Doctor of Philosophy, The Ohio State University, 2019, Food, Agricultural and Biological Engineering

Bioretention is an increasingly prevalent green infrastructure practice for urban and suburban stormwater management. While research has shown the ability of this technology to reduce stormwater volume and improve stormwater quality, there is a gap in knowledge regarding long term performance. Additionally, hydrocarbons are an important but understudied stormwater pollutant. Column studies indicate bioretention is an effective treatment technology for reducing hydrocarbons in stormwater flows, but there is limited research confirming this performance in field settings. To address both of these concerns, simultaneous studies were performed evaluating the hydrological performance and hydrocarbon removal of a bioretention cell six years post installation. Nine simulated storms (3.5 mm equivalent storm) were conducted, with eight of those sampled for hydrocarbon concentrations. Despite an apparent increase in preferential flow as indicated by rapid bromide tracer breakthrough and accelerated water table response rates, there was no significant difference in volume reduction between 2011 (average 53%) measurements and those done in this study (2015-2016: average 69%), after accounting for runoff volume differences. These results indicate continued effective operation of this facility, at least during small events. The effective operation was possibly due to location (suburban neighborhood) and maintenance (~monthly sediment removal). Hydrocarbon mass reductions in bioretention tests (83%), measured as total petroleum hydrocarbons, were similar to other studies while concentration reductions were lower (53%), possibly due to low input concentrations (0.58 mg/L). Hydrocarbon concentrations in the soil were higher in the upslope cell, indicating historical accumulations. However, within each cell, concentrations did not vary significantly over the year of study, indicating steady state conditions iv and no accumulation during the period of study. Comparisons of hydrocarb (open full item for complete abstract)

Committee: Jay Martin PhD (Advisor); Winston Ryan PhD (Committee Member); Kalcic Margaret PhD (Committee Member); Gabor Rachel PhD (Committee Member) Subjects: Biogeochemistry; Environmental Engineering; Sustainability

PhD, University of Cincinnati, 2004, Arts and Sciences : Biological Sciences

Ecological restoration of hazardous waste sites is a potential remediation strategy that has not been well documented. Here, we assessed natural plant community development and soil remediation on an aged petroleum refinery land treatment unit (LTU) containing recalcitrant environmental pollutants. Preliminary assessment of phytotoxicity using bioassays (Lactuca sativa L. and Solidago canadensis L.) indicated that some tolerant phenotypes would grow on LTU soil. Fourteen permanent plots (37 m²) were then established onsite to assess actual plant succession and remediation: 11 for study of natural succession and 3 to act as a control by removal of vegetation. Two soil cores were removed annually from each plot, analyzed for edaphic factors and then sequentially extracted for metals and PAHs. Analysis of contaminants indicated a 50% reduction of total petroleum hydrocarbons (TPHs) and polycyclic aromatic hydrocarbons (PAHs) in surface soil of vegetated and unvegetated plots after three years. There were no significant changes in total metal loadings. Metal content in plant root and shoot tissue was highly variable between species, but still low relative to soil levels, verifying the low bioavailability estimated from soil extracts. Plots were subsampled (1 m²) monthly for cover and abundance during the growing season, and for biomass at the end of the season. Monthly measurements of plant variables indicated that species richness increased from 28 to 57 species, cover increased from 33 to 79%, and biomass increased by a factor of four over three years. Plant growth was correlated to spatial and microclimatic factors, but contaminant loading showed no correlation. In fall of the following year, both LTU and a nearby unpolluted plant community of comparable size and successional stage were sampled as before: cover and abundance were measured in triplicate subplots (1 m²) within eleven plots. There were no significant differences in richness and percent cover between the (open full item for complete abstract)

Committee: Dr. Jodi Shann (Advisor) Subjects:

Master of Science, The Ohio State University, 1922, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1960, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Arts, The Ohio State University, 1915, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1921, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1921, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1967, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1962, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1961, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1960, Graduate School

Committee: Not Provided (Other) Subjects:

PhD, University of Cincinnati, 2023, Medicine: Industrial Hygiene (Environmental Health)

