Master of Science in Engineering, Youngstown State University, 2020, Department of Civil/Environmental and Chemical Engineering

Mentor Marsh, in 1966, was declared to be the first National Natural Landmark along with the Great Lake's sites due to the diverse presence of the richest community of wetland species. However, anthropogenic activities during the late 1960s led to the severe salt intrusion in Mentor Marsh. This resulted in the immense loss of maple swamp forest followed by the successful invasion of dense-growing, salt-tolerant Phragmites australis responsible for the outbreak of several fires. Although, successful restoration of Mentor Marsh ecology has been a prime concern, yet its technical feasibility can only be achieved through the proper identification of salinity hotspots. Therefore, this research study jointly investigates the spatiotemporal variability of both water and soil salinity. Assessment of water salinity was undertaken through the development of a watershed model and establishment of gauge stations to evaluate the salinity diversion due to the routing of Blackbrook creek, whereas remote sensing along with field measurements approach has been employed for the effective monitoring of soil salinity. A commonly used watershed model, Soil and Water Assessment Tool (SWAT) was developed using necessary inputs to delineate Mentor Marsh watershed, which was calibrated (November 2016-March 2018) and validated (April 2018-September 2019) on a monthly basis against the observed flow generated from the stage-discharge curve at the upstream section of Blackbrook creek. The statistical parameters used for model performance as Coefficient of determination (R2) and Nash Sutcliffe's Efficiency (NSE) were 0.89 and 0.88, respectively in the calibration phase while for the validation phase were 0.85 and 0.81, respectively. The salinity at the outlet of old and diverted Blackbrook creek was computed using the flow generated from the model and real-time recorded salinity data. The daily salinity at the routed outlet varied between 10.33 kg/d to 602.44 kg/d, while at the old Blackbroo (open full item for complete abstract)

Committee: Suresh Sharma PhD (Advisor); Richard Deschenes PhD (Committee Member); Peter Kimosop PhD (Committee Member) Subjects: Civil Engineering; Environmental Engineering

Master of Science (MS), Ohio University, 2024, Biological Sciences (Arts and Sciences)

Eastern Hellbenders (Crytobranchus a. alleganiensis) have suffered enigmatic, range- wide declines over the past decades. Persisting populations are skewed towards larger, older adults, suggesting that reduced recruitment is responsible for these declines, with degraded water quality, specifically elevated conductivity, implicated as a main contributor. Successful fertilization and the resilience of eggs under high conductivity conditions suggest deleterious effects during larval development. We experimentally assessed the effects of chronic exposure to elevated conductivity (1000 μS/cm) on wild Eastern Hellbender larvae hatched in a lab, as well as the effects of switching from low conductivity (100 μS/cm) to high, and vice versa, on Eastern Hellbenders during early larval development. We assessed mortality over 72 days post-hatching, with half of the larvae switched from their original conductivity treatments to the other over five days beginning at 33 days post-hatching. Chronic exposure to elevated conductivity resulted in significant mortality. Additionally, switching larvae from low conductivity to high resulted in increased mortality, while switching larvae from high conductivity to low increased survival. We also assessed larval morphology and swimming performance and found significant negative effects of chronic exposure to elevated conductivity on both body mass and multiple measures of morphology (length and width). We observed similar effects in animals switched from low conductivity to high, while switching animals from high conductivity to low resulted in only marginally increased mass and morphological measures, demonstrating their inability to compensate for initially depressed growth rates even after being returned to more optimal conditions. Despite altered size and morphology, elevated conductivity did not impact locomotor performance, though switching conductivities, regardless of direction, did result in increased burst distance. We measured who (open full item for complete abstract)

Committee: Shawn Kuchta (Advisor); Viorel Popescu (Committee Member); Kelly Johnson (Committee Member) Subjects: Biology; Conservation; Ecology; Endocrinology; Freshwater Ecology; Molecular Biology; Morphology; Organismal Biology; Wildlife Conservation

