Master of Science / Department of Civil Engineering / Alok Bhandari / Antibiotics and pharmaceuticals are used to improve the quality of life worldwide. However, incomplete metabolism in humans has resulted in the release of large amounts of pharmaceutical drugs into municipal wastewater treatment plant. Past research has shown the release of antibiotic resistant organisms through wastewater effluents into streams and several studies have reported the occurrence of antibiotic resistant bacteria in major U.S. Rivers. Antibiotic resistant bacteria evolve and are selected by long-term environmental exposure to the low concentrations of antibiotics at the ng /L to g/L range. Infections caused by antibiotic resistant organisms are difficult to treat. The aim of this study was to analyze antibiotic resistance patterns in selected wastewater bacteria that include fecal coliforms, Escherichia coli and enterococci. Microorganisms in municipal wastewater treatment plant influent, secondary clarifier effluent and disinfected effluent were plated in the presence of predetermined concentrations of selected antibiotics. These antibiotics included ciprofloxacin, sulfamethoxazole/ trimethoprim and vancomycin. The diversity of enterococci was further investigated with PCR analysis. Fecal coliforms, E. coli and enterococci were found to be resistant or highly resistant to one or more target antibiotics in the influent and secondary clarifier (SC) effluent. Biological treatment reduced the number of overall and resistant bacteria in the SC effluent sample. UV disinfection was generally very effective and eliminated all fecal indicator organisms.

Master of Science / Department of Biological & Agricultural Engineering / Philip L. Barnes / Water quality in the United States needs to be improved. Currently, 42% (39% of rivers and streams, 45% of lakes and reservoirs) of monitored surface water is considered impaired, indicating that it is no longer suitable for its designated uses such as drinking, recreation, habitat, food supply, agriculture, and ground water recharge (USEPA, 2000, Carpenter et al., 1998). Nonpoint source pollution can be associated with animal manure. This project focuses on two sources of nonpoint source pollution. The first source is runoff from soils that have been enriched in nutrients (nitrogen and phosphorus) by manure application. This project evaluates how effective Alfalfa is at removal of nitrogen and phosphorus from nutrient enriched soils. It also evaluates the use of USDA’s Plant Nutrient model in association with nutrient management plans to prevent enrichment of soils. It was determined that Alfalfa is effective in reduction of nitrogen in soils; however, it was not feasible as a stand alone practice to remediate phosphorus. The use of USDA’s Plant Nutrient model indicated that Corn for silage is the most effective crop for reduction of soil phosphorus while alfalfa and the yields produced in 2004 was the most effective in reduction nitrogen. However, the model tends to underestimate soil nutrient uptake, so it is important to have soil tests conducted periodically to prevent nutrient deficiencies. The second source of nonpoint pollution discussed is runoff from animal feeding operations. This paper evaluates the effects of grass filter strips in prevention of pollution transport off of animal feeding operations. It was determined that filter strips with a ratio of runoff area to filter area of 1:2 is the minimum ratio to effectively prevent nonpoint source pollution.

Doctor of Philosophy / Department of Biological & Agricultural Engineering / Kyle R. Mankin / The overall goal of this study was to evaluate and apply the Soil and Water Assessment Tool (SWAT) model for fecal bacteria modeling. Methods were developed to characterize fecal coliform bacteria (FCB) from livestock, human, and wildlife sources to use as input in the model. Model sensitivity to predict FCB concentration was evaluated for the model parameters and input parameters using both SWAT 2000 and 2005 versions. Sensitivity of input parameters generally, ranked as Bacteria concentration ≥ TBACT > Wildlife source loads > Livestock stocking rate ≥ Livestock manure production rate > BACTKDQ for SWAT 2000 whereas it was ranked as BACTKDQ > TBACT > Bacteria concentration > WDLPQ > WDLPS for SWAT 2005. Sensitivity of model and input parameters were found changed from SWAT 2000. The SWAT (2005) model was calibrated and validated for daily flow, sediment, and fecal bacteria concentration using one year of measured data (January to December, 2004). The SWAT model predicted results with poor to very good agreement when compared with measured data with coefficient of determination (R2) and Nash-Sutcliffe Efficiency Index (E) range of 0.10 to 0.89 for daily flows, sediment, total phosphorus, total nitrogen and total FCB concentration. More extensive in-stream data are needed for more comprehensive model assessment. The SWAT model (2005) was evaluated for source-specific FCB modeling using three years (2004-2006) of observed modified deterministic probability of bacteria source tracking (BST) data. The FCB sources were modeled with three combinations (livestock and human, livestock and wildlife, wildlife and human) and each single source to evaluate the source-specific FCB concentrations. The SWAT model determined poor to good agreement for the combined source of FCB (R2, E range from -2.92 to 0.71) but determined generally decreased agreement for each single source of bacteria (R2, E range from -5.03 to 0.39) potentially due to BST uncertainty, spatial variability and source characterization. The SWAT model identified critical sub-watersheds in the watershed where implementing vegetative filter strips (VFS) could be most effective to abate fecal bacteria pollution. The targeting method of VFS application to the watershed sub-basins was found to be more effective in reducing both FCB (60% vs. 42%) and sediment yield (63% vs. 33%) as compared to a random approach. The FCB source characterization methods for modeling developed in this study are general and have the potential to be extended to other watersheds. The results of this study demonstrate that the SWAT model can be used to characterize the distribution of bacteria sources within a bacteria impaired watershed and assist with developing total maximum daily loads (TMDLs) and watershed restoration strategies.