Structure fires encompass organic and inorganic fuel sources from both natural and synthetic materials. Incomplete combustion of these materials harvests several hundred byproducts including volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs). Firefighters are required to wear a certified National Fire Protection Association personal protective equipment (PPE) ensemble. In recent years, new and more advanced PPE control measures have been introduced (i.e., interface control measures, particulate-blocking materials, and the utilization of base layer clothing worn underneath the ensemble) with the intention of attenuating the ingress of known carcinogens to the inside of the gear. Providing interface control measures and adding particulate-blocking materials appeared to provide a protective benefit against less-volatile chemicals, like naphthalene and styrene. Using a fireground exposure simulator (FES), this mannequin-based study evaluated the effectiveness of four different PPE conditions with varying contamination control measures (incorporating PPE interface design features and particulate blocking materials) to protect against ingress of volatile and semi volatile contaminants in a smoke exposure chamber. Furthermore, we investigated the effectiveness of long-sleeve base layer clothing to provide additional workplace protection against skin contamination. Outside gear airborne concentrations were collected within the smoke exposure chamber. Personal air concentrations were collected from mannequins under PPE at the breathing zone, abdomen, and thigh heights and under the base layer at the abdomen and thigh heights. Sampled contaminants included benzene, toluene, styrene, and naphthalene. Workplace protection factors (WPFs) for all compounds were lower under hoods and jackets compared to under pants. Observed across all four conditions, median WPFs increased from the hood and jacket down to the turnout pant. We al (open full item for complete abstract)

Committee: Jun Wang Ph.D. (Committee Chair); Sivaraman Balachandran Ph.D. (Committee Member); Mary Beth Genter Ph.D. (Committee Member); Kenneth Fent Ph.D. (Committee Member); I-Chen Chen Ph.D. (Committee Member) Subjects: Occupational Health

Master of Science (M.S.), University of Dayton, 2023, Chemistry

Electron-electron repulsion in a quantum system facilitates the correlated motion of electrons, or electron correlation. The extent to which the movement of an electron is influenced by surrounding electrons is proportional to the correlation energy. This project explores unique electron correlation characteristics manifested in the excited singlet states of alternant hydrocarbons --- specifically, ethylene, butadiene, and hexatriene. Data was generated using the semiempirical Pariser-Parr-Pople Method, which combines molecular orbital theory approximation techniques (the Huckel and Hartree-Fock self-consistent field methods) and configuration interaction calculations. Slater determinants are used to derive configurational wavefunctions that account for all possible single- and double-electron excitations. Each electronic state can then be expressed as a linear combination of the singly- or doubly-excited configurations, with coefficients and corresponding transition energies calculated using the single or double configuration interaction method, respectively. The results indicate that certain wavefunctions --- referred to as plus and minus states --- are solely comprised of paired configurations (in equal magnitude), and all other coefficients are zero. The identical wavefunctions of the paired configurations allow for exact electron correlation symmetries to be demonstrated, yielding uncorrelated plus states (which produce an alternancy heap) and correlated minus states (yielding an alternancy hole). Analysis of each electronic state transition energy as a function of the range of electron-electron repulsion shows that at short ranges, the plus state energy increases due to the presence of alternancy heaps, while the minus state decreases because of alternancy holes. These results are consistent with the exact symmetries derived for the excited singlet states of alternant hydrocarbons.

Committee: Mark Masthay (Advisor) Subjects: Chemistry

PhD, University of Cincinnati, 2022, Engineering and Applied Science: Chemical Engineering

