge accounting for 17%-35% of the TSS facilitates cellulose recovery. Cellulose biodegradation efficiency varied between 70%-90% of the primary effluent, …

Uncertainties In The Assessment Of Individual And Compound Flooding From River Discharge And Coastal Water Levels Under Climate Change, Shuyi Wang

Electronic Thesis and Dissertation Repository

It is widely recognized that climate change can impact the risks of flooding in many regions around the world especially the low-lying coastal areas. The concurrent occurrence of multiple flood drivers such as high river flows and coastal water levels can aggravate such impacts causing catastrophic damages. In this study, the individual and compounding effects of riverine and coastal flooding are investigated over Stephenville Crossing, a town located in the coastal-estuarine region of Newfoundland and Labrador (NL), Canada. The impacts of climate change on flood characteristics and the corresponding uncertainties associated with model inputs and structure, and emission scenarios are …

Effect Of The C-Source And Cod/N On Nitrite And Partial Nitrate Denitrification, Ahmed Fathy Elyas Badia

Electronic Thesis and Dissertation Repository

The main objectives of this study were: (i) to investigate dynamic specific denitrification rates (SDNR) from nitrite at various chemical oxygen demand (COD) / nitrogen (N) ratios using municipal wastewater (MWW) and acetate, and to study the kinetic parameters, (ii) to investigate the dynamic specific denitrification rates (SDNRs) from nitrite at various COD/N ratios in a system that uses methanol as a complementary carbon source, and studying the effect in case if nitrate replaced nitrite, and (iii) to investigate and compare between the nitrite shunt and N-PDN-anammox technologies through studying the dynamic specific denitrification rates (SDNRs) from nitrate and nitrite …

Chemically Enhanced Primary Treatment: Modelling And Resources Recovery, Wenjuan Mu

Electronic Thesis and Dissertation Repository

The chemically enhanced primary treatment (CEPT) process is gaining momentum for carbon redirection, thereby lowering the downstream liquid train load and maximizing energy recovery from the primary sludge. CEPT technique enhances coagulation and flocculation, that enable faster settling of particulate and colloidal solids and dissolved ions such as phosphate to enhance removal efficiency. Comprehending the dynamic behaviour of CEPT clarifiers is critical to not only develop a reliable whole plant simulation but also fully understand the efficacy of the treatment plant performance. To achieve such purposes, a great amount of efforts has been contributed to the advancement of primary clarifier …

Performance Of A Drinking Water Treatment System For A Small Community In Rural Ghana, West Africa, Xiya Xu

Electronic Thesis and Dissertation Repository

In many African countries, the shortage of water resources is a common phenomenon. Providing safe and adequate water is an issue that must be considered by community leaders and municipal authorities. The present project investigated the performance of a small drinking water treatment system in a small community at Enyan Abaasa, Central Region, Ghana, through sampling and laboratory testing. The treatment system, which is fed by a deep borehole, consists sequentially of polypropylene (PP) yarn pre-filter, sand filter, layered activated carbon-softener resin filter, PP yarn micron filter, reverse osmosis (RO) membrane, PP yarn final filter and two ultraviolet (UV) disinfection …

Sustainable Smouldering For Waste-To-Energy: Scale, Heat Losses, And Energy Efficiency, Tarek L. Rashwan

Electronic Thesis and Dissertation Repository

Applied smouldering combustion is emerging as a highly energy efficient approach towards waste-to-energy. This thesis aims to better understand this potential by addressing a critical knowledge gap between laboratory scale smouldering research and large-scale applications. Altogether, new understanding in provided on the complex and dynamic interactions between the reaction zone (smouldering front) and the cooling zone (treated inert porous media) by integrating theory, experiments, analytical modelling, and global energy balance calculations. The experiments spanned a range of reactor sizes and smouldering conditions (from weak to robust) with dry (carbon) and wet (sludge) fuels mixed in sand. This work revealed that …

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 …

Biomechanics Of Trees Under Extreme Wind Loading Events, Mojtaba Dargahi

Electronic Thesis and Dissertation Repository

For urban planners, arborists and foresters, understanding tree stability under self-weight and applied loads from wind and snow is important when developing management strategies to reduce the risk of damage from these abiotic agents. Current predictive approaches are generally empirical and based on a posteriori surveys of failures. A more rigorous engineering approach to understanding response phenomenon in trees subjected to extreme winds has been attempted herein. The size of trees and their architecture (shape and structure) greatly influence their mechanical stability under dynamic loading. Considering trees as porous media, wind loads on them are affected by their resistance to …

