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Water and other volatiles (e.g. CO2, H2, CH4, etc.) are crucial components on Earth that ensure the habitability of the planet and play an important role in many geological processes. Small aliquots of these fluids can be preserved in the geological record as fluid inclusions and can provide valuable information about the physical and chemical environment in which they formed. The ocean is the largest water reservoir on the Earth's surface, and seawater participates in important water-rock reactions such as hydrothermal alteration of the ocean floor, a process that is currently in the spotlight for hypotheses on the origin of life, as it is an environment where generation of abiotic carbohydrates occur. The ocean chemistry varied in the geologic past to reflect major changes in the intensity of weathering, rates of midocean ridge hydrothermal discharge, changes in the climate and atmospheric CO2 concentration, and also played an important part in mass extinction events. Understanding the history of Earth's ancient oceans may hold the key to answer some of the important questions about the future of the Earth. Today, oceans hold valuable resources, such as offshore basalt formations which have been considered for submarine CO2 sequestration to mitigate greenhouse gas emissions associated with global warming. In the chapters of this dissertation, the reader will be presented with studies using fluid inclusions to advance our knowledge about the chemical evolution of seawater and reaction kinetics involving CO2, seawater and olivine – an abundant mineral in the oceanic lithosphere. Chapter I "Redox conditions in Late Permian seawater based on trace element ratios in fluid inclusions in halite from the Polish Zechstein Basin" describes application of a new redox proxy for paleo-seawater that involves analysis of redox-sensitive trace elements (e.g., Fe, Mn, U, V, Mo) in ancient seawater trapped as fluid inclusions in halite. Chapter II "Partitioning behavior of trace elements during evaporation of seawater" investigates the behavior of trace elements during the evaporation of seawater. This information is required to interpret trace element data from fluid inclusions in halite. In Chapter III "In situ monitoring of the carbonation of olivine under conditions relevant to carbon capture and storage using synthetic fluid inclusion micro-reactors: Determination of reaction rates", fluid inclusions are used as micro-reactors to monitor the reaction progress of olivine carbonation in situ and in real time at elevated temperatures (50-200 °C) and pressures using non-destructive analytical techniques such as Raman spectroscopy. / Doctor of Philosophy / Many geological processes on Earth involve water and other volatiles (e.g. CO2, H2, CH4, etc.) which are crucial components that ensure the habitability of the planet. These fluids can be preserved in the geological record in the form of fluid inclusions which are small aliquots of fluids trapped in minerals that provide information about the physical and chemical environment in which they formed. The majority of water on the Earth's surface is stored in the oceans. Seawater participates in important water-rock reactions, one of which is the hydrothermal alteration of the ocean floor. This reaction is in the spotlight currently because it represents an environment where generation of abiotic carbohydrates occur, giving rise for hypotheses about the origin of life on Earth. The chemical composition of seawater varied in the geologic past reflecting major changes in the intensity of weathering, discharge rate of midocean ridge hydrothermal systems, climate, and atmospheric CO2 concentration, and affected the survival of various marine species throughout Earth's history. For example, periodic extensions of oxygen minimum zones in the oceans played an important part in mass extinction events in the last 488 million years. Understanding the history of Earth's ancient oceans may hold the key to answer some of the important questions about the future of the Earth. Today, oceans hold valuable resources, such as offshore basalt formations which have been considered for submarine CO2 sequestration to mitigate greenhouse gas emissions associated with global warming. This dissertation explores ways to use fluid inclusions to advance our knowledge about the chemical evolution of seawater in the past and present, and the reaction of seawater with CO2 and olivine – an abundant mineral in the oceanic lithosphere – to facilitate long-term storage of CO2 in minerals to decrease the rate of global warming. Chapter I describes the application of a new redox proxy for paleo-seawater that involves analysis of redox-sensitive trace elements (elements whose solubility changes significantly as the oxidation state changes, such as Fe, Mn, U, V, Mo) in ancient seawater trapped as fluid inclusions in halite. The results suggest that trace element abundances in fluid inclusions in halite vary in response to redox changes in seawater and provide a potential redox proxy. Chapter II investigates the behavior of trace elements during the evaporation of seawater. This information is required to interpret trace element data from fluid inclusions in halite. The results of this study indicate that some elements remain in the water during evaporation of seawater (e.g. Li, B, Mo, U), while others are partially removed by precipitation of various mineral phases (e.g. Ba, Sr, Cs, Rb, Mn, V) as seawater evaporates. In Chapter III, fluid inclusions are used as micro-reactors to monitor the reaction progress of olivine carbonation in situ and in real time at elevated temperatures (50-200 °C) and pressures using non-destructive analytical techniques such as Raman spectroscopy. The results highlight that this reaction occurs rapidly, which makes it an ideal candidate for safe storage of CO2 by commercial CO2 injection projects in mafic and ultramafic rocks.