Doctor of Philosophy, Miami University, 2021, Microbiology

Photosynthesis is one of the most important processes on Earth by which organisms convert solar energy into usable forms of energy. Linear electron flow (LEF) and cyclic electron flow (CEF) constitute two major pathways in photosynthesis. While LEF leads to production of both ATP and NADPH, CEF only produces ATP that helps balance the ATP:NADPH ratio required for carbon fixation. CEF also plays a major role during acclimation to several environmental stressors. However, the regulation and mechanism by which CEF operates is still not clearly understood. Recent studies have shown that formation of a protein supercomplex with PSI appears to be essential for induction of CEF in several model organisms. However, both supercomplex formation and CEF induction have been mainly studied under short-term, transitory stress conditions. In addition, the role and mechanism by which organisms may rely on CEF to survive in their natural habitat and acclimate to stress over a long period of time has not been considered. In this study we compared how three photosynthetic organisms (one model alga, Chlamydomonas reinhardtii; two extremophiles, C sp. UWO241 and C. sp. ICE-MDV) utilize CEF to cope with their natural environment and adapt to steady-state environmental stress. To that end, the objectives of this thesis were i) to elucidate the role of CEF in long-term salinity acclimation ii) to understand the downstream changes associated with increased CEF, and iii) to identify whether PSI-supercomplexes are associated with increased CEF during salinity acclimation. We hypothesized that a stable PSI-supercomplex is required for high CEF, which in turn supports strong carbon fixation capacity for production of downstream metabolic products important for long-term acclimation to salinity stress. We showed for the first time, that increased CEF in UWO241 leads to excess ATP production and rewiring of downstream metabolism under high salinity. Next, we showed that a l (open full item for complete abstract)

Committee: Rachael Morgan-Kiss (Advisor); Xin Wang (Committee Member); Annette Bollmann (Committee Member); Donald Ferguson (Committee Member); Carole Dabney-Smith (Committee Member); Luis Actis (Committee Member) Subjects: Biochemistry; Ecology; Environmental Science; Microbiology; Physiology; Plant Biology

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

Though fossil fuels have met the growing global energy demand, after three centuries of combusting fossil fuels the world is facing the environmental catastrophe: global warming and climate change. To reduce the risks of global warming and climate change, there has been an international effort to develop and improve low-carbon energy technologies, which is now driving the energy transition from fossil fuels to renewables. Among the renewable sources of energy, salinity gradient power is often overlooked. The objective of this dissertation is to both address current challenges in reverse electrodialysis (RED) which harnesses energy from salinity gradients and study on a novel capacitive reverse electrodialysis (CRED) process. When two solutions with different salinities are mixed through engineered systems, the salinity gradient can create electric power. Salinity gradient energy is estimated that theoretically 0.8 kW/m3 (equivalent to the amount of hydroelectric power from a dam higher than 280 meters) could be extracted at the point where fresh water streams into the sea. The larger the difference in concentration, the more energy becomes available. However, including natural seawater, highly saline solutions contain multivalent ions that deteriorate the RED performance significantly by increasing electrical resistance of ion exchange membranes. Some multivalent ions form precipitations in the system and these precipitations can be exacerbated at the electrode system where electrochemical reactions take place when operating voltage is high enough, such as in pilot-scale operations. These electrochemical reactions restrict the scaling up of the RED process. The CRED system is a relatively new technology in salinity gradient energy. This technology combines the conventional RED and capacitive mixing (CapMix), another new technology. The CRED process is believed to be operated even above 3–4 V without pH-changes. This indicates that this technology can control elect (open full item for complete abstract)

Committee: Soryong Chae Ph.D. (Committee Chair); Dionysios Dionysiou Ph.D. (Committee Member); Junhang Dong Ph.D. (Committee Member); Jin-Soo Park Ph.D. (Committee Member); Vesselin Shanov Ph.D. (Committee Member) Subjects: Environmental Engineering

Master of Science in Chemical Engineering, Cleveland State University, 2018, Washkewicz College of Engineering

Of the many alternative resources capable of generating biofuel, microalgal oil serves as a promising feedstock. Unfortunately, biodiesel production from microalgae is currently hindered by high operational costs. One primary causes for these high costs is the large quantity of freshwater required for cultivation. This experiment was designed to assess the feasibility of growing the green, freshwater microalgae Scenedesmus dimorphus in an increasingly saline environment. Both average yield coefficients and growth rates were monitored with increasing salt concentration. Determination of average yield coefficients allows for process scale-up and the optimization of production costs by minimizing raw material waste. Salinity was measured in terms of total specific gravity (TSG). The typical TSG levels for freshwater and open seawater are 1.000 and 1.025-1.030, respectively. Microalgae were grown in a 5L photobioreactor in batch mode with freshwater, 1.006, and 1.009 TSG media. The growth rate, average yield coefficients and lipid content were analyzed under these conditions. Low salinity levels had little impact on growth rate, while increasing salinity to 1.009 TSG resulted in a reduction in the growth rate by 40%. Substrate consumption over time was monitored using Inductively Coupled Plasma – Optical Emission Spectroscopy to calculate the average yield coefficients for magnesium, iron and phosphorus. Magnesium and iron average yield coefficients increased from freshwater values at 1.006 TSG, while the average yield coefficient for both of these elements showed a reduction from freshwater values at 1.009 TSG. The average yield coefficient for phosphorus did not change at 1.006 TSG but increased at 1.009 TSG. Lipid content and biodiesel fuel properties were also calculated to estimate the quality of fuel derived from S.dimorphus oil. Lipid content seemed to increase from freshwater (1.96% up to 3.28%) to 1.011 TSG but decline at a TSG of 1.015. The cetane number, (open full item for complete abstract)