Tornado Occurrence Modelling And Equivalent Tornado Design Wind Profile For Canada, Qian Huang

Electronic Thesis and Dissertation Repository

The tornadoes can be devastating to structures and infrastructure systems. They can cause fatalities and economic losses. In this thesis, the tornado hazard for Canada is systematically assessed. The use of three spatial point processes (i.e., Poisson, zero-inflated Poisson, and negative binomial models) are first investigated in a hierarchical structure to predict the tornado occurrence rate by considering the annual cloud-to-ground lightning flash density and annual thunderstorm days as covariates. An existing historical tornado catalogue with reported tornado events up to 2009 is considered and the population bias effect in estimating the tornado occurrence rate is included. Both the Bayesian …

Biological Nutrient Removal: Minimizing Carbon And Oxygen Requirements, Masuduz Zaman

Electronic Thesis and Dissertation Repository

With increasing focus on the carbon footprint of wastewater treatment and rapidly emerging paradigm shift towards resource recovery, energy consumption minimization and utilization of readily available organics for biological nutrient removal in municipal wastewater treatment plants is eliciting significant interest. The objective of this PhD work is to investigate non-traditional approach to minimize carbon and energy demand for biological nutrient removal

The feasibility of using thermal alkaline treated municipal wastewater biosolids as an alternative carbon source for biological phosphorus removal was investigated. Two sequencing batch reactors (SBRs) were operated with synthetic volatile fatty acids (acetic acid and propionic acid) and …

Water Supply Capacity Development In The Context Of Global Change, Patrick Breach

Electronic Thesis and Dissertation Repository

The ANEMI model is an integrated assessment model of global change that emphasizes the role of water resources. The model is based on the principles of system dynamics simulation in order to analyze changes in the Earth system using feedback processes. Securing water resources for the future is a key issue of global change, and ties into global systems of population growth, climate change carbon cycle, hydrologic cycle, economy, energy production, land use and pollution generation.

This thesis focusses on the development of global water supplies necessary to keep pace with a growing population and global economy using an integrated …

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 …

Smouldering Combustion Treatment Of Soils And Granular Activated Carbon Contaminated With Per- And Polyfluoroalkyl Substances, Alexandra L. Duchesne

Electronic Thesis and Dissertation Repository

Per- and polyfluoroalkyl substances (PFAS) are emerging contaminants, ubiquitous in the environment, and are challenging to remediate. Self-sustaining Treatment for Active Remediation (STAR) destroys organic contaminants embedded in porous media using smouldering combustion. Self-sustaining smouldering conditions allow the reaction to propagate through the contaminated media without external energy. This study explored STAR as a remediation option for PFAS-impacted granular activated carbon (GAC) and PFAS-contaminated soil. Three smouldering mixtures were used (i) PFAS-spiked GAC and sand, (ii) PFAS-spiked soil and GAC, (iii) PFAS-contaminated field site soil and GAC. Smouldering temperatures were greater than 900˚C, destroying the GAC. Post-treatment PFAS concentrations of …

Effects Of Drinking Water Treatment Processes On Removal Of Algal Matter And Subsequent Water Quality, Ziming Zhao

Electronic Thesis and Dissertation Repository

Seasonal algal blooms in drinking water sources have increased significantly over the recent past as a result of increased temperature and nutrient loading in surface water due to agricultural and surface runoff. More than 95% of algal cells can be removed by coagulation and flocculation processes. However, algal organic matter (AOM) is not removed well during coagulation, thus causes several operational challenges in drinking water treatment. This research was conducted to investigate the effectiveness of coagulation, granular activated carbon adsorption, and filtration processes on AOM removal and to evaluate disinfection by-products formation potential with/without UV irradiation.

Initially, coagulation performance for …

The Influence Of Porous Media Heterogeneity On Smouldering Remediation, Jiahao Wang

Electronic Thesis and Dissertation Repository

Smouldering remediation is a promising technique for destroying organic contaminants in soil. Forced airflow is vital to supporting the smouldering reaction and to propagate it through the contaminated zone. This research focuses on investigating the effects of permeability heterogeneity on smouldering. A series of unique column experiments, combined with numerical model simulations, were conducted. The results suggest that smouldering can successfully propagate through layers in series despite more than a 1000:1 permeability contrast. However, extinction can occur in the finer layer when smouldering propagates through layers in parallel with a permeability ratio above 3:1. Extinction may occur due to insufficient …