Master of Science, The Ohio State University, 2023, Civil Engineering

Ozone and ozone followed by biologically active filtration (ozone-BAF) for drinking water treatment can be used to effectively address various contaminants, including two of the largest health-related treatment issues that Ohio public water systems (PWSs) face: chlorination disinfection byproducts (DBPs) and cyanotoxins. The Ohio Environmental Protection Agency (Ohio EPA) uses the Ten State Standards (TSS) (GLUMRB, 2022) for approving detail design plans (“Plan Approval”) of capital improvement projects for PWSs in Ohio. However, ozone is considered an emerging technology in Ohio, defined as a treatment technology without extensive design criteria in the TSS or another Ohio EPA guideline. As a result, emerging technologies, including ozone treatment, often require pilot-scale demonstration for Plan Approval. Pilot-scale demonstration is a barrier for PWSs due to the added cost, time, logistical challenges, and expertise required. These challenges are more substantial for small and medium-sized PWSs than for larger PWSs. Consequently, less appropriate technologies may be installed when a pilot-scale demonstration study is required, leading to lower drinking water quality and/or higher costs for PWSs. To continue innovation for PWSs in Ohio, the Ohio Water Resources Center (Ohio WRC) has partnered with the Ohio EPA to develop design standards for emerging technologies, along with extensive collaboration from various stakeholders, including design engineers, water utility professionals, USEPA representatives, and Ohio AWWA Technology Committee representatives. The first design standard for Low-Pressure Membrane (LPM) filtration (M. E. Patterson et al., 2021) is currently under final Ohio EPA review. Presented in this document is the second design standard - for ozone treatment of oxidizable organics. Ohio EPA plans to also adopt this design standard into Plan Approval policy. The purpose of the design standard is to streamline Plan Approval of ozone design in Ohio (open full item for complete abstract)

Committee: Linda Weavers (Advisor); Timothy Wolfe (Committee Member); Allison MacKay (Committee Member); Natalie Hull (Committee Member) Subjects: Civil Engineering; Environmental Engineering

MS, University of Cincinnati, 2021, Engineering and Applied Science: Environmental Engineering

VOC emissions from industries have increasingly been difficult to treat in the recent years due to the hydrophobicity nature of the compounds utilized in manufacturing and treatment. Although physiochemical, thermo and catalytic oxidation processes have been successfully implemented in treating VOCs, a cost and energy efficient alternative is required. Biofiltration has proven to be an effectual treatment technology in biodegrading hydrophilic and hydrophobic VOCs. However, the degradation of hydrophobic VOCs has been a challenge due to their low gas-liquid phase mass transfer rate. In this thesis, a literature review is presented on the best strategies available to incorporate in a biofiltration system to degrade hydrophobic and recalcitrant VOCs effectively. Employing a biosurfactant in a fungal biocatalyst to increase the solubility and bioavailability of the hydrophobic VOCs have had successful results with high percentage of removal efficiency. For this study, biodegradation of 2-Ethyl-1-Hexanol, a highly hydrophobic VOC emitted from the paint booth of an automobile industry was studied. Increasing concentrations of 2-EH, mimicking that of an industry, were employed in a Biotrickling Filter seeded with filamentous fungi and surfactin. The biofiltration system was supplied with continuous flow of nutrients, maintained at pH 4. The effect of the increasing loading rates on the BTF performance, reaction rate kinetics, COD consumption, nitrogen utilization and carbon mass balance were observed and recorded. The removal efficiency of 2-EH with increasing loading rates ranging from 3.98 g/(m3.hr) to 47.69 g/(m3.hr) were between 95% to 98%, one of the highest recorded percentages for a hydrophobic VOC treatment in published studies.