Committee: Joanne Belovich Dr. (Committee Chair); Jorge E. Gatica Dr. (Committee Member); Xiang Zhou Dr. (Committee Member) Subjects: Chemical Engineering

Master of Science in Engineering, Youngstown State University, 2018, Department of Civil/Environmental and Chemical Engineering

The Mentor marsh was the first declared a National Natural Landmark in 1966 and became a nature preserve in 1971 in the State of Ohio. Despite being affected by salt pollution and other physical challenges, it still has a tremendous economic value, and will rise if it is restored. The Marsh was specifically dominated by catastrophic salt pollution due to the development of different human and industrial activities, especially between the late 1950's and late 1970's. The water salinity of the marsh varied from oligosaline (500 to 5,000) mg/L to hypersaline (above 40,000 mg/L) during that period. Salinity is a crucial environmental problem in the Mentor Marsh leading to profound consequences in wetland plants and aquatic habitats; including the rapid development of Phragmites australis in the downstream marshland. These Phragmites australis were very vulnerable to capture fire. While several studies were conducted in the past in the Mentor marsh, hydrologic investigation of the watershed has not been conducted yet, due to the lack of monitoring stations and long-term data records. Since the Mentor marsh watershed is a small ungaged watershed, and data is only being collected for a short duration, the prediction of flow with limited data invites certain degree of uncertainty. Therefore, monitoring stations were established in two small tributaries of Blackbrook Creek and Marsh Creek, for real time data recording of flow stage, water conductivity, water temperature, and atmospheric pressure in hourly mode using Levelogger and Barologger data logging devices. Similarly, the creek cross-section, water velocity and water stage were recorded intermittently with direct field observation to develop a rating curve and generate the continuous streamflow data. The hydrologic model, Soil and Water Assessment Tool (SWAT), was developed using climate data from National Climatic Data Center (NCDC) and Digital Elevation Model (DEM), land cover and soil data from the United States Dep (open full item for complete abstract)

Committee: Suresh Sharma PhD (Advisor); Tony Vercellino PhD (Committee Member); Peter Kimosop PhD (Committee Member) Subjects: Civil Engineering; Environmental Engineering; Hydrologic Sciences; Hydrology; Water Resource Management

PhD, University of Cincinnati, 2018, Arts and Sciences: Geography

Geoarchaeology offers a crucial set of skills and approaches for studying the human past. Without a critical assessment of environmental conditions, especially in studying cultural groups living in locations during climatic periods different than today, an absent or limited dateset may preclude studying how human ecology in an area has varied through time. In Northeast Africa, the African Humid Period (AHP) was the latest in a series of Saharan pluvials studied using carbonates. Previous evidence shows desert paleolakes were the result of surface discharge from a regionally higher water table that created a wetter environment beyond what runoff from increased seasonal precipitation could have supported alone. In research reported here, carbonate morphology and oxygen isotope composition of carbonate samples are used to develop a conceptual model demonstrating carbonate accumulation in areas near the Nile River as a result of a regional rise in the water table driven by greater precipitation during pluvial periods. Morphological evidence shows a variety of formative environments at key topographic locations indicating regular water availability at elevations above that modeled for contemporary Nile River flood heights. Results from oxygen isotope analysis indicate locations dominated by evaporative enrichment at the highest elevations, transition to stable isotopic conditions at intermediate elevations, and a return to more enriched values at low elevations in proximity to modeled Nile flood zones where discharging groundwater and Nile floodwaters would have intermixed. Estimated d18O ranges for soil water reconstructed from precipitated carbonates suggest a persistently available moisture, largely unaffected by evaporative enrichment, with a similar isotopic range as the groundwater which supported desert paleolakes. Given sample distances and elevations relative to the river, the monsoonal precipitation pattern, the temporal duration of relatively invariant isoto (open full item for complete abstract)

Committee: Nicholas Dunning Ph.D. (Committee Chair); Richard Beck Ph.D. (Committee Member); Hongxing Liu Ph.D. (Committee Member); Lewis Owen Ph.D. (Committee Member); Kevin Raleigh Ph.D. (Committee Member) Subjects: Geography