The concentration of carbon dioxide (CO2) in the atmosphere reaches a record high level of 412 parts per million. This high CO2 concentration has caused a series of undesirable climate effects, like erratic weather. There is a pressing need to develop a sustainable strategy to achieve negative CO2 emissions. Electrochemical CO2 reduction at ambient conditions employing renewable energy is recognized as a viable technology for the distributed generation of chemicals such as methane (CH4) and ethylene (C2H4) using CO2 recovered from industrial exhaust streams. This dissertation optimizes the CO2 reduction performance from the aspects of intrinsic catalyst design and extrinsic micro-environment regulation. Chapter 2 rationally designs metal-free graphene quantum dots (GQDs) catalysts for CO2 to CH4 conversion by regulating functional groups. The CH4 Faradaic efficiency reaches 70% at 200 mA cm-2 partial current density. Electron-donating functional groups facilitate the yield of CH4 while electron-withdrawing groups suppress CO2 reduction. Chapters 3, 4, and 5 study the role of the micro-environment in promoting the active and durable CO2 to C2H4 conversion. Chapters 3 and 4 design tandem gas diffusion electrodes (GDE), which integrate a CO-selective catalyst for complementary CO supply and a C2H4-selective catalyst for further CO reduction, to implement the cascade CO2?CO?C2H4 conversion. The C2H4 productivity was determined to be positively correlated with CO concentration (reaction order > 0). Therefore, the tandem GDEs were designed following the principle of plug flow reactor (PFR) in which CO intermediate conversion maximizes compared to the counterpart of continuous stirred tank reactor (CSTR). Chapter 3 investigates the PFR-analogous layered tandem GDEs with a CO-selective catalyst layer (CL) on the top and a C2H4-selective CL underneath. The CO concentration tops at the electrode/electrolyte interface and is consumed gradually along the electrode (open full item for complete abstract)

Committee: Jingjie Wu Ph.D. (Committee Member); Joo-Youp Lee Ph.D. (Committee Member); Maobing Tu Ph.D. (Committee Member); Yujie Sun Ph.D. (Committee Member); Peter Panagiotis Smirniotis Ph.D. (Committee Member) Subjects: Chemical Engineering

Master of Science (MS), Wright State University, 2020, Chemistry

Acid dissociation constants, often expressed as pKa values, afford vital information with regards to molecular behavior in various environments and are of significance in fields of organic, inorganic, and medicinal chemistry. Several quantitative structure-activity relationships (QSARs) were developed that correlate experimental pKas for a given class of compounds with a descriptor(s) calculated using density functional theory at the B3LYP/6-31+G** level utilizing the CPCM solvent model. A set of carbon acids provided a good final QSAR model of experimental aqueous pKas versus ΔEH2O (R2 = 0.9647) upon removal of three aldehydes as outliers. A study of saturated alcohols offered a final QSAR model with R2 = 0.9594, which was employed to confirm the behavior of the three aldehydes as hydrated species in aqueous solution. Finally, a study restricted to ketones was conducted to estimate their pKas in dimethyl sulfoxide solution. QSAR models of experimental pKas versus ΔEDMSO for the keto and enol tautomers were modest at best (R2 = 0.8477 and 0.7694, respectively). A binary linear regression was employed to incorporate descriptors representing both the keto and enol tautomers, improving the final R2 to 0.9670 upon removal of one outlier. The QSAR models presented may be utilized to estimate pKas for related compounds not offered in the existing literature or that are challenging to measure experimentally.

Committee: Paul Seybold Ph.D. (Advisor); Eric Fossum Ph.D. (Committee Member); David Dolson Ph.D. (Committee Member) Subjects: Chemistry; Organic Chemistry; Physical Chemistry

Doctor of Philosophy, The Ohio State University, 2020, Environment and Natural Resources

The ongoing shale energy revolution has transformed global energy markets and positioned the United States as a leader in oil and natural gas production and exports for the first time in generations. However, little scholarly attention has been directed toward the downstream impacts of these developments on the people and places which experience energy export activity or host related infrastructure, particularly those in rail export corridors. This research presents a first-of-its kind, cross-regional comparative analysis of community risks, risk perceptions, energy and environmental attitudes, and related discourses in oil train export corridor communities. The mixed-methods design uses household-level survey data (N=571), interview data (N=58), and news media content analysis data (N=149), to address three key knowledge gaps regarding impacts of and attitudes toward crude oil by rail in examining: 1) the influences and distributions of support, opposition, and increased concern to oil by rail; 2) views toward hydrocarbon exports as well as broader energy preferences; and 3) dominant news media and stakeholder discourses and discursive channels concerning oil train activity. Results and related recommendations include the identification of community risk perceptions, vulnerabilities, and broader energy and export attitudes as well as predictors of their variation; discussion of implications for related community energy siting and planning, news media reporting, and communications; and the contribution of novel baseline data vis-a-vis predictors of risk perception and opposition concerning oil train activity and infrastructure to the risk perception and energy impacts fields.