Committee: George Sorial Ph.D. (Committee Chair); Margaret Kupferle Ph.D. (Committee Member); Drew McAvoy Ph.D. (Committee Member); Bineyam Mezgebe Ph.D. (Committee Member) Subjects: Environmental Engineering

MS, University of Cincinnati, 2020, Engineering and Applied Science: Environmental Engineering

Trihalomethanes (THMs) are a group of volatile organic compounds, used widely in the industries as solvents. The presence of THMs in the environment can cause air, water and soil pollution. The compound constituting THMs are Chloroform (CF), Bromodichloromethane (BDCM), Dibromochloromethane (DBCM), and Bromoform (BF). These compounds are toxic in nature and deemed potential carcinogenic to human. The US Environmental Protection Agency has provided a strict maximum contaminant level (MCL) for THMs in water. In air and soil pollution, the hazard level is set at different values for the four constituents. To reduce air pollution due to THMs emission, physical as well as chemical methods can be adapted. Among, the available technologies, it is essential to find a method that is effective, easy to operate, cost effective and eco-friendly. The use of aerobic biotrickling filter (BTF) with filamentous fungi as biodegrading organism, had proven to have significant impact on removal of CF in the presence of cometabolites from the gaseous phase. The current research study evaluates the significance of an aerobic BTF in bioremediation of a ternary mixture of the three compounds of the THMs group, CF, BDCM and DBCM. A state-of-art BTF was set up for the study, which was seeded with filamentous fungal consortium and biosurfactant, at the beginning of the study. The biosurfactant was synthesized from Bacillus subtilis and their attribute to accumulate at the interface of air and water due to their amphiphilic molecular structure was utilized to ensure the microbial growth in the system. The biosurfactant also enhanced the interaction between the volatile THMs mixture and biofilm surface. A pH 4 nutrient solution containing the essential growth vitamins and minerals required for the biomass was supplied to the system at a constant rate of 2 liter/day. The system was kept under acidic condition to ensure the growth of fungi colonies. A gas stream containing the ternary mixture wa (open full item for complete abstract)

Committee: George Sorial Ph.D. (Committee Chair); Margaret Kupferle Ph.D. (Committee Member); Drew McAvoy Ph.D. (Committee Member); Bineyam Mezgebe Ph.D. (Committee Member) Subjects: Environmental Engineering

MS, University of Cincinnati, 2019, Engineering and Applied Science: Environmental Engineering

Traditionally, volatile organic compounds (VOCs) are treated by physicochemical processes such as adsorption by activated carbon, oxidation by a thermal internal combustion engine, and catalytic oxidation. Such mechanisms have successfully reported very high removal efficiencies, but cost efficiency is at stagnation levels, carbon foot-prints are in increasing rates, and energy consumption is elevating due to the excessive off-gases emissions. Environmental biotechnologies represent cost-efficient and environmental friendly processes for air pollution control. However, several challenges face biological treatment processes such as variability of flow rate, composition of contaminants in waste streams, and the long-term operation stability. Since industry looks to develop cost-effective and eco-friendly processes to comply with the 1990 Amendments of the Clean Air Act, biological systems are becoming more suitable in eliminating biodegradable VOCs. Biological systems are also suitable for treating large volumes of gaseous waste streams that contain low concentrations of biodegradable contaminants. It is also worthwhile noting that several developments have been applied to the conventional biofiltration process to adapt more widely with the various composition of VOCs such as recalcitrant chemicals often found in several off-gases emissions. The objective of this study is focused on enhancing the bioavailability and eventually biodegradation of a very hydrophobic compound in a fungi-cultured trickle bed air biofilter (TBAB) by applying a number of operational techniques, starvation, and investigating the concept of introducing bio-additives (cell-filtrate) as a means for allowing consistency of biomass along the length of the biofilter. Emphasis is being placed on the impact of biosurfactants which are known to enhance the solubility of recalcitrant compounds to biological treatment. Two VOCs (2-ethylhexanol (2-EH), a hydrophobic VOC and methoxy-2-propanol (M2P), (open full item for complete abstract)

Committee: George Sorial Ph.D. (Committee Chair); Margaret Kupferle Ph.D. (Committee Member); Drew McAvoy Ph.D. (Committee Member) Subjects: Environmental Engineering

PhD, University of Cincinnati, 2017, Engineering and Applied Science: Environmental Engineering

Disinfection by products (DBPs) resulted from the reactions between the chlorine and natural organic substances which increased the formation of trihalomethanes (THMs). DBPs are carcinogens or have been known to cause health risks. Chloroform (CF) is the most abundant of all THMs with a maximum contaminant level (MCL) of 0.070 mg/L. In addition, CF and other THMs could also originate from sources other than by-products of water disinfection. Several physical and chemical removal methods are used to treat chloroform, which are expensive and could generate secondary pollutants. Biofiltration is one of the most proven technologies for volatile organic compound (VOC) control as it is environment–friendly, cost effective and releases fewer byproducts. In this study, an integrated technology was proposed. The integrated technology consists of nitrogen or air stripping followed by anaerobic or aerobic bio-trickling Filter (BTF). This study evaluated first CF only and secondly mixtures of THMs (CF and dichlorobromomethane (DCBM)). A co metabolite (ethanol) and surfactant (Tomadol 25 – 7) have been used to improve the biodegradation process. In addition, surfactin a bio surfactant was seeded within the BTF and its effectiveness has been investigated. Finally, microbial analysis was conducted to determine the dominant and responsible microbes for the BTFs performance.