Doctor of Philosophy / Department of Civil Engineering / Alok Bhandari / Aquifers are frequently contaminated by phenolic compounds from spills, leaking underground storage tanks, or landfills. These compounds can be toxic to a variety of organisms including humans. Their disposal is restricted in many countries with strict limits for acceptable concentrations in drinking water. Phenols that are chlorinated have significantly greater toxicity and are resistant to aerobic biodegradation. Enzyme-mediated in situ stabilization has been advocated as an approach for the treatment of phenolic compounds in soils and groundwater. This research investigated the applicability of a luminol-based chemiluminescence assay to monitor transport of horseradish peroxidase (HRP) enzyme in saturated porous media. The chemiluminescence assay was optimized by varying solution conditions such as the concentration of luminol, p-iodophenol, hydrogen peroxide, ionic strength and pH. All assay components were found to affect the maximum chemiluminescene intensity. The study also evaluated the ability of HRP to mediate the removal of phenol from solution by catalyzing its oxidative polymerization in simulated aquifer conditions. HRP behaved as a conservative tracer in the column packed with Ottawa sand. The concentration of phenol in the column effluent was found to decrease by nearly 90% in the presence of HRP and H2O2 in the continuous flow system. HRP mediated oxidative polymerization of phenols resulted in the production of soluble and insoluble oligomeric products. Modification of porous media caused by the deposition of phenol polymerization products was studied and the impact of media modification on subsequent transport of phenolic contaminants was evaluated using 2,4-dichlorophenol (2,4-DCP) as a probe solute. The pore volume of the porous media was reduced due to the deposition of insoluble phenolic oligomers. The transport behavior of 2,4-DCP showed that the contaminant was retarded in the modified porous media.

Master of Science / Department of Chemical Engineering / Larry A. Glasgow / Feedlots, animal production facilities, and agricultural lands are point and non-point sources for nutrient enrichment of surrounding waterways and result in human enhanced eutrophication. Artificial elevation and increased enrichment from animal wastes, fertilizer, and runoff greatly increase the speed of this natural process and leads to degraded water quality, algae blooms, and fish kills. Phosphorous is typically the limiting nutrient for plant growth, and thus is the main focus of this paper. Phosphates enable excessive and choking plant growth that lead to depleted dissolved oxygen and excessive decaying plant matter, subsequently damaging the aquatic ecosystem. In order to provide an inexpensive and feasible solution to minimize phosphate eutrophication, a passive, vortex generating flume has been proposed to provide the necessary mixing for the removal of phosphorus from waste waters. Preliminary tests with dye tracers and electrolyte pulse injections have been conducted to model the flow characteristics and determine the residence time under a variety of flow conditions, angle of inclination and flow rate. The flume was modeled by two methods: four continuously stirred tank reactors (CSTRs) in series and as four CSTRs in series operating in parallel with a plug flow reactor (PFR). The hydraulic model fit a total of five parameters to the experimental data: Residence time, the inlet concentrations of the electrolyte pulse tracer, and the injection times of the tracer to both types of reactors. The kinetic model was built based on data collected from a different study of swine lagoons using magnesium chloride to precipitate phosphorus as the mineral struvite. The precipitation kinetics were modeled using first order and irreversible reaction and incorporated into the hydraulic model. The vortex generating flume provided an operating space that sufficiently removed phosphorus from the waste stream. Future work will include pilot scale testing of the model using waste streams and the investigation of a scour to minimize solid formation in the flume.