Doctor of Philosophy, The Ohio State University, 2017, Environmental Science

The cryosphere is shrinking as a result of climate change. Mountain glaciers, a key component of the cryosphere, serve as headwaters to glacier meltwater streams which support communities of stenothermic organisms. The Tibetan plateau is known as "the Third Pole" for its high number of glaciers, yet very few scientific papers have been published on aquatic invertebrate ecology of glacier-fed streams in the region. On the edges of the Tibetan Plateau in Southeast Tibet's Hengduan mountains, monsoonal temperate glaciers extend well below the treeline as valley glaciers, and are perhaps the most endangered cryosphere-dominated streams in the world due to their low latitudes and altitudes, which makes them sensitive to atmospheric temperature changes. The glaciated headwaters of the Mekong and Yangtze Rivers comprise a small fraction of the annual river discharge, yet at a local scale provide glacial meltwater that supports endemic and potentially rare species. Water temperature and channel stability differ between seasons due to the torrential flow from glacial meltwater during the summer melt season. The Milner & Petts (M&P) model of macroinvertebrate presence in glacier streams was based on the environmental factors of water temperature and channel stability during the summer melt season. In low temperature water close to the glacier, the macroinvertebrate communities are generally limited to Diamesinae chironomids, and further downstream more taxa are found where water temperature and channel stability increase. Therefore, temperature and channel stability are examined as potential limiting factors on the distribution of invertebrate communities, with the goal to compare the insect communities in Southeastern Tibet's glacier-fed streams with the widely-accepted M&P model of invertebrate community structure. Since discharge and hydrology may influence invertebrate distribution in glacier streams, hydraulic characteristics and invertebr (open full item for complete abstract)

Committee: Lanno Lanno Dr. (Advisor); David Denlinger Dr. (Committee Member); Richard Moore Dr. (Committee Member); Donald Dean Dr. (Committee Member) Subjects: Environmental Science

Master of Science, The Ohio State University, 2016, Food, Agricultural and Biological Engineering

Many food processers use salt, resulting in high strength, high salt content wastewater. The goal of this study was to determine the impact of salt concentration on the treatment of turkey slaughterhouse wastewater using sand/gravel bioreactors. Six unsaturated sand/gravel columns were intermittently dose treating the wastewater in a single pass. Turkey processing wastewater served as the control and 3 g/L and 6 g/L of table salt were added to wastewater for treatment is duplicate laboratory columns. BOD5 and NH3-N removal was measured during the 74-day experiment. The BOD5 removal achieved and maintained over 99% after day 21 at all salt levels. The NH3-N removal achieved over 99% removal after day 32. The conductivity of the effluent matched the influent indicating that the treatment system did not remove salt. It was concluded from this study that sand/gravel bioreactors were able to treat high strength, high salinity (up to 0.6%) turkey slaughterhouse wastewater. The biofilm developed on the sand/gravel surface is the functional part of wastewater treatment. In this study, ATP was measured to investigate the impact of salt on the biomass in the treatment system. Sand/gravel samples were collected from each layer of the columns in the wastewater control and wastewater plus 6 g/L salt. The results showed that salt had an initial inhibition on the biomass in the system. System performance decreased as the biomass declined. After the biomass reached a steady level, the treatment performance was maintained at high level. The study also found that the coarse sand layer was the most active layer treating wastewater.

Committee: Karen Mancl (Advisor); Olli Tuovinen (Committee Member); Yebo Li (Committee Member) Subjects: Agricultural Engineering

MA, University of Cincinnati, 2016, Arts and Sciences: Anthropology

The occurrence of salt pollution associated with Ancestral Puebloan water management systems in the high desert environment of Chaco Canyon, New Mexico is debatable. This study measured the salinity levels of sediment samples obtained from twelve solid-sediment cores and two profiles excavations from Robert's Great House and vicinity. This study demonstrates that the soil salinity is well below deleterious levels for maize production. Additionally, the salts identified by Powder x-ray diffractometry are plant friendly sulfates rather than toxic chlorides. In addition to their natural occurrence, sulfates can be anthropogenic as they are an important aspect of Puebloan culture.

