Engineering Commons^™

Treatment Of Combined Sewer Overflows Using Ferrate (Vi), Rohan Gandhi

Electronic Thesis and Dissertation Repository

Prevention of pollution from combined sewer overflows (CSOs) is currently a major concern due to their impact on aquatic and human environment. With the stringent regulations related to the CSOs treatment, it is necessary to develop an efficient, fast and low cost treatment technique that meets the applicable criteria. In this work, the comprehensive study was done to determine the efficiency of ferrate (VI) for the treatment of CSOs. At a Fe (VI) dose of 0.24 mg/l, TCOD, SCOD, TBOD₅, SBOD₅, TSS, VSS, TP, TN and soluble TN removal efficiencies of 71%, 75%, 69%, 68%, 72%, …

Hydrogeological And Thermal Sustainability Of Geothermal Borehole Heat Exchangers, S. Emad Dehkordi

Electronic Thesis and Dissertation Repository

Assessment of the current approach taken by guidelines and design methods of vertical closed loop heat exchangers shows that often groundwater flow is either disregarded or is not methodically incorporated. The state of scientific research in this arena reveals that overlooking the groundwater flow in the design procedure may not always be a correct assumption. The significance of advective heat transport compared to conduction is defined by the groundwater flux or Darcy velocity which heavily depends on the hydraulic conductivity of the ground, followed by the hydraulic gradient which has a relatively limited range. A sensitivity analysis on ground and …

Optimisation Of The Transesterification Stage Of Biodiesel Production Using Statistical Methods, Arnold Paintsil

Electronic Thesis and Dissertation Repository

The present research examines solely the transesterification stage of the biodiesel production process. Six process variables that affect the yield of biodiesel at this stage are examined using the 12 run Plackett-Burman Design. To study the effect of FFA[1] and to replicate real life situations where oil (feedstock) contain varying amounts of FFA, linoleic acid is used as FFA and intentionally added to high oleic acid canola oil containing less than 0.07% FFA. The process is catalyzed with potassium carbonate and evaluated at varying temperatures, stirring rates, reaction times and methanol oil ratios. The yields at the end of …

Carbon-Nzvi Nanocomposites For Dechlorination Of Halogenated Hydrocarbons, Jing Cheng

Electronic Thesis and Dissertation Repository

A family of hybrid nanocarbon/nanoiron composites has been developed with the aim to carry out simultaneous adsorption and dechlorination of chlorinated hydrocarbons from aqueous solutions. Several methodologies for the synthesis of these materials are evaluated in terms of their adsorption capacities and dechlorination activities. Detailed spectroscopic and microscopy studies indicate that the adsorption ability of the carbonaceous support is greatly improved after acid oxidization, attributed to the formation of oxygenated functional groups on their surfaces. When iron nanoparticles are incorporated on the composites, the materials show a much higher trichloroethylene (TCE) removal efficiency compared to bare metallic nanoiron particles or …

Ignition Method Development And First Field Demonstration Of In Situ Smouldering Remediation, Grant C. Scholes

Electronic Thesis and Dissertation Repository

Self-sustaining Treatment for Active Remediation (STAR), a smouldering combustion-based technology for remediating sites contaminated by industrial liquids, has been extensively studied in the laboratory. The technology had not been demonstrated at a real site. Moreover, the ignition method (based on heat conduction) for the process used in the laboratory was not appropriate for field deployment and an alternative was required. This work first presents the development of a new ignition method for smouldering combustion. This ignition technique (based on heat convection) was proven effective via laboratory tests, and then applied and improved through two field tests. These field tests, conducted …

Study Of Vertical Dense Jet Dilution In A Marine Environment, Nadeem Ahmad

Electronic Thesis and Dissertation Repository

Brine is a byproduct of many industrial and mining processes, including desalination. Brine is commonly conveyed in long pipe lines and disposed in the bottom of the sea through multiport diffusers, forming dense jets, also known as fountains. An acceptable level of brine concentration is required to be achieved at the boundary of a regulatory mixing zone surrounding a point of discharge. Such mixing zones are allocated with the objective of limiting environmental deterioration within their boundaries. Mixing zones are, nevertheless, not allowed when discharging brine in sensitive areas and when brine is toxic.