Doctor of Philosophy / Department of Civil Engineering / Alok Bhandari / Human activities generate large amounts of chlorinated phenolic chemicals that are often introduced into the soil environment during pesticide and insecticide application, industrial releases, and accidental spills. For example, 2,4-dichlorophenol (DCP), a derivative of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) can been found in soil within 24 hours of 2,4- D application. Horseradish peroxidase (HRP)-mediated polymerization has been proposed as an approach to remediate soils and groundwater contaminated by phenolic pollutants. Treatment with HRP results in the transformation of phenols into polyphenolic oligomers that sorb strongly or precipitate on soils surfaces. Although HRP-mediated chlorophenol stabilization has been studied extensively in surface soils, very limited scientific data is available that supports the application of this technology in subsurface materials. Hence, the focus of this study was to evaluate sorption and binding of DCP and products of HRP-mediated polymerization of DCP to model geosorbents representing subsurface geomaterials. These sorbents included two humin-mineral geomaterials and one mineral geosorbent derived from surface soils. Soil-water phase distribution of total solute in the HRP-amended systems was observed to reach equilibrium within 7 days in woodland humin-mineral soil (WHM), and within 1 day in agricultural humin-mineral (AHM) and model mineral geomaterials. For all the geomaterials used, water extraction data indicated the development of contact time-dependent resistance to extraction/dissolution of soil-associated DCP and DPP. Solute associated with WHM geomaterial was higher at the end of the study than that associated with AHM. Contact time increased DCP stabilization at all initial aqueous DCP concentrations studied. Results of this study suggest that DCP stabilization in organic geosorbents results from a combination of sorption and cross-coupling of DCP and precipitation of DPP; in inorganic soils, precipitation of DPP macromolecules is the dominant process. HRP-mediated stabilization of DCP in soils was effective and independent of the solution ionic concentration. The amount of DCP stabilized in the mineral soil was comparable to that stabilized in humin-mineral geomaterials. The research reported in this dissertation demosntrates the potential of HRP enzyme to stabilize DCP in subsurface geomaterials under variable contaminant and salt concentrations, thereby restricting its transport in the environment.

Master of Science / Department of Mechanical and Nuclear Engineering / Mohammad H. Hosni / Millions of people travel by commercial aircraft each year. The close proximity of passengers aboard an airplane leads to one of the primary reasons that air quality in an aircraft cabin is of interest. In recent years there have been multiple reported instances of people contracting illnesses after being aboard an aircraft for an extended period of time. In order to better understand air quality in an aircraft cabin, an experimental study of particulate transport in a half cabin model of a Boeing 767 was performed. In the study, both 3[Mu]m and 10[Mu]m particles were tested separately by injecting them into the cabin through a vertical tube, 609.6 mm (24 in) above the floor, at a single location on the centerline of the half cabin test section. Resulting particulate concentrations were measured at five locations along the centerline of the half cabin test section. It was found that for the 3[Mu]m particles, the normalized concentration was about one for all of the locations except directly above the injection site. Therefore, the concentrations were approximately the same as the well-mixed concentration, where the well-mixed concentration is the concentration in the test cabin if the test cabin is uniformly mixed. For the same test conditions, the normalized concentrations for the 10[Mu]m particles were well below one, around 0.1. Several more concentration measurements using the 10[Mu]m particles were taken at the same five locations, both on and off the centerline, and for different particle injection and cabin pressure conditions. The concentration results using a diffuser cone to inject the 10[Mu]m particles into the test cabin and a neutral cabin pressure were higher than the results found using the straight injection tube, but they were not very repeatable. After pressurizing the cabin to slightly above ambient pressure and using the diffuser cone, the resulting average normalized particle concentrations along the centerline were found to be between 0.4 and 1.5 and repeatable within the estimated measurement uncertainty. Therefore, it appears that the 3[Mu]m particles follow the airflow in the test cabin well, but it is not clear if the 10[Mu]m particles do as well.

Master of Science / Department of Biological & Agricultural Engineering / Stacy L. Hutchinson / Urban stormwater is one of the leading causes of water quality impairment and stream channel degradation in the United States. In an effort to address the negative effects of stormwater runoff on receiving aquatic systems, Best Management Practices for stormwater, including ecologically-designed stormwater systems, are becoming more common across the urban landscape. Throughout eastern Kansas and the rest of the Midwestern United States, prairie grasses are beginning to receive attention for their potential to enhance infiltration within these systems. However, the function of vegetated stormwater systems and the influence of factors such as vegetation age on infiltration and system performance are not well understood because monitoring data for these systems is limited. When performance data is collected, it often pertains only to the hydraulic and water quality aspects of the system but neglects any assessment of the integrity of the ecosystem functions on which the system's performance is dependent. The objective of this study was to address the need for an assessment tool that considers the ecological integrity, or health, of ecologically-designed stormwater systems, as well as to fill the gap in the literature regarding the function of ecologically-designed stormwater systems in the tallgrass prairie region. Since many of the eco-based stormwater practices in the region rely upon the establishment of native prairie grasses to enhance infiltration on the site, the specific focus of this study was to gain a better understanding of infiltration processes in ecologically-designed systems and the extent of our ability to regain these processes through prairie restoration in previously disturbed urban sites. To address these objectives, two stormwater systems at different stages of vegetative maturity were examined. In general, ecosystem health scores were higher for the more mature system and could be used to guide future management decisions at both sites. Results from the hydraulic analysis indicate the function of the system may improve over the course of the growing season, but statistical relationships between system age and infiltration rate could not be established.

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