Increased loading of dissolved ions (salinization) and trace elements from surface coal mining is a common alteration to headwater streams in the central Appalachian region. However, temporal and spatial trends of water quality and associated influences on biota in these stream systems have not been well-studied. To address this research need, I analyzed temporal trends in specific conductance, ion matrix, and benthic macroinvertebrate communities in 24 headwater streams, including 19 influenced by surface mining, from 2011-2019. There was limited evidence of recovery of water chemistry or macroinvertebrate communities in these streams, indicating lasting impacts from surface coal mining. Among benthic macroinvertebrates, Ephemeroptera and the scraper functional feeding group were most-impacted by chronic salinization in study streams. In addition, I analyzed spatial patterns of water chemistry in a subset of these streams using synoptic sampling of multiple constituents under baseflow and highflow conditions. Study results indicate that water chemistry is spatially dynamic and can be influenced by both groundwater dilution and inputs from tributaries. Lastly, I investigated patterns in selenium bioaccumulation across and within streams, from particulate matter to top trophic levels (i.e. fish and salamanders). I found that benthic macroinvertebrates had the highest concentrations of selenium in these ecosystems, with lower concentrations in salamander and fish species. However, there was limited evidence of longitudinal trends in bioaccumulation dynamics downstream of mining impacts. Collectively, this work indicates long-term (ca. decades) coal-mining influences but also highlights future research needs to better understand downstream impacts to water quality and biotic communities. / Master of Science / Surface coal mining affects water quality in central Appalachian headwater streams. However, long-term and downstream patterns of impacted water quality and potential effects on aquatic life have not been well-studied. To address this research need, I analyzed trends in water quality parameters and aquatic insect communities in 24 headwater streams from 2011-2019. There was limited evidence of recovery of water chemistry or aquatic life in these streams, indicating lasting impacts from surface coal mining. Certain aquatic insects including Ephemeroptera (mayflies) appear to be more impacted than others by long-term altered water quality. In addition to trends over time, I also analyzed downstream variation in water chemistry in a subset of these streams under baseflow conditions and after a rain event. Results indicate that water chemistry can vary greatly within a stream network and is influenced by tributary inputs and dilution from groundwater. Concentrations of the trace element selenium can also be elevated as a result of surface mining. This is of environmental concern because selenium can biomagnify, where concentrations increase in organisms higher in the food chain and can cause toxic effects. Here, I investigated selenium bioaccumulation patterns across organisms in the food chain and with distance downstream across six headwater streams. I found that aquatic insects had the highest concentrations of selenium, with lower concentrations in salamanders and fish. This work indicates that surface coal mining has longterm (ca. decades) effects on headwater streams, but also points to future research to better understand downstream impacts to water quality and aquatic life.

It is believed that the presence of certain trace elements in the skin may play an important role in the formation of melanomas. In this work, neutron activation analysis and x-ray fluorescence analysis were used to determine trace element concentrations in cancerous, noncancerous and normal swine skin samples and in non-cancerous and normal swine tissue samples. In-vivo x-ray fluorescence analysis was also used to determine trace element concentrations in cancerous, non-cancerous, and normal swine skin. Data on forty-eight trace elements in each sample were obtained and correlated. The limited number of cancerous samples made definitive conclusions about trace element imbalances uncertain. Nevertheless, the in-vivo XRFA method was shown to be a very useful method for trace element determination. Additionally, good base line data were obtained for trace element concentrations in a variety of organs of Sinclair miniature swine. / Master of Science

The appearance of synthetic fertilizers on the market has increased the interest in the so-called "minor elements". Much work with water and sand cultures has proven the necessity of these elements for successful plant growth. However, the need for these elements in crop production on field soils has not been studied intensively, nor have we sufficient knowledge as to the effect of our changing fertilizer practices on the necessity for minor elements. A number of field studies to determine the necessity of boron, manganese, zinc, copper and ether minor elements, when applied singly or in combinations of two or more, have given phenomenal increases in yields under certain plant and soil conditions. Under other conditions there has been no response from their use when applied to the soil either singly or in combinations of two or more elements. It is the purpose of this study to determine under what soil conditions the need of minor elements becomes a part of our soil management problem and what part natural Chilean nitrate of soda plays in preventing and correcting this condition. Also this investigation was developed to give a comparison of yield and growth of various crops grown intensively on a number of soil types where fertilized with purified carriers of nitrogen, phosphorus and potassium and where these elements were supplied from commonly used commercial carriers. Another purpose of this study was to determine how long these soils could be cropped before minor elements would become a limiting factor in crop production as shown by yields and deficiency symptoms. / Master of Science