Committee: Vernon Scarborough Ph.D. (Committee Chair); Kenneth Tankersley Ph.D. (Committee Member) Subjects: Archaeology

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

When a dispersant is applied to an oil slick, its effectiveness in dispersing the spilled oil depends on various factors such as oil properties, wave mixing energy, temperature of both oil and water, and salinity of the water. Estuaries represent water with varying salinities. In this study, three salinity values in the range of 10-34 ppt were investigated, representing potential salinity concentrations found in typical estuaries. Three oils were chosen to represent light refined oil, light crude oil and medium crude oil. Each of the oils was tested at three weathering levels to represent maximum, medium and zero weathering. Two dispersants were chosen for evaluation. A modified trypsinizing flask termed the ‘Baffled Flask' was used for conducting the experimental runs. A full factorial experiment was conducted for each oil to investigate the effect of salinity on three environmental factors: temperature (2 levels), oil weathering (3 levels) and mixing energy (150,200 and 250 rpm). Each experiment was replicated four times in order to evaluate the accuracy of the test. Evaluations were conducted to study the effect of different variables like salinity, weathering, mixing speed and temperature on dispersant effectiveness. Statistical analysis of the data was performed separately on each of the nine oil-dispersant combinations, which revealed the significant factors for each of the combinations. A linear regression model was fit to the experimental data collected

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

Doctor of Philosophy, Miami University, 2009, Zoology

This dissertation consists of three chapters, each of which addresses a topic in one of three related categories of research as required by the Ph.D. program in ecology as directed through the Department of Zoology at Miami University.Chapter 1, Phylogeographic analysis reveals multiple cryptic species of amphipods (Crustacea: Amphipoda) in Chihuahuan Desert springs, investigates how biodiversity conservation and the identification of conservation units among invertebrates are complicated by low levels of morphological difference, particularly among aquatic taxa. Accordingly, biodiversity is often underestimated in communities of aquatic invertebrates, as revealed by high genetic divergence between cryptic species. I analyzed PCR-amplified portions of the mitochondrial cytochrome c oxidase I (COI) gene and 16S rRNA gene for amphipods in the Gammarus pecos species complex endemic to springs in the Chihuahuan Desert of southeast New Mexico and west Texas. My analyses uncover the presence of seven separate species in this complex, of which only three nominal taxa are formally described. The distribution of these species is highly correlated with geography, with many present only in one spring or one spatially-restricted cluster of springs, indicating that each species likely merits protection under the U.S. Endangered Species Act. I present evidence suggesting that habitat fragmentation, long-distance colonization, and isolation-by-distance have occurred at different temporal and spatial scales within this system to produce the lineages that I report. Chapter 2, Detecting conservation units using morphological versus molecular criteria: evaluating the Gammarus pecos species complex as a test case, compares the results of morphological versus molecular biodiversity assessments within the G. pecos species complex. I compared results from an earlier morphology-based study to my results from screening 166 COI gene sequences according to Moritz' Evolutionarily Significant (open full item for complete abstract)

Committee: David Berg PhD (Advisor); John Bailer PhD (Committee Member); Brian Keane PhD (Committee Member); Nancy Solomon PhD (Committee Member); Bruce Steinly PhD (Committee Member) Subjects: Bioinformatics; Biology; Biostatistics; Ecology; Environmental Science; Freshwater Ecology; Genetics; Hydrology; Molecular Biology; Zoology

Doctor of Philosophy, University of Akron, 2012, Integrated Bioscience

The modern synthesis of paleontology with evolutionary biology has successfully integrated population ecology into the study of the fossil record. While it may prove impossible to measure and account for the important processes that structure communities through time, the integration of community ecology into paleoecology remains to be done to further the modern synthesis. This dissertation attempts to integrate community ecology into the study of a lacustrine ostracode metacommunity across space today and through the mid Holocene on San Salvador Island, Bahamas. Patterns of community change across space today are investigated by comparing the live/dead agreement in taxonomic composition and rank-abundance of species in seven lakes. This taphonomic study establishes that live/dead agreement of ostracode assemblages is high in all lakes save one. Therefore, sampling of death assemblages, as is common in many paleolimnolgical studies, can be used to investigate changes in alpha and beta diversity of assemblages across time and space. Death assemblages were then sampled from thirty-two lakes on San Salvador to investigate the metacommunity dynamics that explain patterns of beta diversity of communities. I found that beta diversity was most strongly controlled by the local environment in which communities live with the change in communities most strongly correlated with changes in a complex hydrological gradient of: conductivity, dissolved oxygen, and alkalinity. After establishing that the metacommunity dynamics conformed to a species sorting model, I exploited the association between ostracode assemblages and conductivity to create a statistical model that used changes in ostracode assemblages to predict changes in conductivity within individual lakes on San Salvador. This model was then applied to archives of ostracode assemblages from the mid-Holocene to today to create a record of changing conductivity through time in three lakes. The model reveals large, hi (open full item for complete abstract)

Committee: Lisa E. Park Dr. (Advisor); Francisco B.-G. Moore Dr. (Committee Member); Jean J. Pan Dr. (Committee Member); John M. Senko Dr. (Committee Member); Alison J. Smith Dr. (Committee Member) Subjects: Paleoecology