Committee: George Sorial Ph.D. (Committee Chair); Ashraf Aly Hassan Ph.D. (Committee Member); Margaret Kupferle Ph.D. P.E. (Committee Member); E Sahle-Demessie Ph.D. (Committee Member); David Wendell Ph.D. (Committee Member) Subjects: Environmental Engineering

PhD, University of Cincinnati, 2013, Engineering and Applied Science: Environmental Engineering

Biofiltration systems demonstrated to very effective in removal of volatile organic compounds (VOCs) from air operating under dynamic loading rates and stressed conditions. More interestingly, Trickle Bed Air Biofilters (TBABs) offer more optimal and controllable operations which result in low maintenance costs over traditional biofilters. Furthermore, due to their higher removal efficiency, consistent performance, and harmless by-products generated they became an attractive option for controlling VOCs emissions from various industrial processes. Yet, biofiltration systems face a number of challenges to compete new proposed techniques such as two-phase bioreactors and oil emended biofilters. Characteristically, hydrophobic compounds, with higher Henry's law constant, present a great challenge for these systems as they are not soluble in water. Limited bioavailability of these VOCs could trigger mass transfer to be rate limiting from gas to liquid phase and hence negatively affecting biofilters performances. Moreover, as biofilters are biologically dependent systems, the exact characterization of the microbial community structures within the active biomass need to be developed in order to get deep insight of the species involved to make the biofiltration technique more efficient, reliable, and oriented either to specific VOCs as well as to be flexible in handling a variety of VOCs. Most importantly, air emissions are always mixture of different type of gases rather than a sole VOC. Hence, inhibitory effect among VOCs could hinder the widespread application of these systems in facilities where off gases are a combination of hydrophilic and hydrophobic VOCs. Finally, variability in waste gases flow and fluctuations in their concentrations limit the treatment efficiency of the biofiltration systems. In this regard, the current study investigated several techniques to effectively biodegrade hydrophobic contaminants. Responding to this aim, the solutions presented (open full item for complete abstract)

Committee: George Sorial Ph.D. (Committee Chair); Ashraf Aly Hassan Ph.D. (Committee Member); E Sahle-Demessie Ph.D. (Committee Member); Makram Suidan Ph.D. (Committee Member); David Wendell Ph.D. (Committee Member) Subjects: Environmental Engineering

Master of Science in Environmental Science, Youngstown State University, 2008, Department of Geological and Environmental Sciences

Biofiltration units (e.g. bioswales and rain gardens) are depressed landscape areas that are designed to receive and filter stormwater runoff. They are applicable in residential and commercial environments with grass, shrubs and perennials plants. The top soils are usually covered with shredded hardwood bark and mulch. The benefits of biofiltration applications include decreased surface runoff, increased groundwater recharge, and pollutant treatment through a variety of processes.The use of the biofiltration as a BMP (Best Management Practices) for treating stormwater runoff has been advocated for in many parts of the world. However, results from many installed units show that biofiltration application for water quality improvements has not always been positive due to inappropriate design and poor maintenance. This is evident in the limited and inconsistency in available data for biofiltration application performance from different studies. It is against this background that this study was undertaken to evaluate the performance of the rain garden and the bioswales (biofiltration swales) constructed on the campus of Youngstown State University to treat stormwater runoff from a parking facility. Stormwater samples were taken from biofiltration inlets, outlets and along the biofiltration units after rain events over a period of ten months. Samples were analyzed for a variety of water quality parameters including nutrients (ammonia-nitrogen, total phosphorus and nitrate-nitrogen), metals, oil and grease, conductivity as well as pH. Parameters were analyzed according to the American Standard Methods. Laboratory results were then analyzed using SPSS statistical software (repeated measures) to compare concentration changes along the biofiltration units. Results from the study indicated that the biofiltration units on Youngstown State University campus is efficient in removing 81.3% total suspended solids (TSS) , 39.1% total phosphorus (TP), 58.1% ammonia (NH3-N), 7.4% red (open full item for complete abstract)