The bioessential trace metals (e.g. zinc, copper and iron) are primarily excreted via the gastrointestinal trace in normal man and animals. Although urinary losses of these trace metals are usually minimal, they have been reported to be markedly elevated during periods of physiological and pathological stress. The possibility that the decreased plasma insulin to glucagon ratio during episodes of stress is responsible for increased urinary trace metal excretion was examined in normal and streptozotocin-diabetic rats. Induction of the diabetic condition resulted in a rapid and persistent increase in the quantities of zinc, copper and iron lost in the urine daily. Diabetic rats excreted 3.4, 5.0, and 4.9-fold more zinc, copper and iron, respectively, at 14 days after injection with the diabetogenic drug than the controls. Insulin treatment of diabetic rats significantly reduced the daily urinary losses of these micronutrients, indicating that altered hormonal balance was the primary cause for elevated urinary excretion. Enhanced urinary losses of these metals were not associated with decreased concentrations of zinc, copper and iron in plasma, liver and kidney. Various processes, including the filterability of the metal, glomerular filtration rate, renal tubular reabsorption and transtubular secretion have been reported to influence urinary excretion of trace metals. Initial studies have been conducted to assess the influence of altered endocrine status on the characteristics of zinc binding and transport by renal brush border membrane vesicles (BBMV) in vitro. The accumulation of zinc by BBMV was found to be temperature dependent. No apparent differences in the binding and intravesicular accumulation of zinc by brush border membrane vesicles prepared from normal and STZ-diabetic rats were observed. Likewise, the efflux of zinc from BBMV prepared from control and diabetic renal cortex was similar. These results indicated that the potential for zinc reabsorption is not altered in the diabetic rats. In vivo studies are required to further assess the characteristics of zinc reabsorption in the native milieu. / M.S.

Food waste is a desirable feedstock for anaerobic digestion because it is high in moisture and is an easily degradable material. However, mono-digestion of food waste often fails due to the accumulation of volatile fatty acids. Supplementing trace elements is one strategy to combat this issue. This study examined the effect of supplementing trace elements (iron, nickel, selenium, molybdenum, magnesium, zinc, calcium, copper, manganese, cobalt) on the methane yield and organic waste destruction of anaerobically digested food waste. Methane yield of food waste with and without the inorganic salt trace element was determined by the gas density-based biomethane potential method at mesophilic (37°C) conditions over 30 days. The three treatments were inoculum only, food waste and inoculum, and food waste and inoculum with an added trace element solution. There was no significant difference between treatments in terms of waste stabilization (percent volatile solids, total solids, and total chemical oxygen demand reduction) between treatments. The average cumulative biogas produced was 41% higher, and the average total cumulative methane produced was 23% higher in the treatment with the trace element supplement. Mean methane yield was not different (p > 0.05) between treatments over the 30 days, and there was no difference (p > 0.05) in biomethane potential between treatments. In addition, greenhouse gas reduction potential was estimated from food waste streams in Montgomery, VA using anaerobic digestion. The purpose of this work was to (1) estimate the total mass of food waste produced in Montgomery, VA in a year, (2) use the results from the biomethane potential analyses to inform the sizing of a theoretical community digester in Montgomery, VA, and (3) estimate the greenhouse gas reduction potential of anaerobically digesting the food waste instead of sending it to landfill. Greenhouse gas reduction was calculated using the Climate Action Reserve Organic Waste Digestion Project Protocol guidelines. The greenhouse gas reduction potential was estimated as 6,532 tonnes of carbon dioxide equivalent per year (tCO2e/year), with approximately 693 m3 methane produced per day. In one year, the digester would generate an estimated 7370 kWh of energy which has the potential to power 149 homes for a year in Montgomery, VA. In addition, 4130 tonnes/year of composted digestate would be available as fertilizer for surrounding farms. / Master of Science / Currently, about one-third of the entire U.S. food supply is lost or wasted. A large portion of that food waste is sent to landfills, where it produces methane, a greenhouse gas. Instead, food waste can be broken down to produce biogas during anaerobic digestion. Anaerobic digestion is a process in which microorganisms break down organic materials in the absence of oxygen to produce biogas and digestate, a material used as a soil amendment or fertilizer. However, anaerobically digesting food waste often leads to process instability and failure due to a buildup of undesirable intermediates. Microorganisms in anaerobic digestion require certain trace elements (i.e., iron, copper) that food waste often lacks; therefore, supplementing key trace elements may improve the anaerobic digestion of food waste. This research aimed to assess the effect of supplementing key trace elements (iron, copper, zinc, calcium, magnesium, nickel, manganese, selenium, molybdenum, cobalt) on organic matter degradation and methane yield. Methane yield of food waste with and without the inorganic salt trace element was determined by the gas density-based biomethane potential method at mesophilic (37°C) conditions over 30 days. The average cumulative biogas produced was 41% higher, and the average total cumulative methane produced was 23% higher in the bottles containing a trace element supplement. No significant difference was seen in the two groups when comparing organic matter degradation. These results demonstrate that supplementing trace elements can improve biogas and methane production. Greenhouse gas reductions from anaerobically digesting food waste instead of sending it to landfills were determined for Montgomery, VA. The results from the biomethane potential test informed the design of a theoretical community digester. Greenhouse gas reduction was calculated using the Climate Action Reserve Organic Waste Digestion Project Protocol equations. The greenhouse gas reduction was determined as 6,532 tonnes of carbon dioxide equivalent per year (tCO2e/year). The digester would produce approximately 693 m3 methane/day, which has the potential to power 149 homes for a year in Montgomery, VA. In addition, 4130 tonnes/year of compost would be produced and available as a fertilizer for surrounding farms.