The main contribution of this study …

Numerical Evaluation Of Community-Scale Aquifer Storage, Transfer And Recovery Technology, Jessica Barker

Electronic Thesis and Dissertation Repository

Communities in the coastal regions of south-western Bangladesh currently experience severe seasonal water scarcity and groundwater sources of unsuitable salinity. Aquifer storage, transfer and recovery (ASTR), using a seasonal surplus of potable water, is being tested as a potential low-cost (less than $8000 USD) water supply alternative for these communities. A variable-density numerical groundwater model was developed to investigate the engineering technical feasibility of small-scale ASTR systems for the coastal communities in Bangladesh and specifically to support future field site selection and system design. The numerical model was calibrated based on an existing ASTR site and applied to explore the …

Upgrading Pyrolysis Oil To Produce Liquid Transportation Fuels, Ehsan Reyhanitash

Electronic Thesis and Dissertation Repository

The effects of stabilizing fast pyrolysis oil via catalytic alcohol pretreatment on upgrading via hydrodeoxygenation or thermal treatment was studied by comparing the properties of upgraded-stabilized oils with those of upgraded-non-stabilized oils (benchmarks). The major expected effect was reduction in molar mass of upgraded oils, as stabilization was expected to reduce the reactivity of fast pyrolysis oil, thereby reducing polymerization. It was observed that molar mass reduction was induced by dilution effect of the alcohol rather than reactivity reduction due to stabilization. Also, the effects of different alcohols on stabilization and subsequent upgrading were examined at minimized dilution effect conditions. …

Treatment Of Aqueous Biomass And Waste Via Supercritical Water Gasification For The Production Of Ch4 And H2, Izad Behnia

Electronic Thesis and Dissertation Repository

The present study targets to convert aqueous fraction of fast pyrolysis oil into methane and hydrogen gases via supercritical water gasification (SCWG). Water above its critical point is referred to as supercritical water, which has unique properties such as a loss of hydrogen bonding, becoming an excellent solvent for organic compounds. In this thesis, SCWG was used to gasify slurry materials into high calorific gases including CH₄ and H₂. Production selectivity towards more methane or hydrogen was affectively controlled by operational conditions. However, in the absence of catalyst (bank test), gas formation was very minimal. SCWG of …

Fate Of Estrogens In Anaerobic Digestion And Their Removal In Advanced Oxidation, Shubhajit Sarkar

Electronic Thesis and Dissertation Repository

Estrogenic compounds are most significant endocrine disrupting compounds (EDC), which are of primary concern due to their widespread presence in the aqueous environment and also due to their adverse impact both on aquatic life and potential risk to human health. Conventional wastewater treatment plants are not designed to remove EDC, with biosorption on biosolids as the predominant removal mechanism. Anaerobic digestion is one of the most preferred processes employed for sludge stabilization in wastewater treatment plants. Advanced oxidation processes (AOPs) are seen as promising technologies for removal of estrogens from the environment. In this research, a controlled degradation study of …

Application Of Mixed Iron Oxides In Subsurface Remediation Technologies, Saidur Rahman Chowdhury

Electronic Thesis and Dissertation Repository

Heavy metal contamination of soil and groundwater has been a concern in water supply and public health in many countries where the water supply system draws primarily from groundwater. In the present study, mixed maghemite-magnetite nanoparticles have been used as adsorbents for Cr(VI), As and Cd(II) removal. From the study, it is apparent that the removal of Cr(VI ), Cd(II) and As(V) by mixed iron oxide nanoparticles depends on pH, temperature, contact time, solid/liquid ratio and initial concentration of heavy metals. The results showed that Cr(VI) adsorption on mixed maghemite-magnetite was dependent on solution pH between 3 and 6. Theoretical …