Committee: Jeffrey Jacquet PhD (Advisor); Kerry Ard PhD (Committee Member); Jeffrey Bielicki PhD (Committee Member); Robyn Wilson PhD (Committee Member) Subjects: Area Planning and Development; Energy; Environmental Science; Social Psychology; Sociology

Master of Science, The Ohio State University, 2020, Earth Sciences

The advent of horizontal drilling and hydraulic fracturing of black shales has met the growing global energy demands. However, the efficiency of hydrocarbon extraction from unconventional resources remains low, as just 20% of gas and 10% of fluids within the scope of a borehole are recovered. In this thesis, I present two studies to improve the efficiency of unconventional recovery through the combination of geochemistry techniques. The first study identifies hydraulic fracturing “sweet spots” within unconventional shales. Inherently in shale, some areas will lose their hydrocarbons due to brittle failures creating flow pathways that extend out of the system in the otherwise impermeable formation. Therefore, while previous attempts to define and identify “sweet spots” have avoided brittle failures, I argue that natural fractures are necessary for recovery as reactivation of these failures will create fluid flow pathways between the rock and borehole. For obvious reasons, these areas must have also retained/accumulated hydrocarbons for economical extraction. We locate these “sweet spots” through the utilization of radiogenic noble gases (e.g., 4He, 21Ne*) contained within Marcellus Shale drill cuttings. Next, I investigate the cause of carbon isotopic reversals of hydrocarbons within the Northern Appalachian Basin. The thermocatalytic cracking of kerogen fractionates the carbon isotopes of hydrocarbons (δ13C) in a predictable manner. In petroleum systems termed `normal', the δ13C values increase as the carbon number increases (i.e., δ13C-CH4 < δ13C-C2H6). However, in `reversed' systems, the opposite is seen where (i.e., δ13C-CH4 > δ13C-C2H6). The cause for these reversals is up for debate, with 6 existing hypotheses within the current literature. Wells exhibiting reversed hydrocarbons have been observed to produce larger quantities of gas than wells with normal trending gases. We investigate each hypothesis through the combination of noble gas (e.g., 3He, 4He, 20Ne, (open full item for complete abstract)

Committee: Thomas Darrah Dr. (Advisor); Frank Schwartz Dr. (Committee Member); Derek Sawyer Dr. (Committee Member) Subjects: Energy; Geochemistry; Geology

Doctor of Philosophy, The Ohio State University, 2020, Earth Sciences

The expansion of unconventional petroleum development enhanced production of natural gas and oil globally, but also raised concerns related to groundwater contamination resulting from drilling activities. Extensive research recently has focused on identifying contaminants (e.g., CH4, brines) related to drilling or natural processes, as well as the processes that emplace these contaminants into shallow groundwater systems. The integrated utilization of inert (e.g., noble gas), hydrocarbon (e.g., C1/C2+, compound-specific stable isotopes), and aqueous geochemical tracers has become a standard technique for identifying naturally-occurring hydrocarbon gas or brine from human-induced contamination. Still, it is often difficult to make determinations of groundwater contamination due to lack of understanding of the many processes that can alter the hydrocarbon and aqueous geochemistry following emplacement into groundwater (post-genetic modification) and a lack of baseline geochemical data. Advection, diffusion, mixing with primary microbial gas, microbial oxidation, and secondary methanogenesis can all obfuscate the geochemical characterization of a groundwater system making it essential to understand the effects of these individual processes. Here, numerical models were developed using a hypothetical thermogenic natural gas to illustrate how traditional geochemical tracers are affected by post-genetic modification following gas emplacement. The current work also examined the aqueous and gas geochemistry of groundwater samples collected from observation boreholes and residential drinking-water wells in the Saint-Edouard region of southern Quebec, Canada, and from drinking-water wells that were previously interpreted to contain fugitive gas contamination in Parker County, TX. In the Saint-Edouard region, the widespread presence of hydrocarbons in shallow groundwater and the relative lack of petroleum development provides a rare opportunity to understand naturall (open full item for complete abstract)

Committee: Thomas Darrah Ph.D. (Advisor); Franklin Schwartz Ph.D. (Committee Member); W. Berry Lyons Ph.D. (Committee Member); Michael Barton Ph.D. (Committee Member) Subjects: Geochemistry