Committee: Felicia P. Armstrong PhD (Advisor); Alan Jacobs PhD (Committee Member); Scott Martin PhD (Committee Member); Larry P. Gurlea (Committee Member) Subjects: Civil Engineering; Earth; Environmental Engineering; Environmental Science; Freshwater Ecology; Landscaping

PhD, University of Cincinnati, 2010, Engineering and Applied Science: Environmental Engineering

Biological treatment represents low-cost and environmental friendly option for air pollution as compared to incineration, catalytic oxidation and adsorption. It has several advantages like minimal power consumption, few byproducts and cost effectiveness. However, several challenges face biological treatment processes such as variability of flow rate and composition of contaminants in waste streams. Furthermore, hydrophobic compounds are not readily available for the microorganisms, creating a deficiency for the use of biological treatment in the industry. Biofiltration for VOCs control is best operated at steady loads of hydrophilic VOCs. In practice the existence of hydrophobic compounds in waste streams is inevitable. In addition, variations in contaminant loads are common in real applications. The objectives of this study are to introduce biological treatment as an effective technique for non-methane hydrocarbon removal from air under stressed operating conditions. Emphasis is being placed on hydrophobic compounds which are known to be recalcitrant to biological treatment. Two hydrophobic compounds; n-hexane and benzene, which are carcinogenic and toxic, were utilized as model compounds. Both compounds were studied separately under different operating conditions. Loading rates up to 48 and 77 g/(m3 h) for n-hexane and benzene were applied at the inlet prividing elimination capacities of 39 and 61 g/(m3 h) , respectively. These elevated elimination capacities have not been achieved by any reported research for hydrophobic compounds at practical removal efficiencies as obtained in this study (minimum 78%). Surfactants were introduced in the biofiltration system as means for enhancing solubility. The effect of two different surfactants; Triton X-100 and Tomadol 25-7, were investigated at different loading rates for the biodegradation of n-hexane operating under neutral pH. Other means of increasing the bioavailability of hydrophobic compounds was the introduction o (open full item for complete abstract)

Committee: George Sorial PhD (Committee Chair); Margaret Kupferle PhD, PE (Committee Member); Paul Bishop PhD (Committee Member); E Sahle-Demissie PHD (Committee Member) Subjects: Environmental Engineering

PhD, University of Cincinnati, 2007, Engineering : Environmental Engineering

Fluctuations in influent concentrations and variations in waste air composition challenge the application of biofiltration technology in the chemical industry. An integrated system of a cyclic 2-bed adsorption/desorption unit and a trickle bed air biofilter (TBAB) is proposed and applied in this study. The primary goal of the study was to maintain long-term, stable consistent high performance of volatile organic compounds (VOCs) degradation in the TBAB. Five specific studies were conducted to accomplish the primary objective. Investigations were conducted on independent TBABs under single VOC interchange with periodic backwashing as biomass control. The VOCs considered were common solvents used in paint booth industries. Two aromatic compounds (styrene and toluene) and two aliphatic compounds (Methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK)) were studied. This study simulated VOC emission rotation as the process of production rotated in certain chemical industries. Experimental findings indicated that the biofilter required apparent re-acclimation period when the VOC was interchanged to aromatic ones. The second phase investigated two mixtures of these VOCs in two independent parallel trains of TBAB under step change in influent concentration. Critical loadings were determined under backwashing and starvation operating strategies. In the third phase, the buffering capacity of a cyclic 2-bed adsorption unit under a square wave of fluctuating condition was evaluated for a feeding composition based on EPA industrial emission report. The cyclic 2-bed adsorption unit succeeded in attenuating load fluctuations as compared to non-cyclic operations. Furthermore, the time to breakthrough of contaminants encountered in non-cyclic operations could lead to a starvation period to the followed biofilter and eventually long period of acclimation after breakthrough of VOCs from the adsorber. In the fourth phase, the integrated system of 2 cyclic adsorption/desorption be (open full item for complete abstract)