Effect Of Groundwater-Lake Interactions On The Distribution Of Arsenic In A Freshwater Beach, Jacky Sk Lee

Electronic Thesis and Dissertation Repository

This thesis presents field measurements and numerical modeling that provide insight into the nearshore geochemical conditions and groundwater flows controlling the mobility of arsenic (As) in a freshwater beach aquifer and its potential discharge to Lake Erie. Field measurements were performed via shore-normal monitoring transects installed at beaches (Little Beach and Main Beach) located adjacent to a brownfield industrial harbour site that has elevated sediment and groundwater As concentrations. Detailed pore water chemistry analyses revealed elevated As (up to 0.056 mg/L) 1 - 2 m below the shoreline at all transect locations. The distributions of species in the aqueous and …

Biofilm Control In A Fludized Bed Bioreactor (Fbbr) Treating Municipal Wastewater: Optimization, Modeling, And Nitrous Oxide (N2o) Emissions, Ahmed Eldyasti

Electronic Thesis and Dissertation Repository

Among the various biological wastewater treatment processes for industrial and municipal wastewater treatment, fluidized bed bioreactors (FBBR) demonstrate numerous advantages compared to suspended growth systems such as lower hydraulic retention time, high surface area and accordingly high biomass retention time, higher volumetric conversion rates, lower sensitivity to temperature, and less sludge production. Despite the numerous biofilm bioreactor configurations and system schemes that are currently available for a wide variety of environmental applications, the development and optimization of a stable biofilm that is capable of offering effective and integrated functions, i.e. biodegradation, biomass-liquid separation, and biomass retention along with a substantial …

Simulation Of Mobility And Retention Of Selected Engineered Nanoparticles Beneath Landfills, Shumsun N. Siddique

Electronic Thesis and Dissertation Repository

Engineered Nanoparticles (ENPs) have generated significant public and scientific excitement due to their unique physical, chemical, and electrical properties which has led to their application in a wide variety of industries. Landfills are a likely disposal site for ENPs at the end of their useful life, either encapsulated in a product as discrete nanoparticles or in nanoparticle agglomerates. Most countries and jurisdictions have landfill design regulations to provide an effective impermeable barrier between a landfill and soil/groundwater, however, landfills are still of concern due to the potential threat to groundwater resources. This study assesses the fate of selected ENPs (multi-walled …

Smouldering Combustion For Soil Remediation: Two-Dimensional Experiments And Modelling, Tanzeer Hasan

Electronic Thesis and Dissertation Repository

Sustaining Treatment for Active Remediation (STAR) is a novel technology for the remediation of soils contaminated with Non-Aqueous Phase liquids (NAPLs). STAR is based upon the concept of liquid smouldering, in which NAPLs embedded in a porous medium are progressively destroyed via an exothermic oxidation reaction which propagates in a self-sustaining manner through the contaminated material. The In Situ Smouldering Model (ISSM), developed to simulate the propagation of STAR as a function of NAPL content and local air velocity, was calibrated for a suite of one-dimensional experiments (MacPhee et al., 2010). However, STAR application at field sites involves propagation of …

Change In Pore Size Distribution Of Compacted Soil Layers And Its Effect On Solute Breakthrough Curves, Sara Karimi

Electronic Thesis and Dissertation Repository

It is often useful to predict contaminant migration from waste containment systems, such as landfills, as part of the assessment of the overall impact of such systems on the receptor environment. In many instances, material properties, for example, those of the liner, are assumed to be constant. This study was conducted to evaluate the accuracy of considering constant material and transport parameters in the modelling of sodium and chloride breakthrough curves through a compacted soil layer using the commercial software, Pollute v.7. Experiments were conducted with three different mixtures of glass beads and varying amounts of kaolinite (30, 40 and …