Doctor of Philosophy (PhD), Wright State University, 2019, Environmental Sciences PhD

Chlorinated hydrocarbons (CHCs) in groundwater can be treated by monometallic and bimetallic metal reductants through abiotic degradation. The breakdown of CHCs is achieved by gaining electrons from those reductants and removing chlorines from CHC molecules to transform the CHCs into less chlorinated compounds. This study explored the abiotic degradation of selected CHCs by zero valent magnesium Mg0 and bimetallic Cu/Mg reductant. Results showed that zero valent Mg0 was not effective in the treatment of carbon tetrachloride (CT), chloroform (CF) and dichloromethane (DCM). In contrast, the presence of Cu in Cu/Mg bimetallic reductant significantly accelerated the degradation kinetics. Degradation kinetics were observed to decrease with time, perhaps due to particle aging. The effect of Cu loading on degradation of the above compounds was also evaluated. Increasing Cu loading yielded faster degradation rates. No significant effect of Cu loading on the extent of CHC degradation was observed. CF degradation with Cu/Mg was promoted by acidic conditions. Methane (CH4), a desirable end product, was only formed as the major byproduct in CT and CF degradation by Cu/Mg bimetallic reductant. The higher yield of CH4 from CT or CF indicated that the complete reduction pathway was more significant compared with the hydrogenolysis pathway in degradation by Cu/Mg bi-metallic reductant. Instead of relying solely on surface water or groundwater sources, potable reuse of treated wastewater is becoming an increasingly common option for bolstering water resource portfolios in water-scarce regions. However, the concern over emerging trace contaminants that persist through wastewater treatment needs to be addressed to evaluate the potential risks of wastewater reuse. Poly- and perfluoroalkyl substances (PFASs) are used in a wide range of industrial and commercial applications, and are emerging contaminants posing a threat to safe drinking water. The information about their presence in re (open full item for complete abstract)

Committee: Abinash Agrawal Ph.D. (Advisor); David F. Dominic Ph.D. (Committee Member); David Kempisty Ph.D. (Committee Member); Marc A. Mills Ph.D. (Committee Member); Mark N. Goltz Ph.D. (Committee Member) Subjects: Environmental Science

Doctor of Philosophy, University of Akron, 2019, Polymer Engineering Specialization

One type of stimuli-responsive actuator is a bending actuator, which is typically constructed by bonding together two materials with differential volumetric expansion or contraction under a stimulus e.g.solvent quality and temperature. In this dissertation, solvent and temperature sensitive polymer bilayer bending actuators were created in a facile and universal fabrication to scaling up without complicated synthesis and delicate technology. Solvent-responsive bilayer was produced by crosslinking poly(dimethylsiloxane) (PDMS) oligomers in terms of variable fabrication parameters through hydrosilylation. Before vulcanization, the base-tocrosslinker weight ratios determined a crosslinking extent or gel fraction and subsequently, dominated the equilibrium swelling ratio and linear swelling expansion ratio of PDMS rubbers. Except for the base-tocrosslinker weight ratios, the gel fraction of the bottom layer has a predominant impact of the bending extent of the bilayer in terms of the curing time of the bottom layer and deposition order of PDMS layers. The optimum bending degree of the bilayer was estimated by using a simulation model derived from Timoshenko's equation in the case of bimetallic thermostat. Ultimately, the calculated base-to-crosslinker weight ratio of the top layer of the bilayer was significantly corresponded to the experimental data. A different type of bilayer bending actuators with respect to temperature was presented. These temperature-activated actuators containing the phase-change materials would make it potential to detect latent heat in the nature and conduct the thermal-management. A self-contained thermal bending actuator based on a polymer bilayer where the actuation is driven by the expansion and contraction of paraffin wax undergoing solid-to-liquid phase transition. Bilayer films consisting of active, wax-containing polymer layer and passive, wax-free polymer layer were fabricated using commercially available polymers and a commercially (open full item for complete abstract)

Committee: Kevin Cavicchi (Advisor); Mark Soucek (Committee Member); Nicole Zacharia (Committee Member); Li Jia (Committee Member); Alper Buldum (Committee Member) Subjects: Materials Science; Polymer Chemistry; Polymers