Committee: Dr. George Sorial (Advisor) Subjects: Engineering, Environmental

PhD, University of Cincinnati, 2006, Engineering : Environmental Engineering

Biofiltration for VOC control is best operated at steady loads of contaminants. Variations in contaminant loads are, however, common in real application. As a solution to this limitation in biofiltration system, an innovative integrated technology was proposed to achieve stable contaminant removal efficiency by combining the buffering capacity of a 2-bed cyclic adsorption/desorption unit with a Trickle Bed Air Biofilter (TBAB). The overall goal of the study was accomplished through three specific studies: Characterization of TBAB performance; Development of adsorption process; Application of an integrated technology. First, investigations were made to operate independent lab-scale TBAB systems to remove single VOC. Experimental findings supported the handling limitation of biofilter performance under adverse feeding conditions experienced after biofilter reactor startup, biofilter backwashing as biomass control, fluctuating loads, or non-use periods (starvation and stagnant). Second, the design of the adsorption system was fundamentally based on the results obtained from the adsorption isotherm, which were explored by using Tedlar gas sampling bags as a simple constant volume method. The adsorption system consisted of two fixed beds which are alternately pressurized and depressurized in a 2-step cycle, where adsorption and desorption was simply achieved. Its main function is to dampen VOC concentration pulses in waste streams. Finally, by utilizing an adsorption/desorption cycle in a 2-fixed bed adsorption, an integrated treatment process of the 2-bed adsorption unit followed by the TBAB was developed and extensively tested. It was proven to achieve the goal of reliably treating fluctuating VOC loading with high removal efficiency; and attain more consistent emission compliance and economical design of biofiltration facilities.

Committee: Dr. George Sorial (Advisor) Subjects: Engineering, Environmental

PhD, University of Cincinnati, 2004, Engineering : Environmental Engineering

Biofiltration has developed into a promising technology for the abatement of volatile organic compounds (VOCs), odors, and hazardous air pollutants in waste gas streams. Many factors, however, are still creating an environment for greater innovation as well as new products for biofiltration processes. Rotating drum biofilters (RDBs) are such an innovation. The objectives of this investigation are to develop and understand RDBs and consequently to design and operate RDBs properly. Three RDBs, a single-layer RDB, a multi-layer RDB, and a hybrid RDB, were developed and evaluated at various design and operation conditions in this investigation. Spongy medium that was used to support the biofilms was mounted on a cylindrical drum frame that was rotated at a preset speed. Diethyl ether, toluene, and hexane were chosen as the model VOC. Results showed that the RDBs were readily started up and removed VOCs with high water solubility and a low value of Henry' constant efficiently with more than 6 month duration without any biomass control measures. The single-layer and hybrid RDBs usually reach the lowest and highest VOC removal efficiency. VOC removal efficiency decreased with increased VOC loading rate and decreased gas empty contact time (EBCT). Nitrate in the liquid phase of the RDBs can be rate-limiting for diethyl ether removal. With increased drum rotating speed, the change in VOC removal efficiency depends on VOC properties, VOC loading rate, drum rotating speed value, and biofilter configurations. The microbial community structure along medium depth are almost identical for each of the RDBs , however, the structure changes with the operation conditions and biofilter configuration. Review of the biomass accumulation rates among different layers reveals four biomass accumulation patterns which represent different removal mechanisms: surface biofiltration, in-depth biofiltration, shallow biofiltration, and reverse biofiltration. The dominant biomass accumulation patter (open full item for complete abstract)

Committee: Dr. Makram Suidan (Advisor) Subjects: Engineering, Environmental

PhD, University of Cincinnati, 1999, Engineering : Environmental Engineering

Increasing regulatory pressure for VOC emissions reduction has accelerated the development of more cost effective VOC air pollution control (APC) technologies. Biofiltration is a viable technology to fill this role, for the purification of air streams polluted with biodegradable VOCs. In the biofilter, these pollutants diffuse from the air stream into a stationary mass of moist biological film, where they are oxidized by enzymatic catalysis at ambient pressures and temperatures. Properly operated, this natural, biological mineralization process will produce only benign by-products, such as inorganic salts, carbon dioxide, and water, with some additional biomass. Although research into the science and development of the technology of biofiltration has been performed for over fifteen years, biofiltration remains not widely accepted as a proven technology for VOC APC. This perception is especially true for applications treating high influent VOC concentrations and requiring high VOC removal efficiencies. This research was undertaken to develop a new, cost effective biofiltration technology which can reliably treat air streams polluted with high VOC concentrations and achieve very high removal (elimination) efficiencies. Investigations were made to evaluate different biological attachment media, in order to identify the medium most suited to such an application. Using this medium, a reliable biofiltration technology was developed and extensively tested, which can achieve the goal of reliably treating high concentrations of VOCs at high loadings with high removal efficiency. Techniques for the management and control of the accumulating by-product biomass were developed. Procedures are presented for the calculation of VOC solubility and biological kinetic parameters, at the biofiltration operating temperature. A procedure for estimating the upper limit for biofiltration for the influent air VOC concentrations is presented. A simple, explicit biofilter design equation was (open full item for complete abstract)

Committee: Makram Suidan (Advisor) Subjects:

PhD, University of Cincinnati, 2002, Engineering : Chemical Engineering

Major technical challenges confronting biofiltration technology are: effective support media for biotrickling filters, understanding of biofiltration of mixed contaminants, biofiltration of contaminants at very low concentration, and biofilm model calculation for concentration distribution within a biofilm. In this research work, a composite media was designed and tested in bench scale biotrickling filters. The media were made of a polymeric support media coated with either activated carbon or sand. The resulted media will inherit properties such as high void fraction, high interfacial area, and low bulk density from the original packing, plus enhanced surface suitable for biofilm attachment and growth. The new media were evaluated along with the original media in bench scale biotrickling filters. A fibrous packing medium was evaluated in the biofiltration of ethanol in biotrickling filters and microbiofilters. The microbiofilter system, operating according to a new experimental protocol, can be used to determine both reaction rate constants and mass transfer coefficient with the help of a concise mathematical model. The identified parameters are then used to calculate concentration profiles inside a biotrickling filter and to predict its biofiltration performance. This fibrous packing medium was later used in a pilot scale biotrickling filter test to treat ethanol emission found in exhaust gases from baking ovens. The same fibrous media as well as the experimental protocol were also used in studying mixed contaminants biofiltration. Biofiltration of mixed contaminants was studied using target compounds of alcohols, acetone, acetaldehyde in biotrickling filters and microbiofilters using the fibrous medium. In a batch system, the preference of individual contaminant by the biomass can be carefully examined. Meanwhile, their respective biodegradation kinetics can be investigated by employing a mathematical model, which was also developed to portray the biofiltration p (open full item for complete abstract)

Committee: Dr. Rakesh Govind (Advisor) Subjects:

MS, University of Cincinnati, 2001, Engineering : Environmental Engineering

The United States Environmental Protection Agency does not regulate the air emissions of volatile compounds from municipal waste treatment plants as of this writing. There have been proposals for changes in this requirement. California has already enacted legislation to limit the emissions from wastewater treatment plants, and many municipalities recognize that the regulations to limit these emissions are inevitable. In order to be prepared for new regulations, The Metropolitan Sewer District of Greater Cincinnati has taken a proactive approach to limiting their volatile emissions. This approach will make it easier to comply with the proposed regulations. The purpose of this research project was to determine the emission of volatile organic compounds (VOC's) and other hazardous materials from a biofilter operating at a representative municipal wastewater treatment plant. The research involved the monitoring of a biofilter that controls the gas emissions from a sludge holding tank. A correlation was developed between an operating biofilter and the physical and biological properties of the biofilter. The study was performed at the Polk Run Wastewater Treatment Plant. This plant treats primarily residential sewage. The average daily flow is 3.5 million gallons. This plant serves the residential community of Loveland, Ohio and the surrounding suburban area. This study confirmed that a biofilter is an effective method for controlling odors and emission of volatile compounds from a sludge holding tank at a municipal wastewater treatment plant. The main gaseous emission identified and the source of the predominant odors was determined to be hydrogen sulfide gas. The bacteria and fungi found in the biofilter controlled this odor by reducing the concentration of hydrogen sulfide gas. The bacteria found in the biofilter were identified as Pseudomonas aeruginosa and Salmonella. These bacteria are commonly found in wastewater. The wood bark in the biofilter provided the medium (open full item for complete abstract)

Committee: Dr. Paul Bishop (Advisor) Subjects: Engineering, Environmental