Extraction processes employing emulsion liquid membranes (ELMs), water-in-oil emulsions dispersed in aqueous phase, have been shown to be highly efficient in removing a variety of organic and inorganic contaminants from industrial wastewaters. As a result, they have been considered as alternative technologies to other more common separation processes such as pressure-driven membrane processes. Unfortunately, a widespread use of the ELM process has been limited due to the instability of emulsion globules against fluid shear. Breakup of emulsions and subsequent release of the internal receptor phase to the external donor phase would nullify the extraction process. Numerous studies have been, therefore, made in the past to enhance the stability of ELMs. Examples include adding more surfactants into the membrane phase and increasing the membrane viscosity. However, increased stability has been unfortunately accompanied by loss in extraction efficiency and rate in most reported attempts. The primary objective of this research is to apply the ELMs in a unique contacting device, a Taylor-Couette column, which provides a relatively low and uniform fluid shear that helps maintaining the stability of emulsion without compromising the extraction efficiency of a target compound. The ELM used in this study is made of membrane phase converted into non-Newtonian fluid by polymer addition, which provides additional uncommon remedy for the problem. This innovative ELM process was optimized to treat various types of simulated industrial wastewaters containing selected phenolic compounds and heavy metals. Experiments performed in this study suggested that the newly developed ELM process achieved exceptionally high overall removal efficiencies for the removal of these target compounds in relatively short contact time. Mechanistic predictive models were further developed and verified with the experimental data. Combined with the experimental data and novel mathematical predictive models, this study is expected to have a high impact on immediate practices of emulsion liquid membrane technologies in relevant industries.

This study considers airflow simulations to evaluate the impact of different window air-conditioner locations on the thermal comfort in an office room (OR). This thesis compares the air distribution for an office room by using computational fluid dynamics (CFD) modeling to previously studied rooms. The air distribution was modeled on a typical office room window air conditioning unit, air supply from a high pressure on the top and the low pressure exhaust on the bottom considering the existing manufacturing ratios for surface areas. The discharge angle for the supply grill of the AC unit was varied from 20 to 40 degrees. The position of the air conditioner was also varied and studied at 60%, 75% and 90% of the total height of the room. In addition, the location of the occupant within the office room was varied, two locations were studied, one where the occupant is far from the unit and the other to closer to the AC unit at the middle of the room. Predictions of the air movement, room temperature, room relative humidity, comfort level, and distribution of contaminants within the office room are shown. Analysis of these simulations is discussed. Energy estimations are also performed and evaluated. The positions of the air-conditioner unit, the inlet angle and the occupant position in the office room have shown to have an important impact on supply controlling air quality and thermal comfort. Results are in good agreements with the experimental data.The primary function of a HVAC (heating refrigerating and air conditioning) system is the generation and maintenance of comfort for occupants in a conditioned space [1]. This work also provides a detailed analysis of three-dimensional mixed convective flow induced by a window air conditioning system. Using a three dimensional CFD simulation, several characteristics of human comfort are analyzed.

The effect of engineered nanoparticles (ENPs) mixture consisting of silver oxide, (Agg0[Silver Oxide Nanopartical], 20 nm), titanium dioxide, (TiO2[Titanium dioxide], 30-40 nm) and zinc oxide, (ZnO, 20 nm) compared with their bulk metal salts was evaluated against unspiked activated sludge (control) using 3 parallel pilot-scale treatment plants. The total concentration of the ionic species of Ag+ Ti[Silver + Titanium] and Zn(2+) in the effluent of the ENP spiked activated sludge (AS) was below limits of detection and> 99% of the spiked ENP were found in the waste activated sludge (WAS), whereas 39 – 58 % of Ag0[Silver Oxide Nanopartical], 51 – 63 % and 58 – 74 % of ZnO ion concentrations were recovered in the anaerobic digestate (AD) cake suggesting higher affinity of ENPs to WAS than to anaerobic digestate. ENPs induced a 2-fold increase of the microbial community specific oxygen uptake rate (SOUR) compared with the control and > 98 % of ammonia and 80 % of COD were removed from the AS suggesting that the heterotrophic biomass retained their ability to nitrify and degrade organic matter at the spiked ENP concentration. The floc size and cultivable microbial abundance was reduced in the ENP spiked AS with no apparent disruption of the overall AS process efficiency. However, scanning electron microscopic analysis clearly showed damage to specific microbial cells. The lipid fingerprint and 16S rRNA gene-based pyrosequencing evidenced the dominance of Proteobacteria, Firmicutes, and Bacteriodetes with a clear temporal shift in microbial community structure. The prominent nano-tolerant bacterial species identified were Acidovorax, Rhodoferax, and Comamonas whereas Methanocorpusculum and Methanosarcina were recovered in AS and were the dominant Archaea in the AD with 99 and 98 % similarities to the closest culturable relative. Their presence in the AS suggests tolerance to ENPs and oxygen-dependent respiration. V. fisheri activity was not sensitive to the ionic concentrations of the ENP or metal salt mixture in the digestate samples and illustrates the need to develop bioassay using indigenous wastewater microorganisms to detect the potential effect of ENP. Overall, unlike other xenobiotic compounds, ENPs can hasten the natural selection of microbial species in activated sludge and anaerobic digestion processes.

Emerging contaminants (ECs) are chemicals such as pharmaceuticals and personal care products that have been detected in various environmental matrices, including drinking water supplies at trace concentrations (ng/L-ug/L or ng/kg-ug/kg). Current wastewater treatment plant technology is largely ineffective at removing ECs. The objectives of this investigation were to: 1) determine the occurrence of ECs in private well water supplies in Montgomery and Roanoke County, VA 2) quantify the concentrations of three ECs in selected private water supplies; 3) examine the relationship between water quality constituents (nitrate, bacteria, pH and total dissolved solids) to EC occurrence in private water supplies; and 4) determine the ability of the MicroEvapTM, a novel wastewater treatment technology, to remove ECs from secondary wastewater effluent. In partnership with the Virginia Household Water Quality Program, 57 private water supplies were sampled and tested for the occurrence of 142 ECs and 43 other water quality constituents. Up to 73 ECs were detected in the sampled private water supplies. Higher numbers of ECs detected in the tested private water supplies were related with nitrate >1 mg/L, total dissolved solids >250 mg/L, and the presence of total coliform bacteria. Results indicate the MicroEvapTM technology had >99% removal effectiveness for all 26 tested ECs from three secondary wastewater effluent. With the increasing detection of ECs in water bodies, it is essential to understand the occurrence of ECs and environmental predictors of EC presence in different water matrices and continue to develop water treatment technology capable of treating wastewater for EC removal. / Master of Science

This work presents the use of numerical modeling and simulation for the analysis of transport phenomena in engineering systems including zero boil-off (ZBO) cryogenic storage tanks for liquid hydrogen, refrigerated warehouses, and human-occupied air-conditioned spaces. Seven problems of medium large spaces in these fields are presented. Numerical models were developed and used for the simulation of fluid flow and heat and mass transfer for these problems. Governing equations representing the conservation of mass, momentum, and energy were solved numerically resulting in the solution of velocity, pressure, temperature, and species concentration(s). Numerical solutions were presented as 2-D and 3-D plots that provide more insightful understanding of the relevant transport phenomena. Parametric studies on geometric dimensions and/or boundary conditions were carried out. Four designs of ZBO cryogenic liquid hydrogen storage tank were studied for their thermal performance under heat leak from the surroundings. Steady state analyses show that higher flow rate of forced fluid flow yields lower maximum fluid temperature. 3-D simulation provides the visualization of the complex structures of the 3-D distributions of the fluid velocity and temperature. Transient analysis results in the patterns of fluid velocity and temperature for various stages of a proposed cooling cycle and the prediction of its effective operating term. A typical refrigerated warehouse with a set of ceiling type cooling units were modeled and simulated with both 2-D and 3-D models. It was found that if the cooling units are closer to the stacks of stored packages, lower and more uniform temperature distribution can be achieved. The enhancement of thermal comfort in an air-conditioned residential room by using a ceiling fan was studied and quantified to show that thermal comfort at higher temperature can be improved with the use of ceiling fan. A 3-D model was used for an analysis of thermal comfort and contaminant removal in a hospital operating room. It was found that if the wall supply grilles are closer to the center, the system has better performance in both contaminant removal and thermal comfort. A practical guideline for using CFD modeling in indoor spaces with an effective meshing approach is also proposed.

The research described herein is composed of four major areas of practice. It examines the overall performance of runways and provides tools designed to improve current runway operations and management with particular emphasis on contaminated surfaces. Presented in this thesis is an overview of how to design airport pavements in order to achieve optimal friction by specifically focusing on material selection and construction techniques for rigid and flexible pavements. Rubber buildup and the impact rubber accumulation has on decreasing runway friction, particularly in a range of climatic conditions, is discussed. Four commonly used rubber removal techniques are presented and evaluated. Through this research, an analytical hierarchy process (AHP) decision making protocol was developed for incorporation into airport pavement management systems (APMS). Runway surface condition reporting practices used at the Region of Waterloo International Airport are evaluated and recommendations for improving current practices are identified. Runway surface condition reporting can be improved by removing subjectivity, reporting conditions to pilots in real time, standardizing terminology and measurement techniques, and including runway pictures or sketches to identify contaminant locations where possible. Reports should be incorporated and stored in the APMS. Aircraft braking systems and their effects on landing distances under contaminated conditions are discussed. This thesis presents a proposed solution for monitoring and measuring contaminated runway surfaces and identifying the risks associated with aircraft landing through using the Braking Availability Tester (BAT). Also proposed in this thesis is a testing framework for validating the Braking Availability Tester. The proposed BAT measures interaction between aircraft antiskid braking systems and runway contaminants to determine landing distances more accurately. Finally, this thesis includes a discussion explaining how pavement design, contaminant removal, results from friction tests, and results from the BAT can be incorporated into airport pavement management systems. APMS data can be analyzed to economically optimize and prioritize scheduling of pavement maintenance, preservation and rehabilitation treatments to maintain a high level of service, thereby contributing to runway safety and optimization.

The research described herein is composed of four major areas of practice. It examines the overall performance of runways and provides tools designed to improve current runway operations and management with particular emphasis on contaminated surfaces. Presented in this thesis is an overview of how to design airport pavements in order to achieve optimal friction by specifically focusing on material selection and construction techniques for rigid and flexible pavements. Rubber buildup and the impact rubber accumulation has on decreasing runway friction, particularly in a range of climatic conditions, is discussed. Four commonly used rubber removal techniques are presented and evaluated. Through this research, an analytical hierarchy process (AHP) decision making protocol was developed for incorporation into airport pavement management systems (APMS). Runway surface condition reporting practices used at the Region of Waterloo International Airport are evaluated and recommendations for improving current practices are identified. Runway surface condition reporting can be improved by removing subjectivity, reporting conditions to pilots in real time, standardizing terminology and measurement techniques, and including runway pictures or sketches to identify contaminant locations where possible. Reports should be incorporated and stored in the APMS. Aircraft braking systems and their effects on landing distances under contaminated conditions are discussed. This thesis presents a proposed solution for monitoring and measuring contaminated runway surfaces and identifying the risks associated with aircraft landing through using the Braking Availability Tester (BAT). Also proposed in this thesis is a testing framework for validating the Braking Availability Tester. The proposed BAT measures interaction between aircraft antiskid braking systems and runway contaminants to determine landing distances more accurately. Finally, this thesis includes a discussion explaining how pavement design, contaminant removal, results from friction tests, and results from the BAT can be incorporated into airport pavement management systems. APMS data can be analyzed to economically optimize and prioritize scheduling of pavement maintenance, preservation and rehabilitation treatments to maintain a high level of service, thereby contributing to runway safety